a) Polarity of all windings;

b) Transformation ratios of all windings and their taps;

c) The accuracy level of the voltage transformer under each usage capacity;

d) The accuracy level (level), capacity and internal installation position of each winding of the current transformer;

e) DC resistance of the secondary winding (each tap);

f) Volt-ampere characteristics of each winding of the current transformer.

6.1.2.1 The transformation ratio, capacity and accuracy level of current and voltage transformers must meet the design requirements.

6.1.2.2 Test the polarity relationship between the windings of the transformer and check whether the polarity markings on the nameplate are correct. Check whether the connection method of each winding of the transformer and its polarity relationship are consistent with the design, and whether the phase identification is correct.

6.1.2.3 When possible, flow current from the primary phase of the current transformer, and check whether the transformation ratio of the working tap and the circuit are correct (the polarity of the external transformer and transformer bushing transformer used for generator and transformer unit protection The transformation ratio inspection can be carried out during the short circuit test of the generator).

6.1.2.4 Pass AC current from the secondary terminal box of the current transformer to the load end, measure the voltage drop of the loop, and calculate the impedance (secondary loop burden) between each phase of the current loop and the neutral line and between phases. Use the measured impedance value to check whether it meets the 10% error requirement of the transformer according to the specific working conditions of the protection and the factory data provided by the manufacturer.

a) Check the correctness of all secondary wiring of the current transformer secondary winding and the reliability of the crimping of the terminal block lead screws.

b) Check the grounding point and grounding condition of the current secondary circuit. The secondary circuits of the current transformers must be grounded separately and at only one point; the current circuit composed of several groups of secondary current transformers should be connected at a direct electrical connection A little grounding.

6.2.3.1 Check the correctness of all secondary circuit wiring of the secondary and tertiary windings of the voltage transformer and the reliability of the crimping of the terminal block lead screws

6.2.3.2 For several groups of secondary circuits of voltage transformers connected through the small neutral busbar (N600) in the control room, only N600 should be grounded at one point in the control room, and the secondary neutral point of each voltage transformer should be at the grounding point of the switching field. should be disconnected; in order to ensure reliable grounding, the neutral wire of each voltage transformer must not be connected to a fuse (automatic switch) or contactor that may be disconnected. An independent secondary circuit that has no direct electrical connection with other transformer secondary circuits can be grounded at one point in the control room or in the switching field. The 4 switching field lead-in wires from the secondary circuit of the voltage transformer and the 2 (3) switching field lead-in wires from the tertiary circuit of the transformer must be separated and must not be shared.

6.2.3.3 Check whether the installation of the metal oxide arrester with the secondary neutral point of the voltage transformer in the switching field complies with regulations.

6.2.3.4 Check the installation location of all fuses (automatic switches) in the secondary circuit of the voltage transformer, whether the fusing (tripping) current is appropriate (the tripping current of the automatic switch needs to be determined through testing), whether the quality is good, and whether To ensure selectivity, the automatic switch coil impedance value is appropriate.

6.2.3.5 Check the reliability of the contacts of fuses (automatic switches), isolation switches and switching equipment connected in series in the voltage circuit.

6.2.3.6 Measure the DC resistance of each phase of the voltage loop from the transformer lead-out terminal to the voltage busbar of the distribution panel, and calculate the voltage drop of the voltage transformer under rated capacity. Its value should not exceed 3% of the rated voltage.

Before performing an insulation check on the secondary circuit, it must be confirmed that all circuit breakers and current transformers of the protected equipment are out of power, the AC voltage circuit has been disconnected from other circuits at the voltage switching handle or junction box, and is well isolated from other circuits. Only after that is allowed to proceed.

6.2.4.1 When conducting the acceptance test of the newly installed device, disconnect all externally introduced loops and cables from the terminal block of the protection panel cabinet, and connect all terminals of the current, voltage, DC control, and signal loops together respectively. Use a 1000V megohmmeter to measure the insulation resistance. The circuit whose resistance value should be greater than 10MΩ is as follows:

6.2.4.2 During periodic inspection, disassemble the external wiring of all current, voltage, and DC control loop terminals at the terminal block of the protection panel cabinet, disassemble the grounding points of the voltage and current loops, and measure with a 1000V megger. The insulation resistance of the loop to the ground should be greater than 1MΩ.

6.2.4.3 For signal circuits using contact output, use a 1000V megohmmeter to measure the insulation resistance of each core of the cable to the ground and to other cores. The insulation resistance should not be less than 1MΩ. Periodic inspections only measure the insulation resistance of core wires to ground.

6.2.4.4 For the secondary circuit of a voltage transformer that uses a metal oxide arrester for grounding, it is necessary to check the correctness of its wiring and the power frequency discharge voltage of the metal oxide arrester.

a) Observe, clean and perform necessary maintenance and adjustments on all components of the circuit. The components include: operating handles, buttons, plugs, lamp holders, position indicating relays, central signaling devices related to the device, and terminal strips, cables, fuses, etc. in the circuits of these components.

b) Use the conduction method to pass through all the intermediate terminals in sequence, check the cable loops and cable core labels from the transformer terminal box to the operation panel cabinet, protection panel cabinet, automatic device panel cabinet or to the distribution box, and check the cable Are the entries in the booklet correct?

c) When equipment is newly put into operation or connected to a new circuit, check whether the rated current of the fuse (and automatic switch) is consistent with the design or adapted to the connected load, and the coordination between the upper and lower levels is met.

d) Check that the equipment on the panel cabinet and the internal and external connections on the terminal strips should be correctly wired, the contacts should be secure, the labels should be complete and accurate, and they should be consistent with the drawings and operating procedures. Check that cable terminals and cable labels along the cable laying route are correct, complete and consistent with the design.

e) Verify that there is indeed no parasitic loop in the DC loop. During the inspection, the inspection should be based on the specific conditions of the circuit design, by separately disconnecting some equipment in the circuit that may be disconnected during operation (such as fuses, indicator lights, etc.) and by closing some contacts in the circuit. Each independent device should have a dedicated terminal pair dedicated to the positive and negative power supply directly to the DC fuse. All DC circuits protected by this set, including the coil circuit of the trip outlet relay, must and can only be connected from this Obtain DC positive and negative power from the dedicated terminals.

f) Signal circuits and equipment do not need to be individually inspected.

a) All adjustment and testing work on circuit breakers and isolating switches related to the secondary circuit of the device shall be carried out by the relevant personnel in charge of circuit breakers and isolating switches. Relay protection inspection personnel should understand the technical performance of the relevant equipment and its debugging results, and be responsible for inspecting the correctness of the cable connections and screw compression at the secondary circuit terminal block from the protection panel to the circuit breaker (including the isolating switch). The reliability of the connection.

b) Relay protection personnel should also understand the following:

a) Plug-ins are allowed to be inserted and removed only after the power supply to the protection device is disconnected, and measures must be taken to prevent damage to the plug-ins due to static electricity.

b) If there is a problem during debugging, find the cause first and do not replace the chip frequently. When the chip must be replaced, a special puller must be used. Pay attention to the direction of chip insertion. After inserting the chip, it must be checked by a second person before it can be powered on for inspection or use.

c) Try not to use a soldering iron during inspection. If components are damaged and must be welded on site, use an internally heated soldering iron with a grounding wire or turn off the power to the soldering iron before welding. Replaced components must be qualified products confirmed by the manufacturer.

d) When using electronic instruments with AC power supply (such as oscilloscopes, frequency meters, etc.) to measure circuit parameters, the measurement terminals of the electronic instrument must be well insulated from the power supply side, and the instrument shell should be grounded at the same point as the protective device.

a) The actual composition of the device, such as: device configuration, device model, rated parameters (DC power supply rated voltage, AC rated current, voltage, etc.) are consistent with the design.

b) The workmanship quality of main equipment and auxiliary equipment, as well as the quality of materials used for wires and terminals. All welding points inside the device, the reliability of plug-in contacts, etc. are issues related to the quality of the manufacturing process, and the manufacturer is mainly responsible for ensuring product quality. When inspecting newly installed devices, test personnel only conduct random checks.

c) The signs on the screen cabinet should be correct, complete and clear, and consistent with the drawings and operating procedures.

d) Check that the electromagnetic interference mitigation devices and measures installed in the device input loop and power loop should comply with relevant standards and the manufacturer's technical requirements. These electromagnetic interference mitigation devices and measures should be kept in good condition during the entire process of device inspection.

e) The connecting pieces on the protective screen cabinet that do not participate in normal operation should be removed, or other measures should be taken to prevent mis-throwing.

f) Main inspection items for periodic inspection:

a) Insulation tests are only carried out during the acceptance inspection of newly installed installations.

b) Pull out the plug-in according to the requirements of the device technical manual.

c) Short-circuit the AC voltage loop terminals, AC current loop terminals, DC power loop terminals, tripping and closing loop terminals, digital input loop terminals, factory automation system interface loop terminals and signal loop terminals on the inside of the terminal block of the protection panel cabinet. .

d) Disconnect the weak current connection loop with other protections.

e) Disconnect the printer from the device.

f) The shielding layers of all transformers in the device should be reliably grounded. When measuring the insulation resistance of a certain group of circuits to ground, all other groups of circuits should be grounded.

g) Use a 500V megohmmeter to measure the insulation resistance value. The resistance values ​​must be greater than 20MΩ. After testing, each circuit should be discharged to ground. 6.3.4 Power-on inspection:

a) Turn on the power of the device and the device should work normally.

b) Check and record the hardware and software version numbers, check codes and other information of the device according to the method described in the device technical manual.

c) Calibrate the clock.

6.3.5.1 For microcomputer type devices, all plug-ins are required to be inserted.

6.3.5.2 When there are testing conditions, the output voltage values ​​of each stage of the inverter power supply should be measured, and the measurement results should comply with DL/T527-2002. During periodic inspections, only the values ​​of the output voltage of each stage at the rated voltage are measured. If necessary, the values ​​of the output voltage of the external DC power supply at each stage of the protected power supply at the highest and lowest voltages are measured.

6.3.5.3 It is recommended to use the following method to test the self-starting performance when the DC power supply rises slowly: close the power switch on the inverter power plug-in of the device, and test the DC power supply to slowly rise from zero to 80% of the rated voltage. At this time, the inverter power plug-in The power light on the panel should be on. Fix the test DC power supply to 80% of the rated voltage, close the DC switch, and the inverter power supply should start reliably.

6.3.5.4 During periodic inspections, it should also be checked whether the inverter power supply has reached the service life specified in DL/T 527-2002.

a) During acceptance inspection of newly installed devices:

b) During all inspections, only add excitation quantities to the six switching input circuits that have been put into use, and observe the behavior of the device.

c) Partial inspection can be carried out together with the entire set of shower inspections of the device.

a) During the acceptance inspection of a newly installed device: At the terminal block of the device panel cabinet, follow the test methods specified in the device technical instructions and observe the on-off status of all output signals of the device in sequence.

b) During all inspections, observe the on-off status of the output contacts and long output signals of the device that have been put into use at the terminal block of the device inspection cabinet in accordance with the test methods specified in the device technical instructions.

c) During partial inspection, the entire set of tests accompanying the device shall be conducted together.

a) Check the zero drift. This inspection requires that the device does not input AC current and voltage values. Observe that the zero drift value of the device within a period of time meets the requirements.

b) Amplitude and phase accuracy inspection of each current and voltage input

a) Each set of protection should be inspected individually. The AC and DC power supplies and time measurement connections in the test wiring circuit should be directly connected to the terminal strip of the protection panel cabinet under test. The relative polarity relationship of the AC voltage and current test wiring should be completely consistent with the relative phase nature (phase relationship converted to the primary side) of the voltage and current transformers connected to the panel cabinet in the actual operating wiring.

b) During the setting inspection, except that the AC current and voltage passed through are simulated fault values ​​and the tripping and closing circuits of the circuit breaker are disconnected, the entire device should be under conditions that are completely consistent with the actual operating conditions and must not be Artificial changes were made during the experiment.

c) The action time of the device setting is the entire time from the input of simulated fault components (current, voltage or current and voltage) to the protection panel cabinet until the protection action sends a tripping pulse to the circuit breaker.

d) The inspection items and content of electrical characteristics should be formulated based on the nature of the inspection, the specific construction method and operating principle of the device. When testing the characteristics of the device, it should in principle conform to the actual operating conditions and meet the requirements of actual operation. Each inspection item should have a clear purpose, either necessary for operation, or used to determine whether components and devices are in good condition and to discover possible defects, etc.

a) During the acceptance inspection of a newly installed device, each functional component of the protection should be inspected one by one according to the setting items on the setting notice and in accordance with the device technical specifications or the test methods recommended by the manufacturer.

b) During all inspections, only one of the protective elements composed of different principles needs to be selected for inspection. It is recommended to check the setting items of the main protection. For backup protection such as phase-to-phase I, II, and III section impedance protection, you only need to select any setting item for inspection.

c) Partial inspection can be carried out in conjunction with the entire set of tests of the device.

a) The test items of wave arresters, combination filters, high-frequency cables and other equipment in the dedicated relay protection carrier channel are consistent with those specified for power line carrier communications. The communication department is responsible for the test work of channels shared with communications. In addition to meeting the requirements of communication itself, the entire set of test characteristics of the channel should also meet the relevant requirements for the safe operation of relay protection. During all inspections, only tests related to filters and high-frequency cables are conducted.

b) Put in the grounding switch of the combined equipment, disconnect the primary (high voltage) side of the combined equipment, and remove the grounding point. Use a 1000V megger to measure the secondary side (including high-frequency cable) and primary side of the combined filter respectively. The insulation resistance from side to ground and the insulation resistance between primary and secondary.

c) Measure the carrier channel transmission loss. During partial inspection, the method of measuring the reception level can be simply replaced (the opposite side transmitter sends a continuous high-frequency signal with full power), and the reception level is compared with the reception level measured in the latest channel transmission attenuation test. When compared with the normal phase, if the difference is greater than 3dB, the cause of the change in channel transmission loss value must be further examined.

d) For a dedicated transceiver, after it is newly put into operation and after individual equipment is replaced (added or removed) in the channel, the results of the transmission attenuation test should ensure that the channel margin is sufficient when the receiver receives the signal from the opposite end. The amount is not less than 8.686dB, otherwise the protection is not allowed to be put into operation.

a) For optical fiber and microwave channels, a self-loop method can be used to check whether the optical fiber channel is intact.

b) For protective accessory interface equipment connected to optical fiber and microwave channels, the grounding conditions of the relay output contacts, power supply and interface equipment should be checked.

c) Communications majors should check the bit error rate and transmission time of optical fiber and microwave channels, and the indicators should meet the requirements of GB/T14285.

d) For remote transmission equipment that uses dedicated optical fiber and microwave channels to transmit protection information, its transmitting level and receiving sensitivity level should be tested, and the channel margin should be ensured to meet operational requirements.

a) When conducting each test, test personnel must prepare a detailed test plan to minimize the number of circuit breaker operations. b) For split-phase operating circuit breakers, phase-by-phase transmission should be used to prevent the circuit breaker from jumping the circuit.

c) For the outlet relay in the operation box, the operating voltage range should also be inspected, and its value should be between 55% and 70% of the rated voltage. For relays in other logic circuits, they should operate reliably at 80% of the rated voltage.

a) Prevent circuit breaker jump circuits and three-phase inconsistent circuits. If the circuit breaker jump prevention circuit and the three-phase inconsistent circuit of the circuit breaker body are used, check whether the relevant circuits of the operation box meet the operation requirements.

b) Switching circuit for AC voltage.

c) The wiring of the closing circuit, trip 1 circuit and trip 2 circuit is correct, and ensure that there are no parasitic circuits between each circuit.

a) The circuit breaker opens and closes on the spot.

b) Remote opening and closing transmission of circuit breaker.

c) Prevent circuit breaker from jumping the circuit transmission.

d) The three-phase circuit breaker is inconsistent with the circuit drive.

e) Check the circuit breaker operation blocking function.

f) Inspection of circuit breaker operating oil pressure or air pressure relays, SF₆ density relays and spring pressure contacts. Check whether the pressure relay contact outputs at all levels are correct. Check whether the low-pressure locking closing, locking reclosing, locking trip and other functions are correct.

g) Circuit breaker auxiliary contact inspection, remote and local mode function inspection.

h) When using the circuit breaker jump prevention circuit of the operation box, the self-holding coil connected in series to the tripping and closing circuit should be checked. Its operating current should not be greater than 50% of the rated tripping and closing current, and the coil voltage drop should be less than the rated value. 5%.

i) All circuit breaker signals checked.

a) During the entire set of tests, the coordination between the protections, device action behavior, circuit breaker action behavior, protection starting fault recording signal, dispatch automation system signal, central signal, monitoring information, etc. should be checked for accuracy.

b) The entire set of tests for longitudinal protection, remote tripping, etc. implemented with the help of transmission channels should be carried out together with the inspection of the transmission channels. If necessary, tests can be conducted in conjunction with the corresponding protection on the opposite side of the line to simulate the protection action behavior during faults within and outside the area.

c) For lines equipped with comprehensive reclosing devices, the interaction between the protection and reclosing devices should be checked to be consistent with the design.

In order to reduce the number of tripping times of the circuit breaker, a simulated circuit breaker should be used instead of the actual circuit breaker during the test. When using a simulated circuit breaker, it should be connected from the outlet of the operation box and form a closed loop with the device and tester.

d) Connect the device and reclosing device to the actual circuit breaker circuit, and conduct necessary tripping and closing tests to check the relevant tripping and closing circuits, the circuit breaker jump prevention circuit, the reclosing deactivation circuit and the gas ( Hydraulic lockout and other related circuit operations are correct. Check whether the current, voltage of each phase and the phase of the circuit breaker tripping and closing circuit are consistent.

e) When conducting the entire set of tests, it should also be checked that the voltage drop of the circuit breaker and closing coil is not less than 90% of the rated value.

During periodic inspections, the continuity method is allowed to confirm the correctness of the wiring of each circuit breaker. Under normal circumstances, the correctness of the circuit design and wiring of bus differential protection, failure protection and power grid safety automatic devices must be based on each inspection result (especially the polarity relationship of the current transformer) and the interaction inspection results of the protection itself to judge.

If the substation expansion transformer, line or circuit changes, bus differential protection, failure protection and grid safety automatic device should be used to transmit to the circuit breaker if possible.

a) Whether the phase and polarity of the voltage and current circuits between each set of protection are consistent.

b) Under the same type of fault, whether the protections that should operate at the same time and send out tripping pulses can operate in simulated short-circuit faults, and whether their signal indications are correct.

c) Whether the polarity connection of the DC relay with more than two coils is correct, and whether the operation (or holding) performance of the circuit that uses current to start (or hold) is reliable.

d) Whether the performance of all loops that have a closed relationship with each other is consistent with the design.

e) Whether the names and position numbers of all handles and connecting pieces that need to be operated by the attendant during operation are correct, and whether they are consistent with the names and usage conditions of the equipment during operation.

f) The central signaling device and related optical and audio signal instructions are accurate.

g) Whether there are parasitic loops in each set of protection under normal and abnormal conditions of the true flow source (opening a new set of protection from the terminal row, single negative power supply, etc.).

h) The reliability of the circuit breaker tripping circuit, in which a single-phase overlapping line is installed, and the voltage, current, and circuit breaker circuit phase are verified to be correct. sex. For circuit breakers with double trip coils, the poles of the two trip wirings should be set steadily.

i) Whether the automatic overlap cycle can ensure that multiple overlaps occur according to the prescribed dynamic calculation solution.