AC fault ride-through control method, apparatus, electronic equipment, and storage medium at the receiving end

Abstract

The present invention relates to a method, apparatus, electronic equipment, and storage medium for controlling AC fault ridethrough at the receiving end, relating to the technology of power transmission and distribution, and aims to solve technical problems such as imbalance in system power and insufficient coordination capability in conventional AC fault ridethrough processes at the receiving end. The method includes the steps of: determining a receiving end converter station where an AC fault has occurred as a faulty receiving end converter station; having the faulty receiving end converter station generate an AC voltage fault signal and simultaneously perform a power surplus evaluation to obtain a surplus power value; then transmitting the AC voltage fault signal and the surplus power value to an AC energy consumption device; if the faulty receiving end converter station is a receiving end constant voltage station, turning on the AC energy consumption device based on the AC voltage fault signal and the surplus power value to absorb the surplus power of the island grid; and if the faulty receiving end converter station is a receiving end constant power station, having the faulty receiving end converter station adjust its power reference value based on the surplus power value and turning on the AC energy consumption device to absorb the surplus power of the island grid.

Claims

1. A method for controlling AC fault ride-through at the receiving end, It is applied to the receiving end converter station of the multi-terminal power transmission system of the new energy island grid. The multi-terminal power transmission system further includes an AC energy consumption device and at least one transmission end converter connected to the AC energy consumption device, each of the transmission end converters being connected to at least two receiving end converters, and the method is as follows: When an AC fault is detected, the process involves generating an AC voltage fault signal and simultaneously performing a power surplus evaluation to obtain a surplus power value. The steps include transmitting the AC voltage fault signal and the surplus power value to the AC energy consumption device so that the AC energy consumption device is turned on based on the AC voltage fault signal and the surplus power value to absorb the island grid voltage surplus power, Currently, when using a constant power control method, the process further includes adjusting the power reference value based on the surplus power value, A method for controlling AC fault ride-through at the receiving end, characterized by including the following:

2. The step of performing a power surplus assessment and obtaining a surplus power value includes the step of calculating the surplus power value using the following formula: [Math 1] Here, f is the surplus power value, V ｍ＿ａｆ This is the effective value of the AC voltage after the fault occurs, V ｍ＿ｐｒｅ This is the effective value of the AC voltage before the fault occurred, P ｐｒｅ This is the active power before the failure occurred. The AC fault ride-through control method for the receiving end according to feature 1.

3. When it is detected that the AC voltage has recovered to a preset AC voltage threshold, a fault recovery signal is generated and transmitted to the AC energy consumption device so that the AC energy consumption device sequentially controls the interruption of the AC energy consumption that has already been switched on according to the interruption speed. If it is detected that the AC energy consumption device sequentially controls the interruption of already engaged AC energy consumption according to the interruption speed, and a constant power control method is currently employed, the power reference value is raised to the power level before the fault occurred according to the raising speed, The receiving end AC fault ride-through control method according to claim 1, further comprising the following:

4. If it is detected that the AC energy consumption device sequentially controls the interruption of already engaged AC energy consumption according to the interruption speed, and a constant power control method is currently employed, the step of raising the power reference value to the power before the failure occurred according to the raising speed is: If it is detected that the AC energy consumption device sequentially controls the interruption of already engaged AC energy consumption according to the interruption speed, and if a constant power control method is currently employed, then after a preset communication delay, a power increase operation is performed to synchronize with the energy consumption interruption operation by the AC energy consumption device. The receiving end AC fault ride-through control method according to claim 3, characterized by including the following:

5. A method for controlling AC fault ride-through at the receiving end, Applicable to AC energy consumption devices in the multi-terminal power transmission system of the new energy island grid, The multi-terminal power transmission system further includes at least one transmission end converter connected to the AC energy consumption device, each of the transmission end converters being connected to at least two receiving end converters, and the method is The steps include receiving an AC voltage fault signal and surplus power value transmitted by a receiving end converter station where an AC fault has occurred, A step of controlling the input to absorb surplus power from the island grid based on the AC voltage fault signal and the surplus power value, A method for controlling AC fault ride-through at the receiving end, characterized by including the following:

6. The aforementioned AC energy consumption device includes multiple groups of AC energy consumption submodules, each of which corresponds to one AC energy consumption capacity. The step of controlling the input to absorb the surplus power of the island grid based on the AC voltage fault signal and the surplus power value is: Based on the AC voltage fault signal, the number of groups of AC energy consumption submodules to be switched on is calculated using the AC energy consumption capacity and the surplus power value, and when switching on the corresponding number of AC energy consumption submodules to absorb the surplus power of the island grid, the number of groups to be switched on is rounded up. The steps include obtaining the actual total energy consumption during the surplus power absorption process, and if the actual total energy consumption is greater than the surplus power, selecting one group of AC energy consumption submodules from the multiple groups of AC energy consumption submodules as a flexible on / off energy consumption submodule, wherein the flexible on / off energy consumption submodule is used to control the difference between the actual total energy consumption and the actual fault surplus power to be maintained within ±10%. The receiving end AC fault ride-through control method according to claim 5, characterized by including the following:

7. The step of controlling the difference between the actual total energy consumption and the actual fault surplus power to be kept within ±10% is: In the process of absorbing surplus power, if the actual total energy consumption is greater than the surplus power, and the actual total energy consumption reaches 110% of the surplus power, the flexible on / off energy consumption submodule is controlled to be shut off. The steps include controlling the system to reactivate the flexible on / off energy consumption submodule when the actual total energy consumption is less than the surplus power, and the actual total energy consumption reaches 90% of the surplus power, The receiving end AC fault ride-through control method according to claim 6, characterized by including the following:

8. In response to receiving a fault recovery signal transmitted by a receiving end converter station that experienced an AC fault after the fault was recovered, the steps include sequentially controlling the shutdown of the switched-on AC energy-consuming submodules according to the shutdown speed, The receiving end AC fault ride-through control method according to claim 6, further comprising the following:

9. The tripping process involves obtaining the power-up rate at the receiving end converter station after the fault is recovered, and calculating the tripping time interval using the following formula: [Math 2] Here, T is the time interval during which the AC energy consumption device shuts off one group of AC energy consumption submodules, f is the surplus power value, and L is the rate at which the receiving end converter increases power after fault recovery. [Math 3] This involves a step indicating the actual number of groups of AC energy consumption submodules that are used in the AC energy consumption device, A step of controlling the tripping speed to be the same as the raising speed, or the error between the tripping speed and the raising speed to be within a preset error speed range, based on the tripping time interval. The receiving end AC fault ride-through control method according to claim 8, further comprising the following:

10. A method for controlling AC fault ride-through at the receiving end, Applied to the multi-terminal power transmission system of the new energy island grid, The multi-terminal power transmission system includes at least an AC energy consumption device and at least one transmission end converter connected to the AC energy consumption device, each of the transmission end converters being connected to at least two receiving end converters, and the method is, The steps include: determining the receiving end converter that detected the occurrence of an AC fault as the faulty receiving end converter; generating an AC voltage fault signal using the faulty receiving end converter; and simultaneously performing a power surplus evaluation to obtain a surplus power value; The steps include: transmitting the AC voltage fault signal and the surplus power value to the AC energy consumption device using the fault receiving terminal converter; If the fault receiving end converter station is a receiving end constant voltage station, the steps include: turning on the AC energy consumption device to absorb the surplus power of the island grid based on the AC voltage fault signal and the surplus power value; If the faulty receiving end converter is a receiving end constant power station, the faulty receiving end converter adjusts the power reference value of the faulty receiving end converter based on the surplus power value, and activates the AC energy consumption device to absorb the surplus power of the island grid. A method for controlling AC fault ride-through at the receiving end, characterized by including the following:

11. The step of performing a power surplus assessment and obtaining a surplus power value is: The step includes calculating the surplus power value corresponding to the faulty power receiving end converter using the following formula: [Math 4] Here, f is the surplus power value, V ｍ＿ａｆ This is the effective value of the AC voltage after the fault occurs, V ｍ＿ｐｒｅ This is the effective value of the AC voltage before the fault occurred, P ｐｒｅ This is the active power before the failure occurred. The AC fault ride-through control method for the receiving end according to claim 10, characterized by the features described above.

12. The AC energy consumption device includes multiple groups of AC energy consumption submodules, each of which corresponds to one AC energy consumption capacity. The step of turning on the AC energy consumption device to absorb the surplus power of the island grid based on the AC voltage fault signal and the surplus power value is as follows: Based on the AC voltage fault signal, the number of groups of AC energy consumption submodules to be switched on is calculated using the AC energy consumption capacity and the surplus power value, and when switching on the corresponding number of AC energy consumption submodules to absorb the surplus power of the island grid, the number of groups to be switched on is rounded up. In the process of absorbing surplus power, the AC energy consumption device acquires the actual total energy consumption, and if the actual total energy consumption is greater than the surplus power, the AC energy consumption device selects one group of AC energy consumption submodules from the multiple groups of AC energy consumption submodules as a flexible on / off energy consumption submodule, wherein the flexible on / off energy consumption submodule is used to control the difference between the actual total energy consumption and the actual fault surplus power to be kept within ±10%. The receiving end AC fault ride-through control method according to claim 11, characterized by including the following:

13. The step of controlling the difference between the actual total energy consumption and the actual fault surplus power to be kept within ±10% is: In the process of absorbing surplus power, if the actual total energy consumption is greater than the surplus power, and the actual total energy consumption reaches 110% of the surplus power, the AC energy consumption device is controlled to shut off the flexible on / off energy consumption submodule. The steps include: when the actual total energy consumption is less than the surplus power, and the actual total energy consumption reaches 90% of the surplus power, the AC energy consumption device controls the flexible on / off energy consumption submodule to re-energize; The receiving end AC fault ride-through control method according to claim 12, characterized by including the following:

14. When it is detected that the AC voltage of the faulty power receiving terminal converter has recovered to a preset AC voltage threshold, the faulty power receiving terminal converter generates a fault recovery signal and transmits the fault recovery signal to the AC energy consumption device. Based on the fault recovery signal, the AC energy consumption device sequentially controls the switching-on AC energy consumption submodules according to the switching speed. If the faulty receiving end converter is a receiving end constant power station, the further step is to raise the power reference value of the faulty receiving end converter to the power before the fault occurred, according to the rate of increase. The receiving end AC fault ride-through control method according to claim 12, further comprising the above.

15. The interruption process involves the step of calculating the interruption time interval of the AC energy consumption device using the following formula: [Math 5] Here, T is the time interval during which the AC energy consumption device shuts off one group of AC energy consumption submodules, and L is the rate at which the receiving end converter increases power after a fault recovery. [Math 6] This involves a step indicating the actual number of groups of AC energy consumption submodules that are used in the AC energy consumption device, Based on the aforementioned interruption time interval, the AC energy consumption device controls the interruption speed so that the interruption speed is the same as the raising speed, or so that the error between the interruption speed and the raising speed is within a preset error speed range. If the faulty receiving end converter is a receiving end constant power station, the steps include: controlling the faulty receiving end converter to perform a power increase operation after a predetermined communication delay to synchronize with the energy consumption cutoff operation by the AC energy consumption device; The receiving end AC fault ride-through control method according to claim 14, further comprising the above.

16. All transmission end converters employ a double-closed-loop AC constant voltage-frequency control system, and for at least two receiving end converters corresponding to each transmission end converter, one receiving end converter employs a constant DC voltage control system, and the remaining receiving end converters employ a constant power control system. The receiving end AC fault ride-through control method according to any one of claims 1 to 15.

17. A receiving-end AC fault ride-through control device, It is applied to the receiving end converter station of the multi-terminal power transmission system of the new energy island grid. The multi-terminal power transmission system further includes an AC energy consumption device and at least one transmission end converter connected to the AC energy consumption device, each of the transmission end converters being connected to at least two receiving end converters, and the device is When an AC fault is detected, a first power surplus evaluation module generates an AC voltage fault signal and simultaneously performs a power surplus evaluation to obtain a surplus power value. A first surplus power value transmission module transmits the AC voltage fault signal and the surplus power value to the AC energy consumption device so that the AC energy consumption device is activated based on the AC voltage fault signal and the surplus power value to absorb the island grid voltage surplus power. Currently, when using a constant power control method, a power reference value adjustment module is also used to adjust the power reference value based on the surplus power value. A receiving-end AC fault ride-through control device characterized by including the following:

18. A receiving-end AC fault ride-through control device, Applicable to AC energy consumption devices in the multi-terminal power transmission system of the new energy island grid, The multi-terminal power transmission system further includes at least one transmission end converter connected to the AC energy consumption device, each of the transmission end converters being connected to at least two receiving end converters, and the device is A surplus power value receiving module that receives AC voltage fault signals and surplus power values ​​transmitted from a power receiving terminal converter station where an AC fault has occurred, A surplus power input module controls the input of surplus power to absorb the island grid based on the AC voltage fault signal and the surplus power value, A receiving-end AC fault ride-through control device characterized by including the following:

19. A receiving-end AC fault ride-through control device, Applied to the multi-terminal power transmission system of the new energy island grid, The multi-terminal power transmission system includes at least an AC energy consumption device and at least one transmission end converter connected to the AC energy consumption device, each of the transmission end converters being connected to at least two receiving end converters, and the device is A second power surplus evaluation module determines a power receiving end converter station where an AC fault is detected as a faulty power receiving end converter station, generates an AC voltage fault signal using the faulty power receiving end converter station, and simultaneously performs a power surplus evaluation to obtain a surplus power value. The fault receiving terminal converter transmits the AC voltage fault signal and the surplus power value to the AC energy consumption device via a surplus power value second transmission module, When the faulty receiving end converter station is a receiving end constant voltage station, a receiving end constant voltage station control processing module activates the AC energy consumption device to absorb the surplus power of the island grid based on the AC voltage fault signal and the surplus power value, When the faulty receiving end converter is a receiving end regulating power station, the receiving end regulating power station control processing module adjusts the power reference value of the faulty receiving end converter based on the surplus power value and activates the AC energy consumption device to absorb the surplus power of the island grid, A receiving-end AC fault ride-through control device characterized by including the following:

20. An electronic device including a processor and memory, The memory stores program code and transmits the program code to the processor. The processor executes the receiving end AC fault ride-through control method according to any one of claims 1 to 16 based on the instructions in the program code. An electronic device characterized by the following features.

21. A computer-readable storage medium, A program code for executing the AC fault ride-through control method for the receiving end according to any one of claims 1 to 16 is stored. A computer-readable storage medium characterized by the following features.

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