An online self-checking method and system of a power grid safety and stability control system

Abstract

The application discloses an online self-checking method and system of a power grid safety and stability control system, which checks whether the state of all stability control devices is normal by a dispatching master station, executes online self-checking if normal, sends test data of a control strategy to all IOs and strategy units in a standby state in a first stability control system, checks whether the stability control strategy can be correctly executed, and uploads the test result to the dispatching master station, then performs online self-checking on the rest of the IOs and strategy units in the first stability control system through master-slave switching, and finally performs online self-checking on a second stability control system by using the above method; the application only performs online self-checking on the IOs and strategy units in the standby state, can guarantee double-set operation of the stability control system during the self-checking process, does not need to take the stability control device out of operation, and does not affect the correct action of the stability control device if a power grid fault occurs.

Description

Technical Field

[0001] This invention belongs to the field of power system and its automation technology, specifically relating to an online self-testing method and system for a power grid safety and stability control system. Background Technology

[0002] Power grid safety and stability control devices (hereinafter referred to as stability control devices) are control equipment installed in power plants or substations to ensure the stability of the power system when encountering large disturbances. They can realize functions such as generator tripping, load shedding, rapid output reduction, and emergency DC power boosting or reduction. They are important facilities for maintaining the safe and stable operation of the power system.

[0003] The power grid safety and stability control system (hereinafter referred to as the stability control system) is a system composed of safety and stability control devices of two or more power plants connected by communication equipment to achieve stable control of the power system in a region or a larger area.

[0004] Power stabilization and control devices play a crucial role in maintaining the safe and stable operation of the power grid. Their operational reliability is of great significance to the safe and stable operation of the power grid. Failure to operate or malfunction of these devices often leads to large-scale power outages, threatening the safe operation of the entire power system with very serious consequences. Therefore, it is essential to conduct scientific and reasonable maintenance of power stabilization and control devices.

[0005] Traditional maintenance methods for stability control systems primarily involve inspecting the input and output circuits of individual stability control devices. This includes testing electrical quantities such as current and voltage, digital inputs such as protection trip signals and switch position signals, and the device's output circuits. This method requires taking the stability control device out of operation, which is time-consuming and labor-intensive, and cannot verify whether the strategies of the operating stability control system are being executed correctly. Summary of the Invention

[0006] Purpose of the invention: The purpose of this invention is to provide a method for online verification of the correct execution of a power grid safety and stability control strategy; the second purpose of this invention is to provide a system for online verification of the correct execution of a power grid safety and stability control strategy.

[0007] Technical solution: The online self-testing method for the power grid safety and stability control system of the present invention includes the following steps:

[0008] (1) The dispatch master station obtains the operating status of all stability control devices in the stability control system. If the operating status is normal, the online self-test conditions are met and step (2) is executed; otherwise, the online self-test conditions are not met.

[0009] (2) Set all first IO and strategy units in the first stability control system to the main operation state and set all second IO and strategy units in the first stability control system to the standby operation state, then all second IO and strategy units are units to be tested;

[0010] Both the first IO and strategy unit and the second IO and strategy unit include a host chassis and a slave chassis;

[0011] (3) The scheduling master station sends test data of the control strategy to the unit under test. The unit under test starts executing the control strategy at the start time T of the test and sends the test results to the scheduling master station in real time.

[0012] (4) Repeat steps (1) to (3) to complete the testing of all control strategies on the unit under test;

[0013] (5) Switch the first IO and strategy unit to standby mode and switch the second IO and strategy unit to main mode, then the first IO and strategy unit is the unit to be tested; execute steps (3) and (4); complete the online self-test of the first stability control system;

[0014] (6) Repeat steps (1) to (5) to complete the online self-test of the second stability control system;

[0015] The first and second stability control systems are each composed of several stability control devices, and each stability control device includes a first I / O and strategy unit and a second I / O and strategy unit.

[0016] Further, in step (3), the scheduling master station sends test data of the control strategy to the unit under test, and the unit under test starts executing the control strategy at the test start time T, including:

[0017] After receiving the test data, the unit under test prepares for the test and sends a notification to the scheduling master station indicating that it is ready for the test.

[0018] Once the master station determines that all units under test have completed test preparation, it sends a test start flag and test start time T to the units under test.

[0019] The unit under test begins executing the control strategy at test start time T.

[0020] Furthermore, the execution of the control strategy by the unit under test at the start time T of the test in step (3) includes:

[0021] The unit under test executes the control strategy at the start time T of the test, including data simulation, fault diagnosis, logic calculation and control decision; generates self-test data and completes communication between the units under test through the communication unit and SDH transmission system;

[0022] The frame header of the self-test data is different from the frame header of the real data. The self-test data includes command data and ordinary data.

[0023] Furthermore, the control strategy implemented by the unit under test in step (3) at the start time T of the test includes: the unit under test that needs a local output does not actually output after receiving the self-test output command, but only sends a message indicating that the self-test output command has been received.

[0024] Further, the method for switching the first IO and the strategy unit to standby mode and switching the second IO and the strategy unit to active mode in step (4) is as follows:

[0025] If the first IO and strategy unit malfunctions due to manual external measures, the second IO and strategy unit automatically switches to the primary operating state. Then, the first IO and strategy unit is restored to normal, and the first IO and strategy unit is in the standby operating state.

[0026] Furthermore, during the online self-test, if an anomaly occurs between the first IO and the test unit or the second IO and the test unit in the main operating state, the unit under test switches to the main operating state and suspends the online self-test.

[0027] The scheduling master station determines whether all units under test are in standby mode. If all are in standby mode, the online self-test continues; otherwise, the online self-test is terminated and the process returns to step (1).

[0028] Furthermore, the test data in step (3) includes: component operating status data, output information data of the unit, water pump and load, and fault data.

[0029] The online self-testing system of the power grid security and stability control system of the present invention includes: a first stability control system, a second stability control system, and a dispatch master station;

[0030] The first and second stability control systems are each composed of several stability control devices, and each stability control device includes a first I / O and strategy unit and a second I / O and strategy unit.

[0031] The first I / O and the policy unit, and the second I / O and the policy unit, serve as backups for each other.

[0032] The scheduling master station is connected to all first IO and strategy units and second IO and strategy units, and is used to send test data of control strategies to all first IO and strategy units or second IO and strategy units in standby state in the first stability control system. The first IO and strategy units or second IO and strategy units in standby state start executing the control strategy at the start time T of the test and send the test results to the scheduling master station in real time to complete the online self-test of the first stability control system. Then, the scheduling master station sends test data of control strategies to all first IO and strategy units or second IO and strategy units in standby state in the second stability control system. The first IO and strategy units or second IO and strategy units in standby state start executing the control strategy at the start time T of the test and send the test results to the scheduling master station in real time to complete the online self-test of the second stability control system.

[0033] The electronic device of the present invention includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the computer program is loaded onto the processor, it implements the online self-testing method of the power grid safety and stability control system.

[0034] The computer-readable storage medium of the present invention stores a computer program, which, when executed by a processor, implements the online self-testing method of the power grid safety and stability control system.

[0035] Beneficial effects: Compared with the prior art, the advantages of this invention are: it verifies the correct execution of the stability control strategy from a system perspective, improving the reliability of the stability control system; when the A-set stability control system performs online self-test, the B-set stability control system still operates normally; similarly, when the B-set stability control system performs online self-test, the A-set stability control system still operates normally; this invention only performs online self-test on the IO and strategy units in standby mode, and can still ensure the dual operation of the stability control system during the self-test process without needing to take the stability control device out of operation; if a power grid fault occurs during the online self-test process, it will not affect the correct operation output of the stability control device. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the stability control device of the present invention.

[0037] Figure 2 This is a diagram of the online self-testing system architecture for power grid safety and stability control according to the present invention.

[0038] Figure 3 This is a flowchart of the online self-testing method for power grid safety and stability control according to the present invention. Detailed Implementation

[0039] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0040] The stability control device consists of a main control unit, slave control units (IO units), and a communication unit. Dedicated fiber optic cables connect the main control unit to the slave control units and the communication unit. The main control unit performs the following functions: identifying the power grid operating mode, processing control strategies, and communicating and exchanging information with main control units at other power plants; it also communicates and exchanges information with slave control units and issues control commands. The slave control units perform the following functions: collecting and judging information and sending the results to the main control unit; and executing control commands issued by the main control unit. The communication unit provides communication connectivity with multiple remote power plant stability control devices and is typically installed in the communication room at the power plant.

[0041] This invention combines the main chassis and slave chassis into an I / O and strategy unit, which has functions such as information acquisition, fault diagnosis, and decision execution. Its hardware and software are complex, and it is the core of the stability control device. The communication unit's hardware and software are relatively simple; problems encountered in the engineering field are often ultimately traced back to the I / O and strategy unit.

[0042] To improve the reliability of the stability control device, the present invention provides a stability control device architecture with redundant hot standby function, such as... Figure 1 As shown in the diagram, this architecture contains two identical I / O and strategy units, denoted as I / O and strategy unit 1 and I / O and strategy unit 2, which serve as backups for each other. If I / O and strategy unit 1 is the primary operating unit, then I / O and strategy unit 2 is the backup operating unit; conversely, if I / O and strategy unit 2 is the primary operating unit, then I / O and strategy unit 1 is the backup operating unit.

[0043] The communication unit is connected to IO and strategy unit 1 and IO and strategy unit 2 respectively through two pairs of optical fibers. It receives data from IO and strategy unit 1 and IO and strategy unit 2 at the same time. When the main IO and strategy unit fails, it achieves automatic zero-latency switching and sends the main and backup operation status to the corresponding IO and strategy unit.

[0044] The communication unit implements master / slave switching as follows: When both IO and strategy units are operating normally, IO and strategy unit 1 is the master unit and IO and strategy unit 2 is the standby unit. Data sent by IO and strategy unit 1 is used as the actual data by the communication unit to transmit commands and data between stations in the stability control system. At this time, data sent by IO and strategy unit 2 is used as self-test data. When IO and strategy unit 1 malfunctions, it automatically switches to IO and strategy unit 2 as the master unit and IO and strategy unit 1 as the standby unit. Data sent by IO and strategy unit 2 is used as the actual data by the communication unit to transmit commands and data between stations in the stability control system. At this time, data sent by IO and strategy unit 1 is used as self-test data. When IO and strategy unit 1 recovers, pressing the reset button for IO and strategy unit 1 switches to master unit and IO and strategy unit 2 switches to standby unit.

[0045] like Figure 2 As shown, the online self-testing system of the power grid security and stability control system of the present invention includes a first stability control system, a second stability control system, and a dispatch master station;

[0046] Both the first and second stability control systems are composed of several stability control devices, and each stability control device includes a first I / O and strategy unit and a second I / O and strategy unit.

[0047] The first I / O and the policy unit, and the second I / O and the policy unit, serve as backups for each other.

[0048] The scheduling master station is connected to all first IO and strategy units and second IO and strategy units, and is used to send test data of control strategies to all first IO and strategy units or second IO and strategy units in standby state in the first stability control system. The first IO and strategy units or second IO and strategy units in standby state start executing the control strategy at the start time T of the test and send the test results to the scheduling master station in real time to complete the online self-test of the first stability control system. Then, the scheduling master station sends test data of control strategies to all first IO and strategy units or second IO and strategy units in standby state in the second stability control system. The first IO and strategy units or second IO and strategy units in standby state start executing the control strategy at the start time T of the test and send the test results to the scheduling master station in real time to complete the online self-test of the second stability control system.

[0049] Through the scheduling data network, the two I / O and strategy units of the stability control device are simultaneously connected to the scheduling master station, and upload the operating status to the scheduling master station and receive test data and instructions sent by the scheduling master station.

[0050] Through the SDH transmission system between substations, the communication unit realizes communication between stability control devices. The communication content includes two parts: real data and self-test data.

[0051] The data transmission content between real data and traditional stability control systems is consistent, with a length of 24 bytes, including the following three aspects: 1) Real-time sampling data of power grid components, such as DC operating status, operating power, upgradable capacity, downgradable capacity, etc.; operating status, power, branch / switch current, bus voltage, frequency, etc. of AC components; output information of units, pumps, loads, etc.; 2) Control strategy related information, such as calculated control quantities, power loss quantities, controllable quantities sent from lower-level stations, and component fault information, etc.; 3) Command data, such as commands for tripping generators, tripping pumps, tripping loads, and modulating DC.

[0052] The self-test data is used for the online self-test of the stability control system. It is 24 bytes long and its frame header is significantly different from that of the actual data. When no self-test occurs, the self-test data is a heartbeat message; when a self-test occurs, it transmits the commands and data required for the online self-test.

[0053] The communication unit processes the data from the main operation IO and strategy unit and the backup operation IO and strategy unit using the following methods: 1) The communication unit treats the data sent by the main operation IO and strategy unit as normal data and sends it to the remote stability control device through the SDH transmission system; 2) The communication unit treats the data sent by the backup operation IO and strategy unit as self-test data and sends it to the remote stability control device through the SDH transmission system; 3) The communication unit sends the normal data received from the SDH transmission system to the main operation IO and strategy unit; 4) The communication unit sends the self-test data received from the SDH transmission system to the backup operation IO and strategy unit.

[0054] like Figure 3 As shown, the online self-testing method for the power grid safety and stability control system of the present invention includes the following steps:

[0055] Step 1: The dispatch master station obtains the operating status of all stability control devices in the stability control system in real time. If all A and B set stability control systems are in normal condition, all stability control devices are in normal time synchronization, and the IO and strategy units in standby state are also normal, then the conditions for online self-testing are met.

[0056] The A-set stability control system consists of all A-set stability control devices, and the B-set stability control system consists of all B-set stability control devices.

[0057] Step 2: In the A-set stability control system, where IO and strategy unit 2 is the main operating unit and IO and strategy unit 1 is the backup operating unit, by manually applying external measures, after pressing the reset button of IO and strategy unit 1, the main and backup operation switching of the stability control unit is completed, so that all IO and strategy units 1 in the A-set stability control system are in the main operating state, and the corresponding IO and strategy units 2 are in the backup operating state. At this time, all IO and strategy units 2 in the A-set stability control system become the units to be tested.

[0058] Step 3: Based on the information required by control strategy N, the scheduling master station sends test data to all units under test through the scheduling data network.

[0059] The information required for control strategy N mainly includes: component operating status, power, current, voltage, frequency, etc.; output information of units, pumps, loads, etc.; cross-sectional power flow; fault data such as component faults, power loss, and overload measures.

[0060] Step 4: The unit under test receives the test data sent by the scheduling master station, completes the test preparation, and then sends a notification to the scheduling master station indicating that the test preparation is complete.

[0061] Furthermore, if the main operating device malfunctions, it will cause the unit under test to switch from standby mode to main operating mode, and the unit under test will promptly report this information to the dispatch master station.

[0062] Step 4: During the self-test, if an anomaly occurs between the I / O unit in the primary operating state and the test unit, the unit under test will be automatically switched to the primary operating unit, and the self-test must be stopped immediately. The scheduling master station determines whether all units under test are still in standby state. If not, the online self-test is terminated, and the operating status of all stability control devices is reacquired; otherwise, the next step is executed.

[0063] Step 5: The scheduling master station determines whether all units under test are ready for testing. If not, it continues to wait; otherwise, it sends a test start flag and the test start time T to the units under test.

[0064] Furthermore, considering the testing requirements for channel data transmission delay and cascading failures, the start time of the test for the stability control device may be inconsistent. Therefore, according to the requirements of strategy N, the T value of each unit under test must be tuned separately.

[0065] Step Six: The unit under test receives the test start identifier and the test start time T from the scheduling master station. For a specific stability control device under test, when time T arrives, the predetermined control strategy N begins to execute. The unit under test begins to perform functions such as data simulation, fault diagnosis, logic calculation, and control decision-making, generating self-test data with a frame header different from the real data, including command or ordinary data, and completes data transmission through the communication unit and SDH transmission system.

[0066] Furthermore, for units under test that require local output, after receiving the self-test output command, the device's human-machine interface will display an action message indicating that the specific output command has been received, but it will not actually output the command, ensuring that the self-test will not cause the device to malfunction.

[0067] Step 7: The unit under test actively and in real time sends the action results to the scheduling master station.

[0068] Step 8: Based on the combined action results from all the units under test, the scheduling master station determines whether control strategy N is being executed correctly in the stability control system.

[0069] Step 9: Repeat steps 1 to 8 to complete the online self-test of all control strategies in all IOs and test unit 2 of the A-set stability control system.

[0070] Step 10: Through manual external measures, cause an anomaly in the IO and strategy unit 1 of all stability control devices in Set A stability control system. At this time, the communication unit automatically switches IO and strategy unit 2 to primary operation, completing the primary / backup switch for the stability control device. Then, IO and strategy unit 1 are restored to normal. At this time, IO and strategy unit 1 are still in standby operation, while IO and strategy unit 2 are in primary operation. Now, all IO and strategy unit 1 in Set A stability control system become the units under test. Repeat steps one through nine to complete the online self-test of all control strategies in all IO and test units 1 of Set A stability control system, thereby completing the online self-test of all control strategies in Set A stability control system.

[0071] Step 11: Repeat steps 1 to 10 to complete the online self-test of all control strategies in the B-set stability control system.

[0072] The electronic device of the present invention includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the computer program is loaded onto the processor, it implements the online self-testing method of the power grid safety and stability control system.

[0073] The computer-readable storage medium of the present invention stores a computer program, which, when executed by a processor, implements the online self-testing method of the power grid safety and stability control system.

[0074] The computer-readable storage medium may include RAM, ROM, EEPROM, CD-ROM or other optical disc storage devices, magnetic disk storage devices or other magnetic storage devices, flash memory, or any other media that can be used to store desired program code in the form of instructions or data structures and is accessible by a computer.

[0075] The processor is used to execute a computer program stored in memory to implement the various steps in the methods described in the above embodiments.

Claims

1. An online self-testing method for a power grid safety and stability control system, characterized in that, Includes the following steps: (1) The dispatch master station obtains the operating status of all stability control devices in the stability control system. If the operating status is normal, the online self-test conditions are met and step (2) is executed; otherwise, the online self-test conditions are not met. (2) Set all first IO and strategy units in the first stability control system to the main operation state and set all second IO and strategy units in the first stability control system to the standby operation state, then all second IO and strategy units are units to be tested; Both the first IO and strategy unit and the second IO and strategy unit include a host chassis and a slave chassis; (3) The scheduling master station sends test data of the control strategy to the unit under test. The unit under test starts executing the control strategy at the start time T of the test and sends the test results to the scheduling master station in real time. (4) Repeat steps (1) to (3) to complete the testing of all control strategies on the unit under test; (5) Switch the first IO and strategy unit to standby mode and switch the second IO and strategy unit to master mode, then the first IO and strategy unit is the unit to be tested; execute steps (3) and (4); complete the online self-test of the first stability control system; (6) Repeat steps (1) to (5) to complete the online self-test of the second stability control system; The first and second stability control systems are each composed of several stability control devices, and each stability control device includes a first I / O and strategy unit and a second I / O and strategy unit. Step (3) involves the scheduling master station sending test data of the control strategy to the unit under test, and the unit under test starting to execute the control strategy at the test start time T. This includes: the unit under test preparing for the test after receiving the test data and sending a notification to the scheduling master station indicating that it is ready for the test; the scheduling master station determining that all units under test have completed the test preparation and then sending a notification indicating the start of the test and the test start time T to the unit under test; and the unit under test starting to execute the control strategy at the test start time T. During the online self-test, if an anomaly occurs between the first IO and the test unit or the second IO and the test unit in the main operation state, the unit under test switches to the main operation state and the online self-test is suspended; the scheduling master station determines whether all units under test are in the standby operation state. If they are all in the standby operation state, the online self-test continues; otherwise, the online self-test is terminated and the process returns to step (1).

2. The online self-testing method for the power grid safety and stability control system according to claim 1, characterized in that, Step (3) involves the unit under test executing the control strategy at the start time T of the test, including: The unit under test executes the control strategy at the start time T of the test, including data simulation, fault diagnosis, logic calculation and control decision; generates self-test data and completes communication between the units under test through the communication unit and SDH transmission system; The frame header of the self-test data is different from the frame header of the real data. The self-test data includes command data and ordinary data.

3. The online self-testing method for the power grid safety and stability control system according to claim 1, characterized in that, Step (3) The control strategy executed by the unit under test at the start time T of the test includes: the unit under test that needs a local output sends a message indicating that it has received the self-test output command after receiving the self-test output command.

4. The online self-testing method for the power grid safety and stability control system according to claim 1, characterized in that, The method for switching the first IO and strategy unit to standby mode and the second IO and strategy unit to active mode in step (4) is as follows: If the first IO and strategy unit malfunctions due to manual external measures, the second IO and strategy unit automatically switches to the primary operating state. Then, the first IO and strategy unit is restored to normal, and the first IO and strategy unit is in the standby operating state.

5. The online self-testing method for the power grid safety and stability control system according to claim 1, characterized in that, The test data in step (3) includes: component operating status data, output information data of unit, water pump and load, and fault data.

6. An online self-testing system for a power grid safety and stability control system, characterized in that, Online self-testing is performed using the method described in any one of claims 1-5, comprising: a first stability control system, a second stability control system, and a scheduling master station; The first and second stability control systems are each composed of several stability control devices, and each stability control device includes a first I / O and strategy unit and a second I / O and strategy unit. The first I / O and the policy unit, and the second I / O and the policy unit, serve as backups for each other. The scheduling master station is connected to all first IO and strategy units and second IO and strategy units, and is used to send test data of control strategies to all first IO and strategy units or second IO and strategy units in standby state in the first stability control system. The first IO and strategy units or second IO and strategy units in standby state start executing the control strategy at the start time T of the test and send the test results to the scheduling master station in real time to complete the online self-test of the first stability control system. Then, the scheduling master station sends test data of control strategies to all first IO and strategy units or second IO and strategy units in standby state in the second stability control system. The first IO and strategy units or second IO and strategy units in standby state start executing the control strategy at the start time T of the test and send the test results to the scheduling master station in real time to complete the online self-test of the second stability control system.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the computer program is loaded into the processor, it implements the online self-testing method of the power grid security and stability control system according to any one of claims 1-5.

8. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the online self-testing method of the power grid safety and stability control system according to any one of claims 1-5.

Images