A main transformer protection auxiliary checking tool

Abstract

The application belongs to the field of main transformer protection verification, and particularly relates to a main transformer protection auxiliary verification tool. The tool comprises a plurality of parallel timing units, each of which comprises: an analog fault signal receiving and forwarding module, which is used to emit an electric signal to a tripping execution module and a timing start triggering module; a tripping contact signal receiving and forwarding module, which is used to receive and forward the electric signal of the tripping execution module to a timing end triggering module; and a timer, which is used to start and end timing by receiving the electric signals of the timing start triggering module and the timing end triggering module in sequence. The auxiliary verification tool is used to verify whether the tripping responds and to count the response time of the tripping, so as to complete the verification of the tripping logic matrix of the main transformer.

Description

Technical Field

[0001] This application belongs to the field of main transformer protection verification, and specifically relates to a main transformer protection auxiliary verification tool. Background Technology

[0002] As a core piece of equipment in the power system, the main transformer in a substation is responsible for converting high-voltage electrical energy into low-voltage electrical energy to meet the electricity needs of different users. However, due to the complex and ever-changing operating environment, the main transformer may encounter various faults and abnormal situations during operation. In such cases, the main transformer protection device can promptly detect and isolate the faults, thereby effectively ensuring the safe operation of the main transformer.

[0003] To ensure that the main transformer protection device can operate reliably when the main transformer fails, relay protection professionals need to perform regular verification of the main transformer protection device and secondary circuit. Therefore, it is especially important to be able to perform the verification work accurately and quickly.

[0004] Definitions:

[0005] "Main transformer protection" refers to the protection measures implemented for the main step-down transformer of a substation, which involves real-time monitoring and fault isolation through a device system.

[0006] "Main transformer tripping logic matrix": This is a logic judgment tool used for power system protection. It uses preset matrix operation rules to determine whether the main transformer has failed based on the real-time status parameters of the power system and the information of the protection equipment, and decides whether to trip in order to protect the safe operation of the power system.

[0007] After statistical analysis and confirmation of the actual main transformer protection verification data at the substation site, it was finally determined that the main transformer tripping logic matrix verification, a key aspect of the main transformer protection verification, takes a long time mainly because there are many test tripping output contacts. Utility Model Content

[0008] Technical problem: The technical problem to be solved by this application is to provide a verification device for simultaneously detecting the trip response time of multiple trip points.

[0009] Technical solution: A main transformer protection auxiliary verification tool, comprising several parallel timing units.

[0010] Each timing unit includes:

[0011] The simulated fault signal receiving and forwarding module is used to transmit electrical signals to the trip execution module and the timing start trigger module;

[0012] The trip contact signal receiving and forwarding module is used to receive and forward the electrical signal from the trip execution module to the timing end trigger module;

[0013] The timer is used to receive electrical signals from the timing start trigger module and the timing end trigger module in sequence to start and end the timing.

[0014] Common main transformer protection trip logic matrix outputs include:

[0015] High-voltage side circuit breaker trip output: When a fault occurs on the high-voltage side of the main transformer, or when a fault occurs on other sides of the main transformer requiring tripping of all sides, the high-voltage side circuit breaker will act as the trip output. For example, in cases such as the operation of the main transformer differential protection or the operation of the high-voltage side backup protection, the high-voltage side circuit breaker will trip.

[0016] Medium-voltage side circuit breaker trip output: When a fault occurs on the medium-voltage side of the main transformer, or when a fault occurs on other sides of the main transformer requiring tripping of all sides, the high-voltage side circuit breaker will act as the trip output. The medium-voltage side circuit breaker will trip in cases such as when the medium-voltage side backup protection operates or the main transformer differential protection operates.

[0017] Low-voltage side circuit breaker trip output: When a fault occurs on the low-voltage side of the main transformer, such as the low-voltage side overcurrent protection or time-limited instantaneous overcurrent protection operating, or the main protection of the main transformer requiring tripping of all sides, the low-voltage side circuit breaker will trip.

[0018] Activation of Failure Protection Output: When the main transformer protection issues a trip command, if the corresponding circuit breaker fails to operate, and the current flowing through the current transformer of that circuit breaker exceeds the failure initiation current value, the failure protection output will be activated. After activation, the failure protection will trip other circuit breakers related to the failed-to-operate circuit breaker.

[0019] Releasing the composite voltage blocking output: Failure protection typically employs composite voltage blocking to prevent maloperation of the protection output relay, which could lead to maloperation of the failure protection. However, in certain situations, such as a fault on the low-voltage side of the transformer causing the high-voltage side circuit breaker to fail, and in such cases, the composite voltage blocking of the failure protection may not be able to be released, it is necessary to release the voltage blocking by releasing the composite voltage output to enable the failure protection to operate reliably.

[0020] High-voltage side bus tie circuit breaker tripping output: In a double busbar connection mode, if a circuit breaker on the high-voltage side fails, the failure protection will trip the high-voltage side bus tie circuit breaker within a short time limit to isolate the faulty busbar from the normal busbar and reduce the power outage area.

[0021] Medium-voltage side bus tie circuit breaker tripping output: When the medium-voltage side circuit breaker fails, the medium-voltage side bus tie circuit breaker will trip under the failure protection action to prevent the fault from spreading to other equipment connected to the medium-voltage side bus.

[0022] Low-voltage side bus tie circuit breaker trip output: When the low-voltage side circuit breaker fails or a fault occurs on the low-voltage side bus, the low-voltage side bus tie circuit breaker may act as a trip output to disconnect the faulty bus from other parts and ensure the safe and stable operation of the system.

[0023] Therefore, it is necessary to set up 8 timing units to time and verify the tripping logic of the main transformer protection.

[0024] Furthermore, it also includes a power supply module for providing 24V DC power, comprising a positive terminal and at least 8 negative terminals, supporting multiple independent power supplies, and providing independent power support for each timing unit.

[0025] Furthermore, the simulated fault signal receiving and forwarding module is an interface module for a relay protection tester, including several interface terminals. It provides simulated fault signals to the verification device, triggering trip protection.

[0026] Furthermore, the timing unit also includes:

[0027] The relay, specifically the first relay, has a 2-on, 2-off structure and a self-holding function; normally open contacts are used to send trip signals and timing start trigger signals respectively, while normally closed contacts control related indicator lights.

[0028] The second relay is used to receive signals from the auxiliary contacts. Its normally open contact is used to connect a trip indicator light to indicate that the trip is complete, and its normally closed contact is used to trigger a signal to stop the timing.

[0029] The indicator light is electrically connected to the trip contact signal receiving and forwarding module and is used to display the trip status, supporting dual indication of open and closed positions;

[0030] The trip auxiliary contact module is used to indicate the status of the trip execution module;

[0031] Wherein: after receiving the signal from the relay protection tester interface module, the relay module triggers the indicator module, timer module, trip position signal module and switch status signal module. At the same time, the timer module records the action time and presents it through the display module.

[0032] Furthermore, in the wiring of the auxiliary verification device circuit, one set of relay modules is self-holding, and the ignition lamp is connected to a normally open contact, while the closing lamp is connected to a normally closed contact, with a set of spare contacts reserved.

[0033] The power module also includes overvoltage and overcurrent protection circuits to ensure safe operation of the device under abnormal voltage or current conditions.

[0034] The beneficial effects of this application are as follows:

[0035] Multi-point synchronous detection: By setting up 8 parallel timing units, it is possible to simultaneously detect the response time of multiple trip points (such as the high, medium and low voltage circuit breakers of the main transformer, start failure, release of composite voltage blocking, high, medium and low voltage bus tie circuit breakers, etc.), to meet the diverse needs of main transformer protection and improve the efficiency and comprehensiveness of verification.

[0036] Precise time measurement: The timer sequentially receives electrical signals from the timing start trigger module and the timing end trigger module, realizing the precise recording and presentation of the trip response time, effectively verifying the action time limit of the protection device, and enhancing reliability.

[0037] Independent power supply support: The power module provides 24V DC power and includes a positive terminal and at least 8 negative terminals, supporting multiple independent power supplies to ensure stable operation of each timing unit, reduce mutual interference, and improve system stability.

[0038] Flexible signal triggering: The simulated fault signal receiving and forwarding module adopts the relay protection tester interface module, equipped with multiple interface terminals, which can flexibly provide simulated fault signals, accurately trigger the trip protection logic, and adapt to various verification scenarios.

[0039] Diverse control and indication: The relay module adopts a 2-open, 2-closed structure and has a self-holding function. The normally open contact is used to send trip signals and timing start signals, and the normally closed contact is combined with the indicator light to display the status. The second relay controls the digit indicator light through the normally open contact and triggers the timing stop through the normally closed contact, realizing multi-functional control and status monitoring.

[0040] Intuitive status display: The indicator module supports dual indication of open and closed positions, and is electrically connected to the trip contact signal receiving and forwarding module to clearly reflect the trip status, making it easy for operators to monitor the equipment operation in real time.

[0041] Optimized auxiliary verification: The trip auxiliary contact module and the reserved spare contact design enhance the expandability of the verification device, support independent connection of self-holding, open position lamp and closed position lamp, meet complex verification requirements and facilitate maintenance and upgrades.

[0042] Highly integrated: The device integrates relay modules, timer modules, indicator light modules, trip position signal modules, and switch status signal modules. By uniformly receiving signals from the relay protection tester, it achieves integrated management of action time recording and status display, improving the automation and intelligence level of the verification process. Attached Figure Description

[0043] Figure 1 This is a schematic block diagram of the timing unit in this application;

[0044] Figure 2 This is the electrical wiring diagram of the timing unit in this application;

[0045] Figure 3 This is the circuit schematic diagram of this application;

[0046] Figure 4 This is a wiring diagram for this application. Detailed Implementation

[0047] Reference Figure 1-2 , Figure 2 In the diagram, V1+ is a simulated fault signal, V2+ is a single-channel power supply, TJ is the trip execution terminal, DL is the auxiliary contact signal, JS1 is a timing module, and KZ1-4 and KZ1-6 are two relays respectively.

[0048] Reference Figure 2 The overall principle of the timing unit in this application is that the timing module is connected to the normally open contact of relay KZ1-4 and the normally closed contact of relay KZ1-6 on the left and right sides respectively. The control coil of KZ1-4 is connected to the analog fault output terminal V1+, and the control coil of KZ1-6 is connected to the auxiliary contact signal transmitting terminal on the trip TJ side.

[0049] When the simulated fault signal is issued, the normally open contact of KZ1-4 closes, and the timer JS1 forms a complete closed circuit and starts timing. After the trip is completed, the auxiliary contact signal DL sends an electrical signal to KZ1-6, the normally closed contact of KZ1-6 opens, the timer JS1 circuit is disconnected, and the timing ends.

[0050] For connecting the separate and combined lamps, those skilled in the art can use multi-contact relays to connect in parallel with the corresponding relays.

[0051] Those skilled in the art can refer to existing technologies to connect the required push-button switches for functions such as main switch and / or individual control switch buttons, as well as timer reset.

[0052] Reference Figure 3 The entirety of this application is based on Figure 2 Based on the fundamental principle, a total of 8 timing modules, JS1-JS8, are connected in parallel, corresponding to the trip outputs of the main transformer high-voltage side circuit breaker, medium-voltage side circuit breaker, low-voltage side circuit breaker, start-up failure protection, release of composite voltage blocking, high-voltage side bus tie circuit breaker, medium-voltage side bus tie circuit breaker, and low-voltage side bus tie circuit breaker.

[0053] KZ1-4, KZ1-6~KZ8-4, and KZ8-6 are relay modules used to control JS1-JS8, respectively.

[0054] The wiring for this device during use is as follows: Figure 4 As shown, the wiring and usage are as follows:

[0055] 1. Connect the main transformer protection auxiliary verification tool 1D:1 to a 24V DC power supply.

[0056] 2. Connect the main transformer protection auxiliary verification tools 2D:7 and 2D:8 to the relay protection tester.

[0057] 3. Connect the main transformer protection auxiliary verification tools 1D:15 and 1D:34 to the trip position of the high-voltage side switch of the main transformer.

[0058] 4. Connect the main transformer protection auxiliary verification tools 1D:16 and 1D:34 to the trip position of the main transformer's intermediate voltage side switch.

[0059] 5. Connect the main transformer protection auxiliary verification tools 1D:17 and 1D:35 to the trip position of the low-voltage side switch of the main transformer.

[0060] 6. Connect the main transformer protection auxiliary verification tools 1D:18 and 1D:35 to the main transformer's high-voltage side bus tie and sectionalizing switch trip positions.

[0061] 7. Connect the main transformer protection auxiliary verification tools 1D:19 and 1D:36 to the trip positions of the main transformer's intermediate voltage side bus tie and sectionalizing switch.

[0062] 8. Connect the main transformer protection auxiliary verification tools 1D:20 and 1D:36 to the trip positions of the low-voltage side bus tie and sectionalizing switch of the main transformer.

[0063] Main transformer protection trip logic matrix verification process:

[0064] 1. Manually close the auxiliary verification tool for the main transformer protection, including the high-voltage side, medium-voltage side, low-voltage side, high-voltage side bus tie, medium-voltage side bus tie, and low-voltage side bus tie switches.

[0065] 2. Input data into the relay protection tester and start.

[0066] 3. When a fault condition is triggered, all timers in the auxiliary verification tool for the main transformer protection start timing simultaneously.

[0067] 4. The test involves the tripping of the circuit breaker, the green light turning on, and the corresponding timer stopping.

[0068] 5. After the test, all other switches should be in the closed position, and the timing should be paused.

[0069] 6. Determine whether the tripping switches and their sequence are correct based on the setpoint matrix, the main transformer protection auxiliary verification tool timer, and the switch open / close position.

Claims

1. A main transformer protection auxiliary verification tool, characterized in that, It includes several parallel timing units. The timing unit includes: The simulated fault signal receiving and forwarding module is used to transmit electrical signals to the trip execution module and the timing start trigger module; The trip contact signal receiving and forwarding module is used to receive and forward the electrical signal from the trip execution module to the timing end trigger module; The timer is used to receive electrical signals from the timing start trigger module and the timing end trigger module in sequence to start and end the timing.

2. The auxiliary verification tool for main transformer protection as described in claim 1, characterized in that, It also includes a power module for providing 24V DC power, which includes a positive terminal and at least 8 negative terminals, supporting multiple independent power supplies.

3. The auxiliary verification tool for main transformer protection as described in claim 2, characterized in that, The simulated fault signal receiving and forwarding module is an interface module of the relay protection tester, which includes several interface terminals.

4. The auxiliary verification tool for main transformer protection as described in claim 3, characterized in that, The timing unit also includes: Relay; The indicator light is electrically connected to the trip contact signal receiving and forwarding module and is used to display the trip status, supporting dual indication of open and closed positions; The trip auxiliary contact module is used to indicate the status of the trip execution module. Wherein: after receiving the signal from the relay protection tester interface module, the relay triggers the indicator light, timer, trip position signal module and switch status signal module, and the timer records the action time and presents it through the display module.

5. The auxiliary verification tool for main transformer protection as described in any one of claims 2-4, characterized in that, The power module also includes overvoltage and overcurrent protection circuits to ensure safe operation of the device under abnormal voltage or current conditions.

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