Method for online replacement of faulty components and transmission inspection protection of bus differential protection device

Abstract

The invention discloses a method for online replacement of faulty components and transmission inspection protection of a bus differential protection device, the method comprising: preliminarily checking a bus differential protection device to determine whether a preliminary inspection result of the bus differential protection device meets a test condition; if so, backing up parameters of the bus differential protection device; preliminarily testing a bus differential screen vector of the bus differential protection device to determine whether a preliminary test result of the bus differential screen vector is qualified; if so, performing an online replacement operation on the faulty component of the bus differential protection device; rechecking the bus differential protection device to determine whether a secondary inspection result of the bus differential protection device meets a debugging condition; if so, debugging the bus differential protection device and performing a primary recovery operation on the bus differential protection device; retesting the bus differential screen vector of the bus differential protection device to determine whether a secondary test result of the bus differential screen vector is qualified; if the secondary test result of the bus differential screen vector is qualified, performing a secondary recovery operation on the bus differential protection device.

Description

Technical Field

[0001] The invention relates to the field of relay protection of power systems, and in particular to a method for online replacement of faulty components and transmission inspection protection of a bus differential protection device. Background Art

[0002] In the power system, the busbar connects the various current-carrying branch circuits in the distribution device, plays the role of collecting, distributing and transmitting electric energy, and is the main conductor used by power plants or substations to transmit electric energy. When a busbar fails, not only will all the intervals connected to the faulty busbar be cut off, but in serious cases, it will even destroy the stability of the entire power grid, expand the accident, and have very serious consequences. For this reason, busbar differential protection is installed on the busbar, which can quickly cut off the faulty busbar, ensure the normal operation of the non-faulty busbar, and reduce the power outage loss and the scope of the fault.

[0003] When the faulty component of the bus differential protection device needs to be replaced, the substation adopts a dual-bus dual-section wiring structure, and the two sections of the bus cannot be shut down at the same time. If the faulty component is replaced directly, it will cause the bus differential protection device to malfunction, causing a large-scale power outage. If the power supply load of the bus protected by the faulty bus differential protection device is transferred to other buses, the corresponding bus is shut down, and the faulty component of the bus differential protection device and the transmission inspection protection device are replaced, the substation duty personnel will have a long time to perform the switching operation, and the remaining two transformers in the station will be seriously overloaded, the transformer operation loss will increase significantly, destroying the existing economic operation status, and the equipment operation condition will be greatly deteriorated.

[0004] At present, other domestic power companies have summarized and refined some methods of short-time live transmission of bus differential protection devices to check the secondary circuit of bus differential protection, such as the "Method of short-time live transmission to check the secondary circuit of bus differential protection" disclosed in Chinese patent document 201710461893.3, which includes checking whether there is an alarm signal of the bus differential protection device, whether it is in the startup state, whether the input, function pressure plate, analog quantity, fixed value, and output pressure plate of the protection device are normal, and if there is an abnormality, maintenance personnel need to handle it. If there is no abnormality in the bus differential protection device, use the short-time live transmission menu to instantly drive a branch circuit breaker, and check whether the circuit breaker trips normally. This solution does not need to shut down the protected bus. The function pressure plate of the bus differential protection, the input and output circuits are still connected normally, and the current and voltage are collected in real time. If a fault occurs in the bus area, the bus differential protection can operate correctly. However, this technical solution requires the circuit breaker to be driven to be transferred from the operating state to the maintenance state before the circuit breaker can be driven. It is necessary to formulate a power outage plan for the circuit breaker to be driven in advance to complete the corresponding power supply load transfer, which is greatly affected by the system operation mode. This solution can only verify the output circuit of the bus differential protection device, and cannot verify whether the judgment logic of the protection CPU and the locking CPU is correct, which has certain limitations. Summary of the invention

[0005] In order to overcome the problem that the replacement of faulty components and transmission inspection protection of a bus differential protection device requires all protected bus and feeder line intervals to be shut down, or the power supply load transfer causes serious overload of other power supply equipment and shortens the normal operating life of the equipment, the present invention proposes a method for online replacement of faulty components and transmission inspection protection of a bus differential protection device.

[0006] The present invention proposes a method for online replacement of faulty components and transmission inspection protection of a bus differential protection device, comprising the following steps: preliminarily checking the bus differential protection device to determine whether the preliminary inspection result of the bus differential protection device meets the test conditions; if the preliminary inspection result of the bus differential protection device meets the test conditions, backing up the parameters of the bus differential protection device; preliminarily testing the bus differential screen vector of the bus differential protection device to determine whether the preliminary test result of the bus differential screen vector is qualified; if the preliminary test result of the bus differential screen vector is qualified, performing an online replacement operation on the faulty component of the bus differential protection device; rechecking the bus differential protection device to determine whether the secondary inspection result of the bus differential protection device meets the debugging conditions; if so, debugging the bus differential protection device and performing a primary recovery operation on the bus differential protection device; retesting the bus differential screen vector of the bus differential protection device to determine whether the secondary test result of the bus differential screen vector is qualified; if the secondary test result of the bus differential screen vector is qualified, performing a secondary recovery operation on the bus differential protection device.

[0007] Furthermore, the test condition is that the bus differential protection device has no other alarm signals except the alarm signal of the protection CPU board, and there is no out-of-zone fault or power system disturbance in the bus portion of the bus differential protection device.

[0008] Furthermore, the step of preliminary checking the busbar protection device includes: checking the alarm signal of the busbar protection device to determine whether the busbar protection device has other alarm signals besides the alarm signal of the protection CPU board; detecting whether the busbar of the busbar protection device has an out-of-zone fault or a power system disturbance; if the busbar protection device has no other alarm signals besides the alarm signal of the protection CPU board, and the busbar part of the bus differential protection device does not have an out-of-zone fault or a power system disturbance, then the bus differential protection device meets the test conditions; otherwise, it does not meet the test conditions.

[0009] Furthermore, the bus differential protection device parameters include bus differential protection device system parameters, protection settings, bus and interval settings.

[0010] Furthermore, the bus differential screen vector of the bus differential protection device includes the small differential current, large differential current, voltage amplitude and phase of the dual busbars of the bus differential protection device; if the small differential current and large differential current of the dual busbars approach 0, the voltage amplitude is balanced, the voltage phase satisfies the positive sequence, and no zero sequence or negative sequence signal exists, then the test result of the bus differential screen vector is qualified.

[0011] Furthermore, the step of performing online replacement operation on the faulty component of the bus differential protection device includes: withdrawing all protection pressure plates of the bus differential protection device; withdrawing the DC power switch and AC voltage switch of the protection and locking device of the bus differential protection device; disconnecting all secondary wiring of the tripping circuit of the bus differential protection device and performing insulation wrapping; replacing the protection CPU board of the bus differential protection device.

[0012] Furthermore, the test condition is that the operating light of the bus differential protection device is on, and the analog quantity and the switch quantity of the bus differential protection device are correct; the step of secondary checking the bus differential protection device includes: powering on the bus differential protection device, checking the operating light status, analog quantity and switch quantity of the bus differential protection device; judging whether the operating light of the bus differential protection device is on, and whether the analog quantity and the switch quantity are correct; if the operating light of the bus differential protection device is on, and the analog quantity and the switch quantity are correct, restoring the backed up parameters of the bus differential protection device.

[0013] Furthermore, the step of debugging the bus differential protection device includes: respectively simulating faults within and outside the double bus zone of the bus differential protection device, testing the starting and closing status of the output action contacts of the bus differential protection device, checking whether the action indicator light of the bus differential protection device is on, obtaining the action report of the bus differential protection device, and judging whether the action of the bus differential protection device is correct.

[0014] Furthermore, a primary restoration operation of the bus differential protection device includes restoring secondary connections of all tripping circuits of the bus differential protection device.

[0015] Furthermore, the secondary recovery operation of the bus differential protection device includes recovering all protection pressure plates of the bus differential protection device.

[0016] By adopting the above-mentioned method of online replacement of faulty components and transmission inspection protection of bus differential protection device, online replacement of faulty components of bus differential protection device can be realized. After the replacement of faulty components, transmission inspection of bus differential protection device can be directly carried out. The bus and feeder interval protected by the faulty bus differential protection device do not need to be powered off, nor do they need to transfer power supply loads, which greatly simplifies the work process, reduces maintenance workload, saves manpower and material resources, and greatly increases the safety and reliability of protection inspection. In addition, the method is simple and easy to implement, and is easy to promote.

[0017] The above-mentioned method for online replacement of faulty components and transmission inspection protection of the bus differential protection device, when replacing the faulty component of the bus differential panel, there is no need to shut down all the double busbars and feeder lines protected by the bus differential panel, there is no need to transfer the double bus power supply load, and the double busbars and feeder lines still remain in operation; there is no need to transfer the double busbar power supply load protected by the bus differential panel; after replacing the faulty component, use a relay protection tester to online detect the protection CPU, locking CPU and other action logics of the bus differential protection device, and test the action output of the bus differential protection device to complete the overall inspection of the bus differential protection device. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] For purposes of illustration and not limitation, the present invention will now be described in terms of preferred embodiments thereof, with particular reference to the accompanying drawings, in which:

[0019] Figure 1 It is a schematic diagram of the primary system structure of the substation;

[0020] Figure 2 It is the internal connection diagram of the busbar differential protection device;

[0021] Figure 3 This is a connection diagram of the tripping outlet terminal board of the busbar differential protection device;

[0022] Figure 4 This is a schematic diagram of the tripping outlet pressure plate of the busbar differential protection device;

[0023] Figure 5 The present invention provides a method for online replacement of faulty components and transmission inspection protection of a bus differential protection device. Figure 1 ;

[0024] Figure 6 The present invention provides a method for online replacement of faulty components and transmission inspection protection of a bus differential protection device. Figure 2 . DETAILED DESCRIPTION

[0025] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0026] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. The embodiments described are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0028] Figure 1 This is a schematic diagram of the primary system structure of the substation. The 110kV four-section busbar of the substation adopts a double-bus-coupled double-section wiring structure. Two bus differential protection devices protect the 110kV I and III sections of the busbars and the 110kV II and IV sections of the busbars respectively. If the CPU board of the 110kV I and III sections of the busbar differential protection device fails, the 110kV I and III sections of the busbars and the feeder lines need not be powered off or the power supply load of the 110kV I and III sections of the busbars needs not to be transferred to the 110kV II and IV sections of the busbars to complete the replacement of the protection CPU board and the transmission inspection of the bus differential protection device function.

[0029] Figure 2 This is a schematic diagram of the internal connection of the bus differential protection device. The bus differential protection device starts the tripping contacts of each interval branch outlet of the faulty bus through logical judgment by the protection CPU board and the locking CPU board according to the AC voltage, current signal and switch signal.

[0030] Figure 3 The bus differential protection device is connected to 14 bays, and the terminal boards are represented by 1C1D-1C14D. The tripping outlet wire numbers are: positive power supply 101 of the circuit breaker operation box, and tripping coil R133 of the circuit breaker operation box.

[0031] Figure 4 This is a schematic diagram of the tripping outlet pressure plate of the bus differential protection device. The bus differential protection device is connected to 14 intervals in total, corresponding to 14 tripping outlet pressure plates, which are represented by 1C1LP1-1C14LP1 respectively. The access interval numbers of the bus differential protection device are represented by L1-L14 respectively, and the actual name of the access interval is on the right side of the L1-L14 interval number.

[0032] The traditional method of replacing faulty components of bus differential protection devices and inspecting transmission protection requires shutting down all busbars and feeder intervals protected by the faulty bus differential protection device, or transferring the power supply load of the protected busbar to other power supply equipment before shutting down the relevant busbars and feeder lines. Both methods will cause economic losses to power grid users on the one hand, and reduce the reliability of power supply on the other hand, causing other equipment to overload at the expense of the equipment's service life. The switching operation workflow of substation duty personnel is complex, the work intensity is high, the operation time is long, and it is easy to make mistakes, requiring a lot of manpower and material resources.

[0033] In order to solve the above technical problems, the present invention proposes a method for online replacement of faulty components and transmission inspection protection of a bus differential protection device. The method replaces the faulty components of the bus differential protection device and performs whole-machine debugging of the bus differential protection without power outage to the bus and feeder lines protected by the faulty bus differential protection device. This not only ensures continuous power supply to power grid users, but also realizes the action logic verification of the bus differential protection device protection CPU board, locking CPU board, and export tripping circuit, breaking the limitation that only the export tripping circuit can be verified but the whole-machine debugging and inspection of the bus differential protection device cannot be performed.

[0034] Figure 5 and Figure 6 This is a flow chart of the method for online replacement of faulty components and transmission inspection protection of the bus differential protection device proposed by the present invention. Figure 3 , Figure 4 , Figure 5 and Figure 6 The method for online replacement of faulty components and transmission inspection protection of a bus differential protection device proposed by the present invention is described in detail.

[0035] See also Figure 5 and Figure 6 The method for online replacement of faulty components and transmission inspection protection of the bus differential protection device comprises the following steps:

[0036] S100, preliminarily check the bus differential protection device to determine whether the preliminary inspection result of the bus differential protection device meets the test conditions. If the preliminary inspection result of the bus differential protection device meets the test conditions, enter step S200.

[0037] In this embodiment, the test condition is that the bus differential protection device has no other alarm signals except the protection CPU board alarm signal, and the bus differential protection device is in an inactive state.

[0038] Among them, other alarm signals include PT short-line alarm, CT disconnection alarm and other abnormal alarm signals of the bus differential protection device itself. When the bus differential protection device has other alarms, it means that the bus differential protection device itself is abnormal, or the secondary circuit is abnormal. In this case, if the cause is not found out and the next working link is entered, it may cause the transmission inspection protection to refuse to operate or operate incorrectly.

[0039] Among them, the bus differential protection device is in the unactivated state, which means that there is no out-of-zone fault or power system disturbance on the bus of the bus differential protection device. The bus differential protection device is in the activated state, which generally means that there is an out-of-zone fault or system disturbance on the bus of the bus differential protection device. In this case, the out-of-zone fault may develop into an in-zone fault. The protection must ensure that there is no false operation in the event of an out-of-zone fault and no refusal to operate in the event of an in-zone fault. At this time, it is not appropriate to replace the faulty component and perform transmission inspection protection on the bus differential protection device. It is necessary to wait until the activation state of the bus differential protection device is eliminated before performing faulty component replacement and transmission inspection protection.

[0040] In step S100, the specific implementation method of the preliminary inspection of the busbar differential protection device is:

[0041] The alarm signal and startup status of the bus differential protection device are preliminarily checked by the on-site detection equipment. When the on-site detection equipment detects that the bus differential protection device has no other alarm signals except the alarm signal of the protection CPU board, and the bus differential protection device is in an unstarted state, step S200 is entered. When the on-site detection equipment detects that the bus differential protection device has other alarm signals except the alarm signal of the protection CPU board, and / or the bus of the bus differential protection device has an out-of-zone fault or a power system disturbance, the bus differential protection device is inspected to remove the alarm signal and / or remove the waiting-to-start state.

[0042] S200, backup bus differential protection device parameters.

[0043] In this embodiment, the bus differential protection device parameters include bus differential protection device system parameters, protection settings, bus and interval settings. Among them, the bus differential protection device system parameters include: voltage transformer parameters, current transformer primary parameters and current transformer secondary parameters. Protection settings include: bus differential starting settings, bus coupling, segment failure and dead zone protection settings, bus coupling, segment charging protection settings, etc. Bus and interval settings include: bus number settings, interval operation number settings, current phase reference settings, etc. It is necessary to use the printer supporting the bus differential protection device to print the above parameters for backup, and re-enter the backup information into the bus differential protection device after the protection CPU board is replaced.

[0044] S300, preliminarily testing the bus differential screen vector of the bus differential protection device to determine whether the preliminary test result of the bus differential screen vector is qualified. If the preliminary test result of the bus differential screen vector is qualified, proceed to step S400.

[0045] In this embodiment, the bus differential screen vector of the bus differential protection device is preliminarily tested by a field test device, and whether the bus differential screen vector is correct is determined based on the preliminary test results. If the bus differential screen vector is correct, it indicates that the bus differential screen vector test is qualified, and the process proceeds to step S400. If the bus differential screen vector is incorrect, it is necessary to find out the cause and overhaul the bus differential protection device. After the overhaul is completed, the bus differential screen vector is tested again, and the above steps are repeated until the bus differential screen vector is correct.

[0046] Exemplarily, the bus differential screen vector of the bus differential protection device includes the small differential current, large differential current, voltage amplitude and phase of the dual busbars of the bus differential protection device. If the small differential current and large differential current of the dual busbars of the bus differential protection device should be close to 0, the voltage amplitude should be balanced, the voltage phase meets the positive sequence, and there is no zero sequence or negative sequence signal, then it indicates that the bus differential screen vector is correct, that is, the sampling and logic operation functions of the locking CPU board are operating normally and will not cause the bus differential protection device to malfunction; otherwise, if the bus differential screen vector is wrong, it is necessary to find out the cause and repair the bus differential protection device.

[0047] S400: Perform online replacement operation on the faulty component of the bus differential protection device.

[0048] In this embodiment, the online replacement operation includes withdrawing all protection pressure plates of the bus differential protection device, withdrawing the DC power switch and AC voltage switch of the protection and locking device of the bus differential protection device, disconnecting all tripping circuit secondary wirings of the bus differential protection device, and replacing the protection CPU board of the bus differential protection device. Specifically, the specific implementation of step S400 is:

[0049] S401, exit all protection pressure plates of the mother differential protection device.

[0050] In this embodiment, the protection pressure plate includes a protection tripping outlet pressure plate and a differential input function hard pressure plate of the mother differential protection device. The specific implementation of step S401 is as follows:

[0051] (1) Withdrawal Figure 4 The shown diagram shows 1C1LP1-1C14LP1 protection tripping pressure plates, 14 in total.

[0052] (2) Exit the differential input function hard pressure plate of the mother differential protection device, a total of 1.

[0053] (3) Exit the bus differential protection device bus coupling and segmented charging protection function hard pressure plates, a total of 3.

[0054] S402, exit the protection of the bus differential protection device and the DC power switch and AC voltage switch of the locking device.

[0055] In this embodiment, the protection and locking device DC power switch and AC voltage switch of the mother differential protection device are exited, which can prevent the protection CPU board from being burned due to DC grounding, short circuit, electric shock or plug-in connection error when replacing the protection CPU board.

[0056] S403, disconnect all secondary wiring of the tripping circuit of the mother differential protection device and carry out insulation wrapping.

[0057] In step S403, the specific implementation process of disconnecting all secondary connections of the tripping circuit of the bus differential protection device and performing insulation wrapping is as follows: the tripping connection of the bus differential protection device on the line, secondary side of the main transformer, section, and bus-coupler interval protection panel side should be disconnected first, and then the line on the panel side of the bus differential protection device, the secondary side of the main transformer, section, and bus-coupler tripping connection should be disconnected. After the connections on both sides are removed, conspicuous markings and insulation wrapping measures should be taken at the same time.

[0058] In this embodiment, the tripping connection lines of the bus differential protection device on the line, the secondary side of the main transformer, the section, and the bus tie protection panel side are disconnected first, and then the tripping connection lines on the panel side of the bus differential protection device are disconnected. The purpose is:

[0059] (1) Prepare for the transmission of the bus differential protection device to avoid false protection operation during the transmission of the protection device, which may cause the circuit breaker of the operating equipment to trip.

[0060] (2) After disconnecting the secondary wiring of all tripping circuits of the bus differential panel, the bus differential protection device can be driven and the start-up status of the protection action output contacts can be tested at the same time.

[0061] S404, replace the protection CPU board of the mother differential protection device.

[0062] When replacing the protection CPU board of the mother differential protection device, the maintenance personnel should wear an electrostatic release ring on their wrists in advance to prevent static electricity from breaking through the protection CPU board.

[0063] S500, secondary check the bus differential protection device to determine whether the secondary check result of the bus differential protection device meets the debugging conditions. If so, proceed to step S600.

[0064] In this embodiment, the debugging condition is that the operating light of the bus differential protection device is on, and the analog quantity and switch quantity of the bus differential protection device are correct. The analog quantity includes the sampling accuracy of analog quantities such as current and voltage. In step S500, the specific implementation method of the secondary check of the bus differential protection device is:

[0065] S501, the busbar differential protection device is powered on.

[0066] After the replacement of the protection CPU board of the mother differential protection device is completed, check whether the board connection plug-in is correctly connected. After the fixing screws are tightened, add the mother differential protection screen to protect and lock the DC power switch and AC voltage switch of the device.

[0067] S502, check the operating light status, alarm signal, start signal, analog quantity and switch quantity of the bus differential protection device, and determine whether the operating light of the bus differential protection device is on, there is no alarm signal, and whether the analog quantity and switch quantity are correct; if the operating light of the bus differential protection device is on, and the analog quantity and switch quantity are correct, go to step S503. If the operating light of the bus differential protection device is on, there is an alarm signal, and / or the analog quantity and switch quantity are incorrect, repair the bus differential protection device, and repeat the above steps until the operating light of the bus differential protection device is on, and the analog quantity and switch quantity are correct.

[0068] Among them, the operating light status of the bus differential protection device is the operating light status of the protection CPU and the locking CPU of the bus differential protection device.

[0069] Among them, the method to judge whether the analog quantity and switch quantity are correct is:

[0070] Compare the sampling accuracy of analog quantities such as current and voltage of the bus differential protection device with the sampling accuracy of the line protection screen. If the two are the same, the analog quantities of the bus differential protection device are correct.

[0071] After the bus differential protection device is powered on, check whether the protection CPU and locking CPU operation lights of the bus differential protection device are lit normally, whether the bus differential protection device has alarm signals and start signals, whether the voltage, current analog quantities and input quantities of the bus differential protection device are correct, calibrate the internal clock of the bus differential protection device to ensure that it is consistent with the GPS time synchronization, and can realize automatic time synchronization.

[0072] S503, restore the backed-up bus differential protection device parameters, where the bus differential protection device parameters include system parameters, protection settings, bus and bay settings, etc. of the bus differential protection device.

[0073] Re-enter the bus differential protection device parameters according to the bus differential protection device parameters backed up by the printing device, including the system parameters, protection settings, bus and interval settings of the differential protection device.

[0074] S600, debug the bus differential protection device and perform a recovery operation on the bus differential protection device.

[0075] In this embodiment, the debugging operation of the bus differential protection device includes debugging the single function of the bus differential protection device. Exemplarily, a relay protection tester is used to simulate the double busbar faults in and out of the bus differential protection device, test the closing of the bus differential protection device outlet action contacts, and check and print whether the bus differential protection device action report is correct.

[0076] In step S600, the specific implementation method of debugging the bus differential protection device is:

[0077] (1) Disconnect the 110kV I bus voltage switch of the bus differential protection screen, open the I bus composite voltage lock, use the two spare intervals of the bus differential protection screen, force the small knife switch position of the two spare intervals of the bus differential protection screen to 110kV I bus, use the relay protection tester to pass current in the two spare intervals to simulate the 110kV I section bus zone and outside the zone fault. In case of outside zone fault, the protection device should be reliably braked, and in case of inside zone fault, it should be reliably operated. Test the start-up status of all interval protection output action contacts connected to the 110kV I bus, check whether the 110kV I bus protection action indicator is normally lit, check whether the protection device action report is correct, and print it.

[0078] (2) Disconnect the 110kV III bus voltage switch of the bus differential protection screen, open the III bus composite voltage lock, use the two spare intervals of the bus differential protection screen, force the small knife switch position of the two spare intervals of the bus differential protection screen to 110kV IIII bus, use the relay protection tester to pass current in the two spare intervals to simulate the 110kV III section bus zone and outside the zone fault. In the event of an outside fault, the protection device should be reliably braked, and in the event of an inside fault, it should be reliably operated. Test the start-up status of the protection outlet action contact of the interval connected to the 110kV III bus, check whether the 110kV III bus protection action indicator is normally lit, check whether the protection device action report is correct, and print it.

[0079] (3) Provide a 110kV I bus voltage switch on the upper bus differential protection screen, use two spare intervals of the bus differential protection screen, force the small knife switches in the two spare intervals of the bus differential protection screen to 110kV I bus, and use a relay protection tester to pass current in the two spare intervals to simulate a fault in the 110kV I section bus area. At this time, the 110kV I bus voltage is normal, the composite voltage interlock is not open, the bus differential protection device does not operate at the output, and the 110kV I bus composite voltage interlock is valid.

[0080] (4) Give the upper bus differential protection screen a 110kV III bus voltage switch, use the two spare intervals of the bus differential protection screen, force the small knife switch position of the two spare intervals of the bus differential protection screen to 110kV III bus, use the relay protection tester to pass current in the two spare intervals to simulate the fault in the 110kV III section bus area. At this time, the 110kV IIII bus voltage is normal, the composite voltage lock is not open, the bus differential protection device does not operate at the export, and the 110kV III bus composite voltage lock is effective.

[0081] In this embodiment, the primary restoration operation of the bus differential protection device includes restoring the secondary wiring of all tripping circuits of the bus differential protection device. After the single function debugging of the bus differential protection device is completed, the tripping connection of the bus differential protection device panel side is restored first, and then the tripping connection of the bus differential protection device on the line, main transformer secondary side, section, and bus tie protection panel side is restored.

[0082] S700, secondary testing the bus differential screen vector of the bus differential protection device to determine whether the secondary test result of the bus differential screen vector is qualified. If the secondary test result of the bus differential screen vector is qualified, proceed to step S800.

[0083] In this embodiment, the bus differential screen vector of the bus differential protection device is tested twice by a field test device, and whether the bus differential screen vector is correct is determined based on the secondary test result. If the bus differential screen vector is correct, it indicates that the bus differential screen vector test is qualified, and the process goes to step S800. If the bus differential screen vector is wrong, it is necessary to find out the cause and overhaul the bus differential protection device. After the overhaul is completed, the bus differential screen vector is tested again, and the above steps are repeated until the bus differential screen vector is correct.

[0084] The qualified secondary test results of the bus differential screen vector can reflect whether the sampling and logical calculation of the protection CPU board and the locking CPU board of the bus differential protection device are correct, and can also reflect whether there are problems with the secondary analog circuit and the parameters of the fixed value notification sheet. The secondary test bus differential screen vector includes the double bus small differential current, large differential current, voltage amplitude and phase of the bus differential protection device. The small differential current and large differential current should be close to 0, the voltage amplitude should be balanced, and the voltage phase should meet the positive sequence. There is no zero sequence or negative sequence signal, indicating that the sampling and logical operation functions of the protection CPU board and the locking CPU board are operating normally and will not cause the bus differential protection device to malfunction.

[0085] S800, perform secondary recovery operation on the bus differential protection device.

[0086] In this embodiment, the secondary recovery operation of the bus differential protection device includes restoring all protection plates of the bus differential protection device. In step S800, the specific implementation method of performing the secondary recovery operation on the bus differential protection device is:

[0087] According to the requirements of the fixed value notification, first put the differential input function hard pressure plate of the bus differential protection device into operation, and use a multimeter to test Figure 4 The shown 1C1LP1-1C14LP1 has a total of 14 protection tripping pressure plates. The upper and lower ends of the pressure plates have a DC voltage to ground. The voltage at the upper end of the pressure plate is -110V, and there should be no voltage at the lower end of the pressure plate. After checking that everything is correct, put the 14 protection tripping pressure plates 1C1LP1-1C14LP1 into operation.

[0088] The above-mentioned method for online replacement of faulty components and transmission inspection protection of the bus differential protection device can realize the replacement of faulty components and transmission inspection protection functions of the double busbars and feeder line intervals protected by the bus differential protection device without power outage, thereby avoiding the economic losses caused to power users by the traditional power outage inspection method. Since the present invention uses a relay protection tester to perform functional inspection on the bus differential protection device, it breaks the limitation of only checking the secondary circuit of the bus differential protection device outlet and failing to detect the action logic of the protection CPU board and the locking CPU board.

[0089] The above-mentioned busbar differential protection device online replacement of faulty components and transmission inspection protection method can also avoid the situation where the double busbar is shut down after load transfer due to transmission inspection protection, which causes serious overload of other power supply equipment and shortens the normal service life. The present invention omits the complicated workflow caused by the switching operation process of the substation duty personnel, high work intensity, long operation time, easy to make mistakes, and requires a lot of manpower and material resources, thereby improving labor productivity and shortening equipment maintenance time.

[0090] The above-mentioned method of online replacement of faulty components and transmission inspection protection of the bus differential protection device is not only aimed at the replacement of the protection CPU board and the transmission inspection of the protection device, but can also be extended to the replacement and transmission inspection of the locking CPU board or the management CPU board. It has strong scalability, is simple and easy to learn, easy to master, has a short working cycle and low labor intensity.

[0091] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions may occur depending on design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for online replacement of faulty components and transmission inspection protection of a busbar differential protection device, characterized in that: include: Preliminarily inspect the bus differential protection device to determine whether the preliminary inspection result of the bus differential protection device meets the test conditions; If the preliminary inspection result of the bus differential protection device meets the test condition, backing up the parameters of the bus differential protection device; The test conditions are that the bus differential protection device has no other alarm signals except the protection CPU board alarm signal, and there is no out-of-zone fault or power system disturbance in the bus portion of the bus differential protection device; Preliminarily test the bus differential screen vector of the bus differential protection device to determine whether the preliminary test result of the bus differential screen vector is qualified; if the preliminary test result of the bus differential screen vector is qualified, perform an online replacement operation on the faulty component of the bus differential protection device; the bus differential screen vector of the bus differential protection device includes the double bus small differential current, large differential current, voltage amplitude and phase of the bus differential protection device; If the small differential current and large differential current of the double busbars approach 0, the voltage amplitude is balanced, the voltage phase satisfies the positive sequence, and there is no zero sequence or negative sequence signal, then the test result of the bus differential screen vector is qualified; Re-checking the bus differential protection device to determine whether the re-check result of the bus differential protection device meets the debugging condition; If satisfied, the bus differential protection device is debugged, and a recovery operation is performed on the bus differential protection device; the recovery operation of the bus differential protection device includes restoring the secondary wiring of all tripping circuits of the bus differential protection device; The debugging condition is that the operating light of the bus differential protection device is on, and the analog quantity and switch quantity of the bus differential protection device are correct; The step of secondary checking the bus differential protection device comprises: The bus differential protection device is powered on, and the operating light status, analog quantity and switch quantity of the bus differential protection device are checked; whether the operating light of the bus differential protection device is on, and whether the analog quantity and switch quantity are correct; If the operating light of the bus differential protection device is on, and the analog quantity and the switch quantity are correct, restore the backed-up parameters of the bus differential protection device; Secondarily test the mother differential screen vector of the mother differential protection device to determine whether the secondary test result of the mother differential screen vector is qualified; if the secondary test result of the mother differential screen vector is qualified, perform a secondary recovery operation on the mother differential protection device; the secondary recovery operation of the mother differential protection device includes restoring all protection pressure plates of the mother differential protection device.

2. The method for online replacement of faulty components and transmission inspection protection of a busbar differential protection device according to claim 1 is characterized in that: The steps of preliminarily checking the busbar protection device include: Check the alarm signal of the busbar protection device to determine whether the busbar protection device has other alarm signals besides the alarm signal of the CPU board; Detecting whether there is an out-of-zone fault or power system disturbance on the busbar of the busbar protection device; If the busbar protection device has no other alarm signals except the alarm signal of the protection CPU board, and there is no out-of-zone fault or power system disturbance in the busbar part of the bus differential protection device, then the bus differential protection device meets the test conditions; otherwise, it does not meet the test conditions.

3. The method for online replacement of faulty components and transmission inspection protection of a busbar differential protection device according to claim 1 is characterized in that: The bus differential protection device parameters include bus differential protection device system parameters, protection settings, bus and interval settings.

4. The method for online replacement of faulty components and transmission inspection protection of a bus differential protection device according to claim 1 is characterized in that: The step of performing an online replacement operation on a faulty component of a bus differential protection device comprises: withdraw all protection pressure plates of the busbar differential protection device; A DC power switch and an AC voltage switch of the protection and locking device of the bus differential protection device are exited; Disconnect all secondary wiring of the tripping circuit of the busbar differential protection device and make insulation wrapping; Replace the protection CPU board of the mother differential protection device.

5. The method for online replacement of faulty components and transmission inspection protection of a bus differential protection device according to claim 1 is characterized in that: The step of debugging the bus differential protection device comprises: Simulate the double busbar faults in and out of the zone of the bus differential protection device respectively, test the starting and closing status of the output action contacts of the bus differential protection device, check whether the action indicator light of the bus differential protection device is on, obtain the action report of the bus differential protection device, and judge whether the action of the bus differential protection device is correct.

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