Maintenance of relay protection and automation. Recommendations for drawing up maintenance schedules for relay protection and emergency automation devices. Switching devices in relay circuits
Good day, dear friends.
There are a lot of questions on this topic: Relay protection and automation, but it's simpler RZA.
I devoted today’s article to organizing the maintenance of relay protection and automation devices, and it will be exactly like this, regardless of the complexity of the electrical equipment you use.
Let's start with the fact that the period of operation of the device or its service life before write-off is determined by the wear and tear of the device to such a state where its restoration becomes unprofitable.
The service life of the device, starting with the check when switching on again, usually includes several overhaul periods, each of which can be divided into characteristic periods from the point of view of reliability ( Reliability is the property of a device to maintain over time, within established limits, the values of parameters that characterize the ability to perform required functions in given modes and conditions of use, maintenance, repairs, storage and transportation) stages:
— running-in period;
- period of normal operation.
The following types of maintenance of relay protection and automation devices are established: electrical networks 0.4-35 kV:
— check when switching on again (adjustment);
— first preventive control;
— preventive control;
— preventive restoration (repair);
— testing (test control);
— technical inspection.
In addition, during operation, an extraordinary or post-accident inspection may be carried out.
Check (adjustment) Inspection of relay protection and automation devices when switching on again should be carried out when commissioning a newly installed, separate connection or when reconstructing relay protection and automation devices at an existing facility. This is necessary to assess the serviceability of equipment and secondary circuits, the correctness of connection diagrams, adjusting relays, and checking the functionality of devices ( Working condition is a state of devices in which the values of parameters characterizing the ability to perform specified functions comply with the requirements of regulatory, technical and design documentation.) Relay protection and automation in general. The check when switching on again must be carried out by the personnel of the relay protection service or a specialized commissioning organization.
If the check for new switching was carried out by a third-party commissioning organization, then switching on of new and reconstructed devices is carried out after their acceptance by the relay protection service.
Preventive control relay protection devices is carried out in order to identify and eliminate problems arising during operation possible malfunctions its elements that can cause unnecessary operations or failures of relay protection devices.
The first preventive control after putting the relay protection device into operation is carried out mainly in order to identify and eliminate run-in failures ( Run-in failures occur during the initial period of operation and are caused mainly by shortcomings in production technology and insufficient quality control of component elements of devices during manufacturing. For relay protection and automation devices, the causes of running-in failures can also be errors during installation and commissioning, poor quality of commissioning.) that arise during the initial period of operation.
Preventative recovery is carried out in order to check the serviceability of equipment and circuits, compliance of the settings and characteristics of the relay with the specified ones, restoration of worn-out equipment and its parts, checking the relay protection and automation device as a whole.
Preventive restoration is also carried out in order to restore individual less reliable (having a short resource or a high rate of resource depletion) device elements: relays RT-80, RT-90, IT-80, IT-90, ET-500, EH-500, EV- 100, EV-200, RTV, RVM, RP-341, etc. Depending on environmental conditions and the condition of the equipment, the scope of partial restoration of relay protection and automation devices located in outdoor cabinets can be expanded.
Testing is carried out in order to check the performance of relay protection devices.
Testing can be carried out using built-in testing elements or by simulating the triggering of relay protection devices.
Test control is carried out for devices that have built-in means of manual test control.
The need and frequency of testing or test control are determined by local conditions and approved by the chief engineer of the enterprise.
Correct operation of relay protection devices for 6 months. before the testing period is equivalent to testing.
Extraordinary inspection is carried out in case of partial changes in circuits or reconstruction of relay protection and automation devices, if it is necessary to change the settings or characteristics of relays and devices, as well as to eliminate deficiencies discovered during testing.
Post-accident inspection is carried out to determine the causes of operational failures or unclear actions of relay protection and automation devices. Extraordinary and post-emergency inspections are carried out according to programs drawn up by MS RZA, approved by the chief engineer of the enterprise.
A short digression about refusals:
Refusal called a violation of the operable state of the device. There are characteristic types of failures that differ:
if possible, predicting the onset of failure - gradual and sudden failures;
according to the time of failure occurrence - running-in failures, failures during normal operation and degradation failures.
In this case, failures can be either gradual or sudden.
Gradual failures occur as a result of changes in one or more parameters of the device or the state of its elements due to various physical and chemical processes that arise as a result of prolonged operation.
In relay protection and automation devices, these processes include: dusting of internal parts of relays and devices, formation of carbon deposits and cavities on contacts, misadjustment of the mechanical part of the relay, loosening of screw contact connections, decreased insulation resistance, changes in the characteristics of the device or its individual elements. When timely preventive measures are carried out, these changes in the parameters or state of the device and its elements can be detected by monitoring and diagnostic methods, and possible failures can be prevented by adjusting, replacing or restoring the elements.
Sudden failures characterized by abrupt changes in the values of one or more device parameters. The causes of sudden failures are physical and chemical processes that occur rather slowly over time.
Failures during normal operation occur after the end of the running-in period, but before the onset of degradation failures. This is the longest period of total operating time in which the number of failures is approximately constant and has the least significance.
Degradative failures are caused by natural processes of aging, wear and corrosion, subject to compliance with established rules, design, manufacturing and operation standards. These failures occur when the device as a whole or its individual elements approaches a limiting state due to aging or wear conditions at the end of its full service life or between repairs. At proper organization maintenance, these failures can be prevented by timely replacement or restoration of elements. In this case, the replacement period should be less than the average wear time of the element. If timely replacement is not carried out, the number of degradation failures increases.
Running-in failures, failures during normal operation and degradation failures are random events, but obey general laws.
It is necessary to distinguish between failure of a protection device as an event of loss of functionality and failure of operation as an event of failure to perform a specified function when a corresponding requirement arises.
Periodic technical inspections are carried out in order to check the condition of the equipment and relay protection circuits, as well as the compliance of the position of the linings and switching devices with the operating mode of the equipment.
Now let's talk about frequency of maintenance of relay protection and automation devices.
For relay protection and automation devices, the maintenance cycle is set from three to twelve years .
The maintenance cycle is understood as the period of operation of the device between the two nearest preventive restorations, during which the established types of maintenance are performed in a certain sequence.
What determines the duration of the maintenance cycle? On the degree of influence of various factors on relay protection devices.
Based on the degree of influence of various environmental factors on devices in electrical networks of 0.4-35 kV, two categories of premises can be distinguished.
Co. II category These include rooms with a wide range of fluctuations in ambient temperature, in which there is relatively free access to outside air (metal rooms, cells of the KRUN type, complete transformer substations, etc.), as well as rooms located in areas with increased environmental aggressiveness.
The maintenance cycle for relay protection and automation devices installed in premises of category I is assumed to be 12, 8 or 6 years, and for relay protection and automation devices installed in premises of category II, it is accepted to be equal to 6 or 3 years, depending on the type of relay protection and automation devices and local conditions affecting to accelerate wear of devices (see table).
The maintenance cycle for relay protection and automation devices is established by order of the chief engineer of the enterprise.
For non-essential connections in premises of category II, the duration of the maintenance cycle of relay protection and automation devices can be increased, but not more than twice. In order to combine the maintenance of relay protection and automation devices with the repair of main equipment, it is allowed to postpone the planned type of maintenance for a period of up to one year. In some justified cases, the duration of the maintenance cycle for relay protection and automation devices can be reduced.
The maintenance cycles indicated in the table refer to the period of operation of relay protection and automation devices, corresponding to the full service life of the devices. Based on the operating experience of relay protection and automation devices based on electromechanical components installed in category I premises, their total average service life is 25 years and for devices installed in category II premises it is 20 years.
IN technical documentation For relay protection and automation devices based on microelectronic and electronic components, the full average service life is usually set at 12 years. Operation of electromechanical, microprocessor and electronic based relay protection and automation devices beyond the specified time limits can only be permitted in satisfactory condition and a reduction in the maintenance cycle established by the enterprise management.
The greatest number of electronic equipment failures occurs at the beginning and end of their service life, so it is recommended that these devices have shorter inspection periods in the first two to three years and after 10 to 12 years of operation. It is recommended to set the operating periods between the next two preventive restorations for these devices in the first years of operation to no more than 6 years. As operating experience is gained, the maintenance cycle can be extended to 12 years.
The maintenance cycle for 0.4 kV circuit breakers is recommended to be 3 or 6 years.
Planned maintenance of relay protection and automation devices of electrical networks of 0.4-35 kV should, if possible, be combined with repairs of main electrical equipment.
The first preventive control of relay protection and automation devices should be carried out after 10-18 months. after turning on the device.
Frequency of maintenance of equipment and secondary circuits of devices remote control and the alarm received is the same as for the corresponding relay protection devices.
The frequency of technical inspections of equipment and circuits is established in accordance with local conditions.
Test control (testing) of devices based on microelectronics is recommended to be carried out weekly at substations with personnel on duty, and at substations without personnel on duty - whenever possible, but at least once every 12 months.
For microelectronic and microprocessor devices Before switching on a new relay, as a rule, training should be carried out by supplying the device with operating current for 3 - 4 days and, if possible, operating currents and voltages with switching on the device with an effect on the signal. After the training period has expired, a test control is carried out and if there are no malfunctions, the relay protection device is switched to shutdown.
Removing dust from external surfaces, checking the reliability of contact connections, checking the integrity of glass, the condition of housing seals, etc. microprocessor and electromechanical relay protection devices are performed in the usual way. During an internal inspection, cleaning the internal modules of microprocessor-based relay protection and automation devices from dust should be done with a vacuum cleaner to prevent damage to the devices by static discharge. Please note that manufacturers guarantee normal work electronic devices and performing warranty repairs of relay protection and automation systems during a limited period of operation while maintaining the factory seals. Taking this into account, it is not recommended to open the casings of these relay protection devices during the warranty period.
If microelectronic based relay protection and automation devices malfunction, the device must be repaired at the manufacturer during the warranty period. During the subsequent period of operation, repairs are carried out under an agreement with the manufacturer or in basic laboratories by qualified specialists.
Methods for checking microprocessor relay protection devices are given in technical descriptions and operating instructions from manufacturers.
I'll stop there today.
RUSSIANJOINT STOCKSOCIETYENERGY
ANDELECTRIFICATION «
UESRUSSIA»
RULES
TECHNICAL
SERVICES
DEVICES
RELAYPROTECTION,
ELECTROAUTOMATICS
,
REMOTEMANAGEMENT
ANDALARMSPOWER PLANTS
AND
SUBSTATIONS 110 - 750
kV
RD 153-34.0-35.617-2001
3-
e
edition
,
recycled
And
supplemented
SERVICEADVANCEDEXPERIENCEORGRES
Moscow2001
DevelopedOpen joint stock company"Company for setting up, improving technology and operating power plants and networks of ORGRES"
Performers V.A. BORUKHMAN, V.S. GONCHAROVA, A.V. GRIGORIEV, N.P. SANTURYAN
ApprovedDepartment of Scientific and Technical Policy and Development of RAO UES of Russia 01/20/2001
First Deputy Chief A.P. LIVINSKY
| RULES
TECHNICAL
SERVICES | RD 153-34.0-35.617-2001 |
Put into effect
from 01.03.2001
These Rules are mandatory for workers involved in setting up and operating relay protection and electrical automation devices (RPA) at the enterprises of Intersystem Electric Networks (IES) and JSC-Energo, at power plants of RAO UES of Russia.
The rules determine the types, frequency, programs and volumes of maintenance of relay protection and automation devices, remote control and signaling devices (hereinafter referred to as relay protection devices), high-frequency relay protection channels, current and voltage transformers.
When drawing up these Rules, the “Rules for the maintenance of relay protection devices, electrical automation, remote control and signaling of power plants and substations 110 - 750 kV: RD 34.35.617-89” were used, as well as proposals and materials from a number of power systems, power plants, electrical network enterprises, development organizations and manufacturers of relay protection and automation devices.
With the release of these Rules, “Rules for the maintenance of relay protection devices, electrical automation, remote control and signaling of power plants and substations 110 - 750 kV: RD 34.35.617-89” (M.: SPO Soyuztekhenergo, 1989) are considered no longer in force.
1 . GENERAL PROVISIONS
1.1 . These Rules are mandatory for workers involved in setting up and operating relay protection and electrical automation devices (RPA) at the enterprises of Intersystem Electric Networks (IES) and JSC-Energo, at power plants of RAO UES of Russia.
1.2 . The rules determine the types, frequency and maintenance programs for relay protection and automation devices, remote control and signaling devices (hereinafter referred to as relay protection devices), as well as the scope of maintenance of standard panels, cabinets, sets, units and devices of relay protection and automation devices, high-frequency relay protection channels, current and voltage transformers .
1.3 . Methods for checking and testing devices and apparatus are given in the guidelines and instructions that should be used when carrying out maintenance (Appendix ).
2. MAINTENANCE SYSTEM FOR RPA DEVICES
2.1. Basic concepts and terms in the field of relay protection and automation reliability
2.1.1 . Reliability is the property of an object to maintain over time, within established limits, the values of all parameters that characterize the ability to perform required functions in given modes and conditions of use, maintenance, repairs, storage and transportation.
2.1.2 . Working condition is the state of an object in which the values of all parameters characterizing the ability to perform specified functions comply with the requirements of regulatory and technical and (or) design (project) documentation.
2.1.3 . Refusal An event is called a violation of the operational state of an object.
If there are no failures at all, then the object is 100% reliable. However, any real object, regardless of the adopted maintenance system, is subject to failures.
It is advisable to highlight the following characteristic types of object failures, dividing them into two groups:
if possible, predict the onset of failure - gradual failures and sudden failures;
according to the time of failure occurrence - running-in failures, failures during normal operation and degradation failures.
In this case, failures of the second group can be either gradual or sudden.
Gradual failures arise as a result of a gradual change in one or more parameters of an object or the state of its elements due to the occurrence of various mechanical, physical and chemical processes over time of operation.
In relay protection and automation devices, these processes include: dusting of the internal parts of the relay, formation of carbon deposits and cavities on the contacts, misadjustment of the mechanical part of the relay, loosening of screw contact connections, reduction of insulation resistance, loss of characteristics of the device or its individual components and elements, etc. When timely preventive measures are carried out, these changes in the parameters or state of the device and its elements can be detected by accepted methods of monitoring and diagnostics, and possible failures can be prevented by adjusting, replacing or restoring the elements.
Sudden failures characterized by abrupt changes in the values of one or more object parameters. The causes of sudden failures can be hidden defects, as well as mechanical, physical and chemical processes that can occur quite slowly over time, but unlike gradual failures, the onset of a sudden failure cannot be predicted by accepted monitoring and diagnostic methods.
A typical reason for such a failure may be, for example, a decrease in the resistance of the interturn insulation of the relay winding.
Run-in failures , occurring during the initial period of operation, are caused mainly by shortcomings in production technology and insufficient quality control of components and objects in general during their manufacture. For relay protection and automation devices, the causes of running-in failures can also be errors during installation and commissioning, poor quality of commissioning, etc.
Run-in failures for continuous equipment are usually eliminated during the run-in process, i.e. operation of equipment for a certain time under conditions close to operational ones. For devices that operate quite rarely, which include relay protection and automation devices, the running-in period can be long. As defective elements are identified and eliminated, the number of running-in failures per unit of time decreases.
Failures during normal operation occur after the end of the running-in period, but before the onset of degradation failures. This is the longest period of total operating time, in which the number of failures per unit time is almost constant and has the smallest value.
Degradative failures are caused by the natural processes of aging, wear, corrosion and fatigue, subject to compliance with all established rules and regulations for design, manufacture and operation. These failures occur when the object as a whole or its individual elements approaches a limiting state due to aging or wear conditions at the end of its full or overhaul life. With proper maintenance, these failures can generally be prevented by timely replacement or restoration of elements. In this case, the replacement (restoration) period must be less than the average aging (wear) time of the element. If timely replacement (restoration) is not carried out, then the number of degradation failures per unit of time begins to increase.
Loss of functionality of devices can also occur due to personnel errors during their technical or operational maintenance, as well as be a consequence of the influence of external factors, the significance of which goes beyond the limits established by the regulatory and technical documentation, or the simultaneous influence of several external factors not provided for by this documentation, the significance of each of which does not exceed the established limits. In this case, loss of performance can be in the nature of both sudden and gradual failure during any period of operation.
2.1.4 . Run-in failures, failures during normal operation and degradation failures are random events, but are subject to various general patterns of random events.
A sequence of random events over time is called stream of events. Therefore, the sequence of failures is called a stream of failures. One of the failure flow characteristics for repaired products, which include relay protection devices, is failure flow parameter- probable number of failures per unit of time.
During the initial period of operation, during the running-in period, the failure flow parameter decreases as defects are identified and eliminated.
After the end of the running-in period, it begins period of normal operation, in which the failure flow parameter is almost constant. After the period of normal operation comes period of degradation(aging and wear), in which the failure flow parameter begins to increase.
Run-in failures are eliminated during the break-in period by replacing failed elements and eliminating identified faults.
To prevent degradation failures, timely preventive replacement (restoration) of the element is necessary, even if it has not failed, at the end of the period of normal operation.
Sudden failures generally cannot be prevented by replacing components during normal operation. On the contrary, replacing serviceable elements can increaseimprove the failure flow parameter due to the occurrence of run-in failures in newly installed elements. It should be noted that a number of the features of relay protection outlined below from the point of view of reliability determine a specific approach to the prevention of sudden failures of relay protection devices.
2.1.5 . Relay protection devices (as opposed to continuous devices) can be classified as devices with static readiness for action. Relay protection performs its functions on demand, which is a short circuit or other violation of the normal operation of the protected equipment. Therefore it is necessary to distinguish device failure protection as an event of loss of performance and failure of operation as an event of failure to perform a specified function when a corresponding requirement arises. Failure of a device usually does not occur simultaneously with the occurrence of a requirement for operation and, therefore, failure of operation can be prevented if preventive maintenance is carried out in the interval between the moment the failure occurs and the moment the requirement arises. Therefore, the flow of operational failures depends not only on the flow of device failures, but also on the organization of maintenance, as well as on the quality of its implementation.
Moreover, since a device failure can only turn into a performance failure when a performance requirement arises, the flow of performance failures also depends on flow of operational requirements.
2.2. Types of maintenance of relay protection and automation devices
2.2.1 . The period of operation or service life of a device before write-off is determined by the moral or physical wear and tear of the device to such a state that its restoration becomes unprofitable. The service life of the device, starting with the test when it is turned on again, usually includes several periods between repairs, each of which can be divided into stages characteristic from the point of view of reliability: the running-in period, the period of normal operation and the wear period.
The following types of scheduled maintenance of relay protection and automation devices are established:
check when switching on again (adjustment);
first preventive control;
preventive control;
preventive restoration (repair);
test control;
testing;
technical inspection.
In addition, the following types of unscheduled maintenance may be performed during operation:
extraordinary inspection;
post-accident inspection.
2.2.2 . When restarting relay protection devices, including secondary circuits, instrument transformers and drive elements of switching devices related to relay protection devices, checks are carried out:
before turning on newly installed devices;
after reconstruction of existing devices associated with the installation of new additional equipment, alteration of equipment in operation, or after installation of new secondary circuits.
If the check for new switching was carried out by a third-party commissioning organization, switching on new and reconstructed devices without their acceptance by the RZAI service is prohibited.
2.2.3 . The task of maintenance during the running-in period, taking into account the features of relay protection, is to identify run-in failures as quickly as possible and prevent operational failures for this reason.
For relay protection and automation devices, running-in failures are most typical during the initial period of operation. During other periods between repairs they occur much less frequently.
The run-in period of the relay protection device begins with adjustment work before switching ondevices into operation, which, when carried out carefully, ensure the identification and elimination of most of the running-in failures. However, there is always a possibility that some defects will not be detected or will appear after adjustment. In addition, during setup, hidden defects in elements may not appear, which will become apparent some time after the device is put into operation. These may include, for example, weakened turn-to-turn insulation of relay and transformer windings, the presence of breaks in resistance wires, hidden defects in electronic equipment.
Thus, with the completion of adjustment work and commissioning of the device, the running-in period cannot be considered complete. It is necessary to carry out another check some time after setting up, after which There is a fairly high probability that running-in failures have been identified and eliminated. This check is called the first preventive control. The timing of this control is determined mainly by two contradictory factors. On the one hand, it takes some time for hidden defects to appear and, therefore, the longer this time, the more likely their manifestation. On the other hand, with an increase in the interval between putting the device into operation and the first preventive control, the likelihood of device failure increases.
2.2.4 . The task of maintenance during the period of degradation is timely preventive restoration or replacement of worn-out device elements in order to prevent a sharp increase in the failure rate parameter. The corresponding type of maintenance, taking into account the maintainability of the vast majority of elements of relay protection devices, is called preventive restoration.
The frequency of preventive restoration of a device is determined by the frequency of restoration of its elements, which in turn is determined by the resource of these elements. Resource various elements is not the same, however, taking into account the specific operating conditions of relay protection and automation devices, it is necessary to combine the timing of preventive restorations of different elements subject to aging (wear) processes at different rates.
It is advisable to determine the frequency of preventive restoration of a relay protection and automation device by the service life of most of the equipment and elements of this device.
For fast-wearing electromechanical relays (which have a short service life), restoration is also carried out during regular preventive control. The list of equipment with a reduced service life is given in Note 2 to the table (see paragraph).
2.2.5 . The task of maintenance during normal operation, i.e. between two restorations, is to identify and eliminate any failures that have occurred and changes in device parameters in order to prevent possible operational failures. The corresponding types of maintenance are called preventive inspection and test inspection.
Preventive control consists of checking the performance of the entire relay protection device.
Test control as an additional type of maintenance is used for microelectronic and microprocessor devices that have the appropriate built-in tools. During test control, the functionality of a part of the device is usually checked.
The frequency of preventive and test control is determined by a number of factors:
failure flow parameter;
performance requirements flow parameter;
damage from failure of the relay protection device to function;
costs of preventive control;
the likelihood of personnel errors in the process of preventive control.
In addition to preventive monitoring, during normal operation it is provided, if necessary, to carry out periodic testing(see paragraph).
The purpose of periodic testing is to additionally check the performance of the least reliable elements of relay protection and automation devices: time relays with a clock mechanism, process sensors, drives of switching devices (actuators).
2.2.6 . When partially changing circuits or reconstructing relay protection and automation devices, when restoring circuits broken due to the repair of other equipment, if necessary, changes to the settings or characteristics of relays and devices are carried out extraordinary inspections.
Post-accident checks are carried out to determine the causes of operational failures or unclear actions of relay protection and automation devices.
External inspections should be carried out periodically technical inspections equipment and secondary circuits, checking the position of switching devices and test blocks.
2.3. Frequency of maintenance of relay protection and automation devices
2.3.1 . All relay protection devices, including secondary circuits, instrument transformers and drive elements of switching devices related to relay protection devices, must be periodically subjected to maintenance.
Depending on the type of relay protection and automation devices and their operating conditions in terms of exposure to various environmental factors, the maintenance cycle is set from three to eight years.
The maintenance cycle is understood as the period of operation of devices between the two nearest preventive restorations, during which the established types of maintenance provided for in these Rules are performed in a certain sequence.
2.3.2 . For relay protection and automation devices of 110 - 750 kV substations, including booster substations of power plants, the maintenance cycle is assumed to be eight years for devices on an electromechanical element base and six years for microelectronic and microprocessor based devices 1.
1 Devices based on microelectronics include devices whose measuring and logical parts are mainly or completely made on integrated circuits.
2.3.3 . For relay protection and automation devices of power plants, the maintenance cycle depends on the categories of premises in which they are installed.
K I categories include dry heated rooms with minor vibration and dust, in which there are no shock effects (main control room, main control room, relay boards).
Premises II categories are characterized by a wide range of fluctuations in ambient air temperature, slight vibration, the presence of single impacts, and the possibility of significant dust formation (RUSN panels 0.4 kV, relay compartments of 6 kV switchgear).
Premises III categories are characterized by the presence of constant high vibration (AGP chamber, areas near rotating machines).
The maintenance cycle of relay protection and automation devices, depending on the category of the room where the device is installed, is taken to be eight, six and three years, respectively.
The maintenance cycle for circuit breaker releases of all types is assumed to be six years.
For non-essential connections with a voltage of 0.4 - 6 kV of power plants, the duration of the maintenance cycle for remote control and signaling devices can be doubled compared to the duration of the maintenance cycle for relay protection and automation devices of these connections (but not more than eight years).
2.3.4 . Established in paragraphs. And The duration of the maintenance cycle for relay protection and automation devices, by decision of the chief engineer of the enterprise, can be increased or reduced depending on the specific operating conditions, the duration of operation from the moment of commissioning, the actual condition of each specific device, as well as the qualifications of the maintenance personnel of the relay protection and automation system. For relay protection and automation devices of the main circuit of power plants, equipment and power transmission lines of substations under the jurisdiction or control of the power system dispatcher, this decision must be agreed upon with the relay protection and automation service of JSC-Energo; for other relay protection and automation devices such approval is not required.
2.3.5 . In order to combine the maintenance of relay protection and automation devices with the repair of main equipment, it is allowed to postpone the planned type of maintenance for a period of up to two years.
2.3.6 . With a three-year maintenance cycle duration, preventative monitoring between preventive restorations should not normally be carried out.
2.3.7 . The first preventive inspection of relay protection, remote control and alarm devices should be carried out after 10 - 15 months. after putting the device into operation. For relay protection and automation devices of power units, the first preventive control is combined with the first major overhaul of the equipment.
2.3.8 . For such secondary connection devices as remote control, alarm, blocking, only preventive restorations, testing and inspections are carried out at the frequency established for the corresponding relay protection devices.
2.3.9 . Test control for devices based on microelectronics must be carried out at least once every 12 months.
2.3.10 . For microelectronic-based relay protection and automation devices with built-in test control means, as a rule, training should be provided before the first commissioning. The training consists of applying it to the device for 3 - 5 days. operating current and, if possible, operating currents and voltages; In this case, the device must be turned on and act on the signal. After the training period has expired, a test check of the device should be carried out, and if there are no malfunctions, the relay protection device should be switched off.
If it is impossible to carry out training, the first test control should be carried out within two weeks after commissioning.
2.3.11 . The frequency of technical inspections of equipment and secondary circuits is established by MS RZAI in accordance with local conditions, but at least twice a year.
2.3.12 . Testing of ATS devices of MV TPP mechanisms must be carried out by operating personnel at least once every six months, and testing of ATS devices of MV power inputs - at least once a year. Testing of automatic reclosure devices of power transmission lines should be carried out at least once a year.
The need and frequency of testing other relay protection devices are determined by local conditions and approved by the decision of the chief engineer of the enterprise.
Correct operation of the devices within a three-month period before the scheduled date can be counted towards the next testing.
2.3.13 . The frequency of the types of maintenance provided for by these Rules is given in the table.
The maintenance cycles indicated in the table refer to the period of operation of relay protection and automation devices within the full service life. Technical specifications for relay protection and automation devices based on electromechanical and microelectronic bases, the average total service life is set to 12 years.
Based on operating experience, the actual service life of relay protection and automation devices based on electromechanical components under normal operating conditions and carrying out established maintenance is at least 25 years. There is no such experience yet for microelectronic devices.
Operation of relay protection and automation devices beyond the established service life is possible if the equipment and connecting wires of these devices are in satisfactory condition and if it is necessary to reduce the maintenance cycle (see paragraph).
Ministry of Education and Science of the Russian Federation
Federal State Budgetary Educational Institution
higher professional education
"Ufa State Petroleum Technical University"
Department of Electrical Engineering and Electrical Equipment of Enterprises
in the discipline "Operation of electrical equipment"
"Repair and maintenance of relay protection devices"
Ufa 2014
Introduction
1. Basic requirements for relay protection
Classifications and operating principles of relay protection
Repair and maintenance of relay protection devices
Instrumentation when performing maintenance work on relay protection devices
Qualification requirements for personnel carrying out work
Safety instructions
7. Personal protective equipment used during work
Conclusion
List of used literature
relay protection instrument safety
Introduction
In electro energy systems damage and abnormal operating conditions may occur.
The development of accidents can be prevented quick shutdown damaged area using special automatic devices - relay protection.
The purpose of relay protection is to automatically disconnect the damaged part of the electrical system (electrical installation) using switches; If the fault (for example, a ground fault in networks with an isolated neutral) does not directly disrupt the operation of the electrical system, relay protection is allowed to act only on the signal. Relay protection also reacts to dangerous, abnormal operating conditions of electrical system elements (for example, overload, increased voltage in the stator winding of a hydrogenerator); Depending on the operating mode and operating conditions of the electrical installation, relay protection must be carried out to act on the signal or to disconnect those elements, which if left in operation can lead to damage.
1. Basic requirements for relay protection
Basic requirements for relay protection:
Selectivity
Performance
Sensitivity
Reliability
Classifications and operating principles of relay protection
Typically, relay protection devices consist of several relays connected to each other according to a specific circuit.
The relay is automatic device, which comes into action (triggered) at a certain value of the input quantity acting on it.
In relay technology, relays with contacts are used - electromechanical, contactless - on semiconductors or on ferromagnetic elements. The first ones close or open contacts when triggered. For the second, at a certain value of the input value, the output value, for example voltage, changes abruptly.
Each protection set and its circuit are divided into two parts: reactive and logical.
The reacting (measuring) part is the main one, it consists of main relays that continuously receive information about the state of the protected element and react to damage or abnormal conditions by sending appropriate commands to the logical part of the protection.
The logical part (operational) is auxiliary, it perceives the commands of the reacting part and, if their value, sequence and combination correspond to the given program, it carries out pre-programmed operations and supplies a control pulse to turn off the circuit breakers. The logical part can be performed using electromechanical relays or circuits using electrical devices - lamp or semiconductor.
In accordance with this, the division of relay protective devices is also divided into two groups: the main ones, which respond to damage, and the auxiliary ones, which act on the command of the former and are used in the logical part of the circuit.
Signs of the occurrence of a short circuit can be an increase in current, a decrease in voltage and a decrease in the resistance of the protected area, characterized by the ratio of voltage to current at a given point in the network.
Accordingly, the following are used as responsive relays: current relays that respond to the current value; voltage relays that respond to voltage levels; resistance relays that respond to changes in resistance.
In combination with the indicated relays, power relays are often used that respond to the magnitude and direction (sign) of the short-circuit power passing through the protection installation site.
Relays that operate when the value to which they react increases are called maximum, and relays that operate when this value decreases are called minimum.
For protection against abnormal conditions, as well as for protection against short circuits, current and voltage relays are used. The former serve as relays that respond to overload, and the latter - to a dangerous increase or decrease in voltage in the network. In addition, a number of special relays are used, for example, a frequency relay that operates in the event of an unacceptable decrease or increase in frequency; thermal relays that respond to an increase in heat generated by current during reboots, and some others.
The auxiliary ones include: time relays, which serve to slow down the action of protection; indicator relays - for signaling and recording the protection action; intermediate relays, transmitting the actions of the main relays to open circuit breakers and serving for mutual communication between protection elements.
Repair and maintenance of relay protection devices
Preparatory work. A complete set of design and factory documentation, necessary instructions and test programs, approved settings for setting up protection devices and electrical automation are selected (they are obtained from the relevant operating services). Using verified circuit diagrams, the wiring diagrams of panels and consoles, rows of clamps, cable logs, etc. are checked. When analyzing the circuit diagrams, the possibility of adjusting the specified settings on the design devices is checked, and relays that need to be replaced are identified.
A workplace is organized, the necessary testing devices, measuring instruments, tools and devices, passport protocols for all devices of the connection being established are prepared, and permission to work is issued.
To avoid erroneously applying voltage to adjacent panels and devices, all cables connected to the terminal rows of the panel being tested must be disconnected.
External and internal inspection. The compliance of the installed equipment with the design and specified settings is checked.
The correct marking of cables, cable cores, and wires is checked visually and by checking the continuity of the circuits; installation location and grounding of secondary circuits; the presence of the necessary inscriptions on panels and equipment, usually carried out by operating personnel.
On the device being adjusted (panel, switchboard, remote control), the compliance of the external installation with the circuit and wiring diagrams is checked, by rocking and tugging on the wire with tweezers, the reliability of the soldering is checked, all contact connections on the rows of clamps and devices are tightened. As a rule, the correct installation is not checked on standard serial panels.
During an internal inspection and check of the mechanical part of the equipment, the absence of visible damage, the reliability of bolted connections and soldering, and the condition of the contact surfaces are checked. By touching the relay with your hand, check the movement, movement and absence of rubbing of the moving parts, the presence of regulated backlashes, gaps, deflections, dips, etc.
A preliminary check of insulation resistance is carried out to control the insulation resistance of individual units of the connection being established (control panels, panels, control cables, secondary windings of current and voltage transformers, etc.) before applying test voltage to them from testing devices. The measurement is carried out with a 1000-2500 V megohmmeter between separate groups of electrically unconnected circuits (current, voltage, operating current, alarm, etc.) relative to the ground and to each other. To ensure increased reliability, the insulation resistance is checked between the conductors of the gas protection cable and between the conductors of the cable from the voltage transformers to the cabinet where the protective elements are installed - circuit breakers or fuses. Equipment not designed for a test voltage of 1000 V (for example, magnetoelectric and polarized relays) is excluded from the circuit during checks and is tested in accordance with factory standards.
Checking the electrical characteristics and adjusting the specified operating settings is carried out in accordance with the requirements of maintenance rules, current instructions, including factory ones, for this specific type of device.
The work of checking the electrical characteristics is completed by adjusting the specified settings, after which all secondary circuits of this connection are assembled by connecting cable cores on rows of terminals, with the exception of communication circuits with devices in operation.
Insulation measurement and testing is carried out in a fully assembled circuit with casings, covers, relays, doors, etc. of each group of electrically unconnected secondary circuits installed and closed. Electrical insulation strength is tested with a voltage of 1000 V alternating current for 1 minute relative to the ground. Before and after applying an alternating test voltage, the insulation resistance of the tested circuits is measured with a 1000-2500 V megohmmeter. Elements and circuits with an operating voltage of 60 V and below are excluded from these checks.
Checking the interaction of device elements. At an operating voltage of 0.8 , the correct interaction of protection relays, electrical automation, control and signaling is checked. The interaction is checked in accordance with circuit diagram, by manually closing and opening the relay contact circuits, while checking the absence of bypass circuits, the correct operation of the circuit when switching overlays, switches, test blocks, etc. On the rows of terminals of the device being tested, the presence and absence of signals intended to influence devices located at work. A comprehensive test is carried out according to an agreed and approved program by simulating various emergency modes at the rated voltage of the operating current supplied according to the design diagram from the DC switchboard. For this purpose, various combinations of currents and voltages are supplied from the testing device to the connection under test, which correspond to the parameters of emergency modes (this test is carried out with the relay covers closed). When simulating each mode, the operating time of each of the protection stages on the contacts of the output relays is measured, and the correct operation of interlocks and alarms is checked. To avoid repeated impacts on switches, disconnectors, valves, gate valves, etc., it is necessary to ensure reliable removal of output protection circuits from operation. After checks in various modes all connections with other devices and devices are restored (especially carefully connect equipment that is in operation). A comprehensive test ends with testing the effect on switching equipment and monitoring interaction with devices of other connections. The results of the check are recorded in the corresponding entry in the relay protection log, after which work in the operational circuits of this connection cannot be carried out without special permission. Preparing the device for use. Before switching on, the panels and rows of clamps are re-inspected, the position of the connecting bridges and jumpers, the position of the overlays in the shutdown circuits, the absence of disconnected and bare wires and cable cores, and the presence of grounding in the corresponding circuits are checked. When the equipment is turned on again, all protections, including those not tested by operating current, are put into operation with a shutdown effect; immediately after switching on, the devices are checked under load jointly by commissioning personnel and local service specialists, including operational personnel. This test of the device under load with operating current and voltage is final, confirming the correct activation and behavior of individual relays and the device as a whole. When checking with operating current and voltage, the correct execution of the voltage circuits is first checked, and then the correct execution of the current circuits is checked by taking a vector diagram of the currents and evaluating it based on the actual direction of power in the primary network. To monitor the integrity of the neutral wire, the unbalance current in it is necessarily measured; by creating appropriate modes, the flow through neutral wire phase current. After completing the load test, carefully inspect and restore the jumpers on all relays whose mode changed when testing them with operating current. An appropriate entry is made in the relay protection log about the status of the tested devices and the possibility of putting them into operation. Instrumentation when performing maintenance work on relay protection devices In the last two decades, a new generation of testing devices has appeared for servicing simple and complex protection, which includes devices of the RETOM type, which allow both manual and automatic testing of relay protection and automation devices using a computer according to specified programs and minimizing the cost of manual labor for switching in relay protection and automation circuits and drawing up protocols. Among a large number of other complete testing devices that facilitate the maintenance of complex relay protection and automation devices (hereinafter referred to as RPA), previously the most widely used devices were U5053, EU5001. For example, these devices became the prototype for more advanced Uran installations. Devices of the "RETOM" type · They generate AC and DC current and voltage signals, independently controlled by magnitude, phase and frequency. This allows you to manually or automatic mode check the characteristics of the automatic protective equipment during a short circuit various types and other abnormal modes of power systems (for example, during swings and asynchronous movement). During automatic testing, these signals can be supplied to the URZA both with a push, changing from step to step, and with a smooth (step) change. · They control the switching necessary for automatic testing in the circuit breaker protection circuit using discrete (mainly contact) signals, synchronized according to a given program with analog signals. · They control the reaction of the automatic relay protection system - it receives and processes the discrete and analog signals coming from it to check the parameters and characteristics of the automatic relay protection equipment. RETOM discrete inputs are galvanically isolated, universal and allow connection even to relay contacts under DC voltage up to 250 V and to potential IC outputs. · Automatically evaluates correctness protective functions and accuracy of the parameters and settings of the relay protection devices. · Automatically create URZA test reports of the established form. RETOM provides the inspector with the opportunity to observe the progress of the test on a computer screen during an URZA inspection, analyze intermediate results, flexibly change test parameters and, if necessary, adjust the URZA parameters and the progress of the test itself. A number of generations of RETOM devices have already been released. This description provides brief characteristics of the RETOM-51 device, since it fully reflects the approach to maintenance of URZA, which is significantly different from previous approaches. The set of standard programs supplied with RETOM-51 includes universal programs: "manual" control of current and voltage sources; programs for checking relay current, voltage, power direction, resistance, frequency; universal stopwatch-recorder; programs for reproducing emergency processes recorded by digital recorders; RL models of the power system; a program for generating non-sinusoidal currents and voltages in the form of a sum of sinusoidal signals of given frequencies. In addition, included software for RETOM-51 there are specialized programs, including programs for testing protection devices such as EPZ-1636, ShDE-2801(02), DFZ-201, PDE-2802, OMP, AChR, autosynchronizers, differential protection with RNT and DZT relays, relays negative sequence types of RTF, electricity meters, generator excitation systems, a program for generating current and voltage signals of arbitrary shape and others. A special language has also been created for the development of test programs by the user himself. Functional diagram software and hardware measuring complex RETOM-51 (Figure 1) includes a power unit controlled by a portable personal computer (PC). Figure 1 - Functional diagram of the software and hardware measuring complex RETOM-51 Using programs designed to test individual relays or relay protection devices as a whole, the operator enters the required initial data into the PC, the PC calculates the modes necessary for testing and sends the information to the internal controller of the power unit. This controller, based on the instructions of the program, calculates digital samples of currents and voltages, transmits them to the interface module, from where these samples are fed to a digital-to-analog converter (DAC). From the output of the DAC, the required analog signals are fed through amplifiers to the RPA being tested. Control commands specified by the verification program are also supplied there through the discrete outputs of the power unit. The output signals of the tested RPA (for example, the closure of a current relay contact or the voltage on the reacting element of a differential relay) are fed to the discrete or analog inputs of the power unit, and sent to the PC through the internal controller. Here the signals are processed and the PC displays the results of the device test. These results, if desired by the operator, can be printed in the form of a protocol. A feature of the RETOM-51 type device is that there is no need to use measuring instruments when checking protection: ammeters, voltmeters, frequency meters, phase meters, stopwatches, oscilloscopes. At the same time, RETOM-51, certified as a measuring instrument, ensures the declared accuracy of the parameters of the output current and voltage signals. Initial setup performed by the manufacturer. To adjust the gains of current and voltage channels, as well as other parameters for a specific load in order to obtain increased accuracy, it is used special program adjustments, settings and corrections supplied with the device. Devices type U5053 and "Uran": Installations "Uran" and U5053 provide: · determination of voltage (current) of operation (return) of relays and other devices of alternating and direct voltage (current), including intermediate DC relays with parallel and series windings; · determination of unipolar terminals of parallel and serial windings of intermediate DC relays; · determination of the response (return) time of the relay protection or the time of the closed state of contacts (for example, an output relay or a slip contact of a time relay); · taking current-voltage characteristics; · organizing the measurement of protection time characteristics (Uran-1 allows this to be done in a cyclic mode with the accumulation of information in the installation’s memory and the calculation of average values of the measured values). Installations "Uran" and U5053, in addition to the functions listed above, provide: · checking the operation of the most common complex protections by applying three-phase voltage and single-phase current (voltage) to them with the ability to adjust the phase angle between them; · determining the response time of complex protections when simulating one-, two- and three-phase short circuits; · adjusting the frequency of the generated signal; measurement of external voltage, external current, phase angle between two external voltages and between external current and external voltage. 5. Qualification requirements for personnel carrying out the work Operational dispatch personnel at all levels of management and operational personnel at power facilities must know: the principle of operation and purpose of all relay protection and automation devices under its operational jurisdiction or control; the influence of the functioning of relay protection and automation devices on the stability and reliability of the operation of power associations, power systems and power enterprises; the importance of relay protection and automation devices in providing uninterruptible power supply consumers and the fastest elimination of damage; instructions for operational maintenance of relay protection and automation devices according to the list of instructions for his workplace; Methods for replacing disabled relay protection and automation devices. Operating personnel of power plants, substations and fire safety personnel must additionally clearly know: location of all cabinets and panels of relay protection and automation devices; the purpose and composition of each relay protection device, its interaction with various other devices installed at a given power plant or substation, or with semi-sets installed at other ends of the line, its effect on alarm devices; connections of each device with various equipment - current and voltage transformers, coupling capacitors, etc.; sources and circuits for powering relay protection and automation devices with operational direct and alternating current; principles of starting electrical automation devices; instructions for servicing each relay protection device installed at a given power plant or substation. Operating personnel of power plants, substations and fire safety personnel must be able to: practically use the instructions in the maintenance instructions specific devices RZA, their structural diagrams, power supply circuits for these devices and their connections with other devices; use all switching devices, overlays, circuit breakers, switches, etc. related to protection and automation devices, their operational circuits and voltage transformer circuits; eliminate simple faults, for example, replace burnt-out signal lamps, fuse links, identify operational current circuits shorted to ground, etc.; carry out the measurements specified in the instructions, check the serviceability and operating mode of some devices, test the operation various devices, exchange of high-frequency signals of HF protection channels; change the settings of some protections within the limits provided for by the relevant instructions; eliminate deviations from the specified mode of some devices using the methods specified in the instructions. Operational dispatch personnel of all levels of management, the duty engineer of the power plant, on his shift in accordance with the distribution of responsibilities among them for the operational maintenance of relay protection and automation devices, performs the following functions in relation to the devices under his operational control (supervision): supervises the operational personnel of power plants, substations and fire control units when they perform operations stipulated by the instructions for servicing relay protection and automation devices; gives instructions to the operating personnel of power plants, substations and the personnel of the internal security department on changes provided for in the instructions in the circuits or settings of relay protection and automation devices in the event of violations in the circuit or mode of operation of the network, power system, power plant and emergency shutdowns and restoration of normal mode; supervises the operational personnel of power plants, substations and fire control units when they eliminate various malfunctions and carry out tests of relay protection and automation devices specified in the instructions; gives permission to carry out work on relay protection and automation devices upon request, gives permission (or order) to perform work according to one-time programs or instructions and manages the execution of required operations with relay protection and automation devices, and also gives permission (order) to put disabled devices into operation after completion of work or for the commissioning of newly installed devices; takes measures to replace faulty relay protection devices and calls personnel from relay protection and other services to eliminate faults; receives information about the operation or failure of relay protection and automation devices under his control or jurisdiction from the operational personnel subordinate to him; bears responsibility for the correct use of all relay protection devices under his control or jurisdiction, and for the operations permitted by him in the relay protection devices. Operating personnel on shifts at power plants, substations, and fire control units work in accordance with job descriptions and perform, among other things, the following functions in relation to relay protection and automation devices: conducts regular monitoring of the serviceability of relay protection and automation devices, their circuits and auxiliary devices, regularly checks their serviceability and eliminates some malfunctions within the requirements of the instructions; monitors the readiness for operation of emergency oscilloscopes and event recorders and, if necessary, takes measures to restore the serviceability of these devices and instruments; carries out various testing and measurements specified in the instructions; Performs, by order of the dispatcher, changes in circuits or settings provided for in the instructions, introduction of accelerations and other operations with relay protection and automation devices caused by changes in the circuit or mode of operation of the network, power plant, system, or the need for preparation various works or other reasons; prepares the work site by order of the dispatcher, admits the personnel of the relay protection and automation services or personnel of third-party organizations to the work, and accepts the relay protection and automation devices from the said personnel into operation after the work is completed; makes records on the operation of relay protection and protection devices, weapons of mass destruction devices and transmits them to a higher-level dispatcher; is responsible for the correct and timely execution of the dispatcher’s orders and the accurate fulfillment of all requirements of the instructions for servicing various relay protection devices. Contractor personnel performing installation and commissioning work or scheduled maintenance of relay protection and automation devices at existing power plants and substations do not have the right to promptly service existing relay protection and automation devices. For all operations with existing relay protection devices or primary equipment necessary for the performance of work by contractor personnel, an application is submitted in the prescribed manner. Operations on an authorized request are performed by operational personnel on duty at the order of the dispatcher. Safety instructions Maintenance work on relay protection and automation devices and auxiliary circuits in existing electrical installations is carried out according to work orders or orders. Each employee directly involved in the work is required to undergo a medical examination and a test of knowledge of safety rules (obtain the appropriate safety group: IV qualification group for electrical personnel servicing electrical installations; V qualification group for persons responsible for electrical equipment, and others engineering and technical personnel), receive introductory briefing and targeted instruction at the workplace on safety precautions, master the methodology for carrying out the relevant work taking into account the requirements of safety regulations, and, if necessary, undergo an internship under the guidance of an experienced employee. When performing maintenance work on relay protection and automation devices, you should pay attention to Special attention to the following instructions: a) Temporary circuits assembled for setting up equipment (characterization, oscillography, etc.) must be performed on special tables. It is prohibited to use tables with a metal work surface or with a metal frame. The insulation of the connecting conductors must not be damaged. b) Temporary supply lines must be made with insulated wire (cable), securely fastened, and in places where people pass by they must be raised to a height of at least 2.5 m. d) Assembling temporary circuits for electrical tests, switching wires in the circuit, rearranging instruments and devices in it is prohibited without removing the voltage and creating a visible break in the supply network. e) During breaks and completion of maintenance work, the personnel performing the work must turn off the temporary power line, creating a visible break. f) Metal cases of portable devices and devices must be grounded (grounded and zeroed). g) When using complete test devices, measures must be provided to prevent access to live terminals. When connecting the test device to circuits that can be grounded (current, voltage circuits), you must ensure that there is no galvanic connection between the input and output terminals of the device. If such a connection exists, the ground connections should be temporarily disconnected. In all cases, you must carefully read the safety rules when using the test device. h) Workplace should be comfortable and sufficiently illuminated in accordance with the requirements of SNiP 23-05-95. "Natural and artificial lighting" .
i) When performing work, you should strictly ensure that the left and right hand did not simultaneously touch elements or points of the circuit that are under a voltage of 36 V or more, and grounded objects and devices (grounded housings of panels, instruments, stands, central heating radiators, etc.). j) If there are capacitors in the circuits of relay protection and automation devices, if it is necessary to operate in these circuits, the capacitors must be discharged. k) Measurements should be taken with dry hands, wearing clothes with sleeves down, rings and metal bracelets should be removed. l) Work in circuits and relay protection devices must be carried out according to the executive diagrams. Working without diagrams, from memory, is prohibited. Before applying operational voltage for setting up and testing circuits of switching devices that are controlled from several places, the possibility of controlling them from other places must be eliminated (circuits are disconnected, posters are posted “Do not turn on. People are working” or “Do not open. People are working”). . When working in the circuits of the secondary windings of voltage transformers with voltage supplied from an external source, the circuit breakers and switches installed in the circuits of the secondary windings of the voltage transformers are turned off in order to avoid reverse transformation to the high voltage side. When working in the circuits of the secondary windings of current transformers and voltage transformers, the following should be taken into account: a) All secondary windings of current and voltage instrument transformers must be permanently grounded. b) It is prohibited to remove the grounding of the secondary windings of current transformers and voltage transformers if they are under operating voltage. It is prohibited to remove the grounding of the metal casings of relay protection and automation devices that are in operation. c) If it is necessary to switch in the circuits of the secondary windings of current transformers when current flows through it primary winding the secondary winding must first be short-circuited at special terminals or at the control plugs of the test blocks. Switching must be done from a dielectric mat. Unscrewing the screws securing the wires should be done slowly, with one hand, without touching either the secondary switching or the panel body with the other hand; if the slightest spark or crack appears, the screw should be immediately screwed back in and the preparatory circuit should be carefully checked again. When the current circuits of measuring current transformers are opened, all work in relay protection and automation devices must be immediately stopped and switching devices in the circuits of the primary windings of these current transformers must be emergency disconnected. d) When checking the polarity of the windings of current transformers with direct current pulses, the measuring device must first be securely connected to the terminals of the secondary winding; only after this can a current pulse be applied to the primary winding. e) Secondary current measurement and protection circuits must be connected to the terminals of the secondary windings of current transformers only after the installation of all circuits has been completed. Personal protective equipment used during work Dielectric gloves. Gloves are designed to protect hands from electric shock. Used when operating in devices up to 1000 V as the main insulating electrical protective agent, and in devices above 1000 V - additional. The length of gloves must be at least 350 mm. The size of dielectric gloves should allow knitted gloves to be worn underneath them to protect hands from low temperatures when working in cold weather. The width along the bottom edge of the gloves should allow them to be pulled over the sleeves of outerwear. Special dielectric footwear (galoshes, boots, including tropical boots) is an additional electrical protective equipment when working in closed or, in the absence of precipitation, in open electrical installations. In addition, dielectric shoes protect workers from step stress. In electrical installations, dielectric boots and galoshes are used, manufactured in accordance with the requirements of state standards. Galoshes are used when working in devices with voltages up to 1000 V, boots - for all voltages. According to their protective properties, shoes are designated as: - galoshes, - bots. Dielectric shoes should be different in color from other rubber shoes. Galoshes and boots must consist of a rubber top, rubber grooved sole, textile lining and internal reinforcing parts. Uniform boots can be produced without lining. Boots must have lapels. The height of the boat must be at least 160 mm. Dielectric rubber carpets. Carpets are manufactured with a thickness of 6±1 mm, a length from 500 to 8000 mm and a width from 500 to 1200 mm. Carpets must have a corrugated front surface and be one color. Covers are used when working in devices up to 20 kV to prevent accidental contact with live parts. In devices up to 1000 V, linings are also used to prevent switches from being switched on incorrectly. Overlays must be made of durable electrical insulating material. The design and dimensions of the linings must allow complete coverage of live parts. In devices above 1000 V, only rigid pads are used. In electrical installations up to 1000 V, flexible dielectric rubber linings can be used to cover live parts during operation without removing voltage. Hand-held insulating tools are used when working in devices up to 1000 V as the main electrical protective equipment. The tool can be of two types: an instrument made entirely of conductive material and covered in whole or in part with electrical insulating material; -
a tool made entirely of electrically insulating material and, if necessary, having metal inserts. Portable grounding connections are designed to protect workers on disconnected live parts of electrical installations from erroneously supplied or induced voltage in the absence of stationary grounding blades. Safety posters and signs are intended for: to prohibit actions with switching devices, if switched on incorrectly, voltage may be supplied to the place of work (prohibition posters); to warn about the danger of approaching live parts that are energized and moving without protective equipment in an outdoor switchgear of 330 kV and higher with an electric field strength higher than permissible (warning signs and posters); to authorize specific actions only if certain safety requirements are met (prescriptive posters); to indicate the location of various objects and devices (directional poster). Posters and safety signs must be made in accordance with the requirements of state standards. Depending on the nature of their application, posters can be permanent or portable, and signs can be permanent. It is recommended that permanent posters and signs be made from electrical insulating materials, and signs on concrete and metal surfaces should be painted using stencils. Portable posters should be made only from electrically insulating materials. The use of permanent posters and signs made of metal is allowed only away from live parts. Conclusion Relay protection automatically eliminates damage and abnormal conditions in the electrical part of power systems and is the most important automation ensuring their reliable and stable operation. In modern energy systems, the importance of relay protection is especially increasing due to the rapid growth in the power of energy systems, their unification into single electrically connected systems within several regions, the entire country, and even several states. Characteristic of modern energy systems is the development of high and ultra-high voltage networks, with the help of which energy systems are interconnected and large flows of electrical energy are transferred from powerful power plants to large consumption centers. Growing loads, increasing the length of power transmission lines, and tightening requirements for the stability of power systems complicate the operating conditions of relay* protection and increase the requirements for its speed, sensitivity and reliability. In this regard, there is a continuous process of development and improvement of relay protection technology, aimed at creating more and more advanced protection that meets the requirements of modern energy. List of used literature 1. Rules for the construction of electrical installations (PUE). Seventh edition. RF. 2. Chernobrovok N.V. Relay protection. Tutorial for technical schools. Ed. 5th, revised and additional M., "Energy", 1974. - 680 p. Handbook for setting up secondary circuits of power plants and substations. A. A. Antushin, A. E. Gomberg, V. P. Karavaev and others; Ed. E. S. Musaelyan. - 2nd ed., revised. and additional - M.: Energoatomizdat, 1989. - 384 p.: ill. Shabad M. A. Calculations of relay protection and automation of distribution networks. - 3rd ed., revised. and additional - L.: Energoatomizdat. Leningr. department, 1985. - 296 p., ill. RD 153-34.0-35.617-2001 "Rules for the maintenance of relay protection devices, electrical automation, remote control and signaling of power plants and substations 110-750 kV." SO 34.35.302-2006 "Standard instructions for the organization and performance of work in relay protection devices and electrical automation of power plants and substations."
Relay protection and automation devices are operated by the local relay protection, automation and electrical measurement services of the MSRPZAI, therefore the OVB personnel inspects the RZAI devices, checks their serviceability and readiness for action at least once a month in the presence of telesignaling about device malfunctions and automatic monitoring of high-frequency channels (if absence, inspections are carried out at least once a week). When visiting a substation for other reasons, the OVB personnel conducts checks of the RZAI devices to the same extent.
When inspecting relay protection, automation and measurement devices, they become familiar with the entries in the relay protection log about all work performed during the period of absence of OVB electricians at the substation, changes in settings, circuits, relay protection devices introduced again or taken out of service, with entries in the operational log . Check the serviceability of the emergency and warning alarms, as well as the switch position alarms, the presence of voltage on the operating current buses, all sources of direct and alternating current and the operating mode under chargers. Monitor the insulation resistance of operational current circuits using stationary devices. Using the alarm system, they check the serviceability of control purposes for switches and other switching devices, the presence of operative current in all devices and circuits of relay protection, automation, alarms, control, the serviceability of fuses and ATS of operative current sources, the correct position of circuit breakers, switches and other switching devices in the ATS circuit and compliance of their provisions with the primary scheme. Using installed measuring instruments and alarms, the serviceability of voltage transformer circuits, fuses, and the correct position of all switching devices in these circuits are monitored in accordance with the actual primary connection diagram.
Inspect all protection and automation devices on the control panel, relay panel, in the corridors of the switchgear, switchgear, checking their serviceability and readiness for action according to appearance or, if possible, by alarm. Indicator relays that were triggered by accidental causes (for example, shocks) are returned to their initial position (state). Check the correct position of all control elements of the relay protection devices and the compliance of their positions with the actual primary circuit of the substation. Inspect and check the serviceability and readiness for operation of fixing instruments, recording measuring instruments and oscilloscopes (they also check the supply of paper and ink for recording instruments, paper or film for oscilloscopes). Inspect gas relays of transformers (for relays with an inspection window, check the housing for the absence of air). Check the position of the drives of switches, disconnectors, separators and short circuiters, seals of doors and covers of relay cabinets, etc.
All faults identified during the inspection are recorded in the relay protection log and immediately reported to the dispatcher of the power plant (RES) and the MSRPZAI personnel.
OVB personnel can eliminate some malfunctions or deviations from the specified mode in relay protection devices. These include:
turning on circuit breakers or replacing fuse links in the circuits of voltage transformers or power supply of relay protection and automation devices (if the switches are repeatedly disconnected or the fuse links burn out, the OVB electrician, senior in the shift, informs the dispatcher and acts on his instructions);
decommissioning of all relay protection devices in the event of a break in the shutdown circuit of a switch or other switching device (the break is detected by an alarm) with subsequent implementation by the dispatcher of the measures provided for the connection that has completely lost relay protection;
decommissioning of all relay protection devices operating from damaged individual power supplies, capacitor chargers and capacitors in the trip circuit of the circuit breaker, separator, short-circuiter, followed by the dispatcher carrying out the measures provided for this connection, which has lost all protections;
determination of the location of damage when a ground fault appears in the operational current circuits (with the permission of the dispatcher, using local instructions);
disabling devices operating on automatic switching on switch, in case of damage to the rectifiers supplying the switching circuits of electromagnetic drives (damage is detected by a decrease in the rectified voltage, measured by a voltmeter, and by external inspection of the rectifiers). When the RZAI devices are triggered, various light and sound alarms operate on the control panel, as well as a remote alarm. By dropping the flags of the indicating relays, the OVB personnel determines which device and which of its zones have been triggered (according to the inscriptions on the relay), after which they carry out the alarm operations prescribed by local instructions (turning off the sound signal, turning on the switch position indicator, etc.). By external inspection and alarm, the OVB personnel identifies the nature of the damage that caused the operation of the relay protection devices, makes an entry in the relay protection log and at the same time informs the dispatcher.
In switching devices that have changed their normal position, acknowledge the control keys in cases where the automatic reclosure and automatic transfer devices did not work successfully. EOD personnel inspect all protection and automation devices and apply marks (for example, with chalk) on the covers of triggered indicating relays or next to them on panels.
At the same time, inspects automatic reclosure and automatic relay counters, recording their readings, as well as recording and recording instruments and oscilloscopes. The results of the inspection, recorded in the relay protection log, are reported to the dispatcher by the OVB personnel and, with his permission, return the indicating relays to their initial state, leaving time stamps until the end of the analysis of the operation of the relay protection devices and receipt of the dispatcher's permission.
After all operations are completed, the position of the indicator relay flags is re-checked (they must be raised), the position of all control elements of the relay protection and protection devices corresponds to the actual primary connection diagram, and the alarm system at the substation is returned to normal. The RZAI service is informed about the operations performed. Upon completion of the analysis of the operation of the relay protection devices, the time stamps on the covers of the indicating relays or panels are erased.
All work on RZAI devices put into operation is, as a rule, performed by MSRZAI personnel based on pre-filled requests. Having received permission from the dispatcher, the EOD personnel prepares the work site: performs the necessary switching on and off of primary equipment, operations with relay protection devices and the requirements of safety regulations; installs fences (curtains) blocking access to neighboring RZAI devices. Having checked the availability of RZAI personnel for the relevant work, he allows them to begin.
OVB personnel, at the request of operating personnel, perform the necessary switching on and off of completely disabled (with disconnectors disconnected) primary switching devices (switches, separators, short circuiters) for various tests and checks of the interaction of relay protection devices with primary equipment. In addition, he receives permission from the dispatcher for the personnel of the RZAI services to perform various switches on and off of energized equipment.
After completion of the work, the OVB personnel familiarize themselves with the entries made by the MSRZAI personnel in the relay protection log, with changes in the equipment on the device panels, carry out the measurements or testing provided for in the instructions, sign in the relay protection log and inform the dispatcher about the completion of the work and the readiness of the relay protection devices for commissioning action.
Operational control of all elements of relay protection, automation and alarm systems is carried out by OVB personnel only with stationary disconnecting devices (control keys, switches, overlays). When taking measurements, he uses only stationary, always-on measuring instruments, self-resetting buttons or other switching devices for short-term measurements (in some cases, local instructions allow the use of portable current clamps, voltmeters, etc.). The operation of various devices is tested by the OVB personnel using certain devices, but does not have the right to turn off and connect wires and cables or use temporary jumpers.
This section presents documentation (standards, rules and instructions) on relay protection and automation (RPA)
This “Instruction for the organization and performance of work in relay protection devices and electrical automation of power plants and substations” (hereinafter referred to as the Instructions) determines the order of organization, methodology and sequence of work during the maintenance of relay protection devices and electrical automation of power plants and substations.
With the release of this Instruction, the “Standard Instructions for the organization and performance of work in relay protection devices and electrical automation of power plants and substations” (M: SPO ORGRES, 1991) becomes invalid.
Time standards for maintenance of IC-based relay protection devices are recommended for use at the enterprises of the Ministry of Fuel and Energy. Time standards are given in man-hours and are set for the full scope of work provided for by their content and to be performed by the team of performers. The content of maintenance work on relay protection devices includes basic operations; in most cases, minor operations are not indicated, but are taken into account by time standards. When work is performed by a unit, labor costs are distributed equally between performers for all types of maintenance.
Calculation of effective current values short circuit(short-circuit) in networks with a voltage of 3000 (3300) V is carried out in order to determine the maximum value of the three-phase short circuit current required to test switching equipment for breaking capacity and cables for thermal resistance, as well as the minimum value of the two-phase short circuit current required for checking the settings of protective equipment.
These Standards apply to relay protection devices in the automation of thermal power plants and include consumption standards for Western relays and spare parts for them to restore the working condition of relay equipment.
The standards are drawn up for relays of mass use, as well as for protective circuit breakers AP-50, control keys, test units and switching devices.
When drawing up the Standards, data from questionnaires were used, as well as the results of a survey of a number of power plants and energy systems.
The standards are intended for use in preparing annual applications for spare relays and spare parts for them.
Temporarily, until special standards are developed, these Standards can also be used for relay protection equipment and substation automation.
These Standards for the consumption of spare relays and spare parts apply to relay protection devices, electrical automation and emergency automatic equipment (hereinafter referred to as RPA devices) of enterprises of electrical networks and substations with a voltage of 35 kV and above the Ministry of Energy of the USSR and establish the annual consumption standards for spare panels, protection relays and electrical automatic equipment, equipment remote control and spare parts for them for repair and maintenance needs for:
failure of relay protection and automation devices during operation or detected during scheduled maintenance;
carrying out reconstructions according to the instructions of the Main Technical Directorate, feasibility study, POEE;
replacement of worn-out and discontinued relay protection devices.
The standards are intended for personnel of relay protection and electrical automation services of electrical network enterprises, when drawing up annual applications for spare relays and spare parts for them.
Temporarily, until special standards are developed, the standards indicated in Table. 4-6, can be used in electrical networks with voltages below 35 kV.
This instruction is compiled on the basis of “Guidelines for setting up, testing and operating the relay part of differential-phase high-frequency protection type DFZ-2”, Gosenergoizdat, 1957 (authors V.V. Kochetov, E.D. Sapir, G.G. Yakubson) . A number of additions and clarifications have been made to the used text of the Guidelines, providing for a reduction in the scope of checks and simplification of test methods, based on operating experience. These simplifications do not introduce fundamental changes to the fundamentals of the test methodology laid down in the above-mentioned Guidelines.
Additionally, descriptions are also given of typical options for implementing protection on lines with branches and instructions for checking it, technical data and instructions on the features of testing the protection of a single-ampere version of protection type DFZ-2/1.
The instructions for setting up and testing are linked to directive materials * (regarding the types, scope and timing of testing), with the “General Instructions for Testing Relay Protection Devices, Electrical Automatics and Secondary Circuits” (Gosenergoizdat, 1961) and with other instructions for testing devices and individual relay protection elements. In order to make this connection, some instructions for checking individual elements of the DFZ-2 protection have been replaced with links to these instructions.
Taking into account the equipment of power systems with relay protection devices, electrical automation and emergency automatic equipment (RPA), as well as accounting, analysis and evaluation of their operation make it possible to:
assess the compliance of relay protection and automation devices with the requirements, their reliability and suitability for operation;
identify characteristic causes of their incorrect operations and failures to operate in order to develop organizational and technical measures to improve the operation of relay protection and automation devices, make claims to design, installation, commissioning organizations, development organizations and supplier plants;
identify and eliminate deficiencies in the implementation and operation of these devices;
determine the main operational indicators of individual types of relay protection and automation (percentage proper operation, the success of automatic reclosing and automatic transfer systems, the frequency or frequency of operation of relay protection and automation devices, etc.) and assess the number and load indicators of the personnel of relay protection and automation services of electrical network enterprises and ETL power plants (hereinafter referred to as the relay protection service service).
THIS DOCUMENT HAS BEEN DEVELOPED BY:
State Institute for Design and Research in the Oil Industry "Giprovostokneft"
Director of the Institute B.P. Usachev September 8, 1988
Head of the Electric Power Supply Reliability Department I.V. Christov September 8, 1988
Head of Sector A.T. Subochev September 8, 1988
AGREED:
Head of the Department for Operation of Power-Mechanical Equipment V.A. Romanov September 15, 1988
INSTEAD RD 39-0148311-601-85 "Regulations on the system of maintenance and repair of electrical installations in oil production and drilling"
The provision includes:
Part 1. General provisions. Electrical equipment and power lines;
Part 2. Relay protection and automation devices. Prevention trials. Electrical measuring instruments.
This Standard Regulation applies to relay protection and electrical automation services at all levels of management of the Russian electric power industry. The standard provision is the basis for drawing up local regulations on the relay protection and electrical automation services of the central control department of the UES of Russia, the integrated control system of integrated systems (UPS), intersystem electric networks (IES), regional energos, power plants, cascades of hydroelectric power plants, electric grid enterprises, MES enterprises (PMES) .
The Standard Regulations reflect issues of organizational and technical maintenance of relay protection devices, electrical automation, remote control and alarm systems.
With the release of this Model Regulation, the “Standard Regulations on Relay Protection and Electrical Automation Services” (M.: SPO Soyuztekhenergo, 1981) and the “Standard Regulations on the Relay Protection and Electrical Automation Service PEO: RD 34.04.418-88” (M.: Management) become invalid labor and wages Ministry of Energy of the USSR, 1988).
The current local regulations, during their next revision, must be brought into line with this Model Regulation, taking into account the existing organizational structure and relationships between departments.
The instructions contain instructions for checking current transformers (CTs) used for relay protection, automation and measurement, as well as instructions for checking secondary current circuits up to the input terminals of protection, automation and measurement devices.
Checking the current circuits inside the specified devices, as well as checking the CT in the complete circuit of the device, must be carried out in accordance with the standard instructions for organizing and performing work on relay protection and electrical automation devices of power plants and substations.
When preparing the third edition, comments from a number of power systems to the previous edition of the Instructions and changes that have appeared over time in electrical engineering, organization and energy economics were taken into account.
This edition of the Instructions includes a section on methods for checking CT errors for different options for their use in relay protection, which lists the currently existing methods for determining CT errors and provides a brief summary of the two simplest of them.
These Rules are mandatory for workers involved in setting up and operating relay protection and electrical automation devices (RPA) at the enterprises of Intersystem Electric Networks (IES) and JSC-Energo, at power plants of RAO "UES of Russia".
The rules determine the types, frequency, programs and volumes of maintenance of relay protection and automation devices, remote control and signaling devices (hereinafter referred to as relay protection devices), high-frequency relay protection channels, current and voltage transformers.
These Recommendations are intended to assist power systems in the reconstruction and replacement of relay protection and automation devices that have exhausted their service life or are obsolete. Specialists from OJSC “CHEAZ” G.P. took part in the development of the Recommendations. Varganov, A..A. Klimov and R.Z. Rosenblum, materials from the report of K.M. were partially used. Dobrodeeva (Nizhegorodskenergosetproekt) at a meeting of the management personnel of the relay protection and automation services of the power systems of the UES of the Middle Volga and MES of the Volga in October 1999, as well as reviews from a number of organizations on the first edition of the Recommendations.
These Rules are mandatory for workers involved in setting up and operating relay protection and electrical automation devices (RPA) of 0.4-35 kV electrical networks in the power systems of the Russian Federation.
The rules determine the types, frequency, programs and volumes of maintenance of relay protection and automation devices, current and voltage transformers, power supplies and other relay protection and automation devices used in 0.4-35 kV electrical networks.
WITH
With the release of these Rules, the previously existing “Rules for the maintenance of relay protection devices and electrical automation of electrical networks of 0.4-35 kV: RD 34.35.613-89” (M.: SPO Soyuztekhenergo, 1989) are considered no longer in force.
These Rules apply to relay protection and automation devices installed at nuclear power plants (NPs) in electrical installations for power delivery and auxiliary networks for controlling electrical equipment, as well as for relay protection and fault signaling. These relay protection and automation devices include low-voltage complete devices (panels, cabinets, units and consoles installed in them), associated auxiliary control and measurement circuits (current circuits and voltage circuits from instrument transformers.
This “Standard Regulations on the Relay Protection and Electrical Automation Service of Nuclear Power Plants” (hereinafter referred to as the Standard Regulations) establishes the main tasks and functions of the Relay Protection and Automation Service (hereinafter referred to as the Relay Protection and Automation Service) in the systems of operation, maintenance and repair of nuclear power plants (hereinafter referred to as the AS) and is the basis for the development of plant regulations on the relay protection and automation service of a nuclear power plant.
This guidance document of the operating organization (hereinafter referred to as RD) establishes the minimum technical requirements to relay protection and automation devices for electrical installations of nuclear power plants. The requirements of this RD must be applied when replacing relay protection and automation devices put into operation according to the original design.
This RD applies to systems and devices:
- relay protection of electrical equipment of the NPP auxiliary network (normal operation systems and emergency power supply systems for auxiliary needs (EPS));
- devices automatic input reserve (AVR) of electrical and technological equipment of nuclear power plants.
The requirements of this RD must be met by all divisions of Rosenergoatom Concern OJSC when developing design estimates for the replacement of relay protection and automation devices (RPA), when carrying out procedures for selecting manufacturers and (or) suppliers of hardware and software for relay protection devices and automation (URZA), as well as in the technical specifications of the contract for production and (or) supply.
This guidance document of the operating organization (hereinafter referred to as RD) establishes the minimum technical requirements for relay protection and automation devices of nuclear power plant electrical installations. This RD is intended for use when replacing relay protection and electrical automation devices put into operation according to the original design.
This “Instruction for operating personnel for servicing relay protection devices and electrical automation of power systems” (hereinafter referred to as the Instructions) defines the rights and responsibilities of operating personnel and contains general instructions for the operational management and maintenance of relay protection and automation devices, monitoring their serviceability and eliminating a number of malfunctions, and organizing work in these devices, as well as by the actions of operating personnel when they are triggered.
The Guidelines contain recommendations on the required volumes, methods and duration of characterization of turbogenerator-transformer units and their relay protection and automation devices when conducting complex electrical tests.
The guidelines are intended for the personnel of commissioning organizations and operational personnel involved in testing electrical equipment and relay protection and automation devices before connecting units being put into operation into the network and after completing major repairs.
This collection contains departmental aggregated unit prices for the maintenance of relay protection and automation devices (circuit breakers, relays, protection kits, interlocking devices).
The prices are intended for planning work and drawing up estimates for the maintenance of the specified relay protection and automation devices, performed by personnel of power grid operating and repair enterprises in a market economy, and are advisory in nature. The information in the collection is sufficient to formulate standardized tasks for teams.
The standard establishes principles for organizing interaction between relay protection and automation services (divisions) when they perform functions for centralized management of relay protection systems and devices in a hierarchical management structure and when they perform functions for non-centralized management of relay protection systems and devices in the economic structure of management and operation of relay protection and automation devices installed at power plants and substations of the subjects of the electric power industry of the UES of Russia, as well as subjects of technologically isolated regional energy systems.
Standard time standards for major renovation low-voltage electrical ballasts, relay protection and automation equipment are recommended for use in electromechanical workshops, enterprise sites and specialized repair shops in sectors of the national economy, regardless of their departmental subordination.
Time standards are intended to regulate the work of electricians in repairing electrical equipment under piecework and time-based wage systems.
General requirements for systems of emergency and operational automation, relay protection and automation, telemetric information and technological communication in the UES of Russia (hereinafter referred to as the General Requirements) are intended to ensure the requirements of a unified technical policy in the subsidiaries and dependent companies of OAO RAO UES of Russia during the design, reconstruction and construction of new energy facilities in the Unified Energy System of Russia.