Reactive power automatic recovery control method and system suitable for wind and light power storage station

Abstract

The reactive automatic recovery control method comprises the following steps: acquiring a difference value between a reactive real-time value of a grid-connected point and a reactive instruction target value of the wind and light power storage station, and judging whether a reactive load of the wind and light power storage station changes suddenly or not; when the reactive load of the wind and light power storage station changes suddenly, predicting whether the bus voltage of each voltage level is safe or not in the scene that the reactive real-time value of the grid-connected point reaches the reactive instruction target value of the wind and light power storage station; when the reactive load of the wind and light power storage station changes suddenly and the bus voltage of each voltage level is not safe under the condition that the reactive real-time value of the grid-connected point reaches the reactive instruction target value of the wind and light power storage station, reactive instruction target value recovery is executed according to the operation condition of the wind and light power storage station, so that the harm caused by the reactive impact of the power grid is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy power generation control, and specifically, relates to a reactive power automatic recovery control method and system applicable to a wind-solar-storage power station. Background Art

[0002] With the global energy structure accelerating its transformation towards renewable energy, new energy power stations have become an important part of the power system. However, the high proportion of new energy grid connection has led the power grid to face challenges such as severe reactive power fluctuations and poor voltage stability. Therefore, reactive power automatic recovery control technology has become a key means to ensure the safe and economic operation of the power grid.

[0003] In the prior art, for the optimized dispatching method of a distribution network with wind-solar-storage coordination, when it is determined that the distribution network has insufficient power supply based on the planned power supply on the source side within a day and the actual power supply on the source side within a day, type B incentive-based demand response is adopted for power consumption dispatching to achieve load balance and peak shaving and valley filling of the distribution network; when it is determined that the distribution network has excessive power supply based on the planned power supply on the source side within a day and the actual power supply on the source side within a day, redundant electric energy is stored, taking into account both load balance and the utilization efficiency of power resources. However, this method adopts type B incentive-based demand response based on the planned power supply and actual power supply of the wind-solar-storage power station to achieve load balance, adjusts the load through a user-side agreement, and the actual dispatching instruction execution delay can reach 15 - 30 minutes, making it difficult to handle the minute-level fluctuations of wind and solar power generation, and it only considers the influence of active power. The present invention makes corresponding recovery corrections for the reactive power fluctuations of the wind-solar-storage power station to cope with the impact of grid reactive power shocks; for the reactive power compensation control method of the distribution network, it ensures that large power plants can provide sufficient active power heat reserve for the load center, meets the demand for reactive power voltage support, forms sufficient reactive power reserve capacity at each load node and hub node during the operation of the power system, avoids the occurrence of malignant events such as voltage collapse caused by the lack of reactive power in the system, and ensures the safe and stable operation of the power grid. After the equipment operation encounters a power loss situation, the capacitor operation is withdrawn in a timely manner to ensure data integrity within a certain time interval and effectively avoid the adverse effects on the equipment in the case of power loss. During the actual operation of the distribution network system, the sampling interval is adjusted in real time to ensure the accuracy of information sampling and analysis. However, this method does not consider the situation of wind-solar-storage power stations such as wind-solar-storage power stations, its response speed and dynamic adjustment ability are insufficient, and there is a 5 - 10 minute-level regulation dead zone for the switching of fixed capacitor banks, which is not enough to cope with the second-level reactive power fluctuations brought by new energy access. The present invention can dynamically adapt to the changes in new energy loads and achieve fast reactive power regulation for the reactive power fluctuations that may cause grid risks in wind-solar-storage power stations. Summary of the Invention

[0004] To address the deficiencies in the existing technologies, the present invention provides a reactive power automatic recovery control method and system applicable to a wind-solar-storage power station. According to the possible grid disconnection situations at the power station, the reactive power control target values of the fan energy management platform, photovoltaic data acquisition, and energy storage EMS in the wind-solar-storage power station are automatically recovered and corrected, thereby reducing the harm caused by reactive power shocks to the power grid.

[0005] The present invention adopts the following technical solutions.

[0006] The present invention proposes a reactive power automatic recovery control method applicable to a wind-solar-storage power station, including:

[0007] Obtain the difference between the real-time reactive power value at the grid connection point and the reactive power command target value of the wind-solar-storage power station, and determine whether the reactive power load of the wind-solar-storage power station has changed suddenly;

[0008] When the reactive power load of the wind-solar-storage power station changes suddenly, predict whether the bus voltages of each voltage level are safe in the scenario where the real-time reactive power value at the grid connection point reaches the reactive power command target value of the wind-solar-storage power station;

[0009] When the reactive power load of the wind-solar-storage power station changes suddenly and the bus voltages of each voltage level are predicted to be unsafe in the scenario where the real-time reactive power value at the grid connection point reaches the reactive power command target value of the wind-solar-storage power station, perform the recovery of the reactive power command target value according to the operating conditions of the wind-solar-storage power station.

[0010] Obtain the difference between the real-time reactive power value at the grid connection point and the reactive power command target value of the wind-solar-storage power station as the reactive power deviation ΔQ;

[0011] When |ΔQ|>Q0 and ΔQ<0, it is determined that the reactive power load of the wind-solar-storage power station has changed suddenly; when |ΔQ|≤Q0 and ΔQ>0, it is determined that the reactive power load of the wind-solar-storage power station has not changed suddenly; where Q0 is the critical value of reactive power change.

[0012] The value of the critical value of reactive power change is 2000 kVar.

[0013] Use the reactive power deviation ΔQ and the short-circuit capacity of each voltage level to estimate the voltage fluctuation amplitude of the busbars of each voltage level, satisfying the following relationship:

[0014]

[0015] In the formula, ΔV H 、ΔV L are the voltage fluctuation amplitudes of the high-voltage side busbar and the low-voltage side busbar respectively, and S H 、S L are the short-circuit capacities of the high-voltage side and the low-voltage side respectively.

[0016] When then it is determined that the high-voltage side busbar is operating safely, when If so, it is determined that the high-voltage side bus is operating unsafely, where is the safety value of the voltage fluctuation amplitude of the high-voltage side bus, and its value is 0.02 times the rated voltage of the high-voltage side bus;

[0017] When If so, it is determined that the low-voltage side bus is operating safely. When If so, it is determined that the low-voltage side bus is operating unsafely, where is the safety value of the voltage fluctuation amplitude of the low-voltage side bus, and its value is 0.02 times the rated voltage of the low-voltage side bus.

[0018] Taking the sum of the real-time operating voltage and the voltage fluctuation amplitude of each voltage-level bus as the voltage target value of each voltage-level bus under the scenario that the real-time reactive power value at the grid connection point reaches the reactive power command target value of the wind-solar-storage power station, the following relational expression is satisfied:

[0019]

[0020] In the formula, are the voltage target values of the high-voltage side bus and the low-voltage side bus respectively, in V H and V L are the real-time operating voltages of the high-voltage side bus and the low-voltage side bus respectively.

[0021] When If so, it is determined that the voltage of the high-voltage side bus is safe when the reactive power load of the wind-solar-storage power station suddenly changes; when If so, it is determined that the voltage of the high-voltage side bus is unsafe when the reactive power load of the wind-solar-storage power station suddenly changes; where is the upper limit value of the safe operating voltage range of the high-voltage side bus of the power grid, and its value is 1.05 - 1.07 times the rated voltage of the high-voltage side bus, is the lower limit value of the safe operating voltage range of the high-voltage side bus of the power grid, and its value is 0.95 - 0.97 times the rated voltage of the high-voltage side bus, and the sum of the absolute values of the positive and negative deviations of the bus operating voltage does not exceed 10%.

[0022] When If so, it is determined that the voltage of the low-voltage side bus is safe when the reactive power load of the wind-solar-storage power station suddenly changes; when If so, it is determined that the voltage of the low-voltage side bus is unsafe when the reactive power load of the wind-solar-storage power station suddenly changes; where is the upper limit value of the safe operating voltage range of the low-voltage side bus of the power grid, and its value is 1.05 - 1.07 times the rated voltage of the low-voltage side bus, is the lower limit value of the safe operating voltage range of the low-voltage side bus of the power grid, and its value is 0.95 - 0.97 times the rated voltage of the low-voltage side bus, and the sum of the absolute values of the positive and negative deviations of the bus operating voltage does not exceed 10%.

[0023] According to the operating conditions of the wind-solar-storage power station, the recovery of the reactive power command target value is performed, including:

[0024] For the wind farm, the recovery of the reactive power command target value is to correct the reactive power command target value to the real-time reactive power value at the grid connection point; for the photovoltaic power station, when the inverter enters the shutdown state, the recovery of the reactive power command target value is to correct the reactive power command target value to 0 kVar; for the energy storage power station, the recovery of the reactive power command target value is to correct the reactive power command target value to the real-time reactive power value at the grid connection point.

[0025] The present invention also provides a reactive power automatic recovery control system applicable to a wind-solar-storage power station, including:

[0026] A reactive power mutation detection module, which is used to obtain the difference between the real-time reactive power value at the grid connection point and the reactive power command target value of the wind-solar-storage power station, and judge whether the reactive power load of the wind-solar-storage power station has changed suddenly;

[0027] A bus voltage safety assessment module, which is used to predict whether the bus voltages of each voltage level are safe when the real-time reactive power value at the grid connection point reaches the reactive power command target value of the wind-solar-storage power station when the reactive power load of the wind-solar-storage power station changes suddenly;

[0028] A recovery strategy execution module, which is used to execute the recovery of the reactive power command target value according to the operating conditions of the wind-solar-storage power station when the reactive power load of the wind-solar-storage power station changes suddenly and the bus voltages of each voltage level are predicted to be unsafe when the real-time reactive power value at the grid connection point reaches the reactive power command target value of the wind-solar-storage power station.

[0029] The present invention is also a terminal, including a processor and a storage medium; the storage medium is used to store instructions; the processor is used to operate according to the instructions to execute the steps of the method.

[0030] The present invention is also a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, the steps of the method are realized.

[0031] The beneficial effects of the present invention are at least as follows compared with the prior art. The present invention adopts a three-stage multi-dimensional logic judgment mechanism composed of reactive power mutation judgment, voltage safe operation range judgment, and scenario-based recovery strategy judgment, realizing more refined control; by accurately judging the reactive power mutation and voltage fluctuation trend, quickly adjusting the reactive power target value, effectively suppressing the voltage fluctuations of the high-voltage side and low-voltage side buses, preventing them from exceeding the safe operation range, and improving voltage stability. Moreover, through hierarchical logic judgment, reactive power mutation detection → voltage safety assessment → recovery strategy execution, the generation time of control commands is shortened, and the response efficiency of the wind-solar-storage power station to emergencies is improved.

[0032] The method proposed by the present invention comprehensively considers the reactive power regulation capabilities of wind power, photovoltaics, and energy storage, realizes the dynamic optimal allocation of reactive power resources within the power station, further reduces the voltage fluctuation range, and improves the voltage qualification rate of the power station. It prevents the reactive power equipment in the power station from being disconnected and reconnected within a short period of time, the voltage fluctuations generated by the power station when executing reactive power commands, and avoids the possible risk of grid voltage instability. Description of the Drawings

[0033] Figure 1 is a flowchart of the automatic reactive power recovery control method applicable to a wind-solar-storage power station proposed by the present invention. Detailed Embodiments

[0034] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. The embodiments described in this application are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the spirit of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0035] The present invention proposes an automatic reactive power recovery control method applicable to a wind-solar-storage power station, as Figure 1 shown, including:

[0036] Step 1: Obtain the difference between the real-time reactive power value at the grid connection point and the reactive power command target value of the wind-solar-storage power station, and determine whether the reactive power load of the wind-solar-storage power station has changed suddenly.

[0037] Specifically, Step 1 includes:

[0038] Step 1.1: Obtain the difference between the real-time reactive power value Q at the grid connection point and the reactive power command target value Q * of the wind-solar-storage power station as the reactive power deviation ΔQ;

[0039] Step 1.2: When |ΔQ| > Q0 and ΔQ < 0, it is determined that the reactive power load of the wind-solar-storage power station has changed suddenly; when |ΔQ| ≤ Q0 and ΔQ > 0, it is determined that the reactive power load of the wind-solar-storage power station has not changed suddenly; where Q0 is the critical value of reactive power sudden change;

[0040] In the embodiment, the value of the critical value Q0 of reactive power sudden change is 2000 kVar.

[0041] The present invention proposes to conduct a logical judgment on whether the reactive power load of the wind-solar-storage power station has changed suddenly to determine whether the reactive power load of the wind-solar-storage power station has changed deviated from the reactive power command target value within a very short period of time; when the reactive power load changes suddenly, it may be necessary to recover the reactive power command, that is, to correct the reactive power command target value of the wind-solar-storage power station.

[0042] Step 2: When the reactive power load of the wind-solar-storage power station suddenly changes, predict whether the bus voltages at each voltage level are safe under the scenario where the real-time reactive power value at the grid connection point reaches the reactive power command target value of the wind-solar-storage power station.

[0043] Specifically, Step 2 includes:

[0044] Step 2.1: Estimate the voltage fluctuation amplitudes of the buses at each voltage level by using the reactive power deviation ΔQ and the short-circuit capacities of each voltage level, satisfying the following relational expression:

[0045]

[0046] In the formula, ΔV H and ΔV L are the voltage fluctuation amplitudes of the high-voltage side bus and the low-voltage side bus respectively, and S H and S L are the short-circuit capacities of the high-voltage side and the low-voltage side respectively;

[0047] In the embodiment, generally, the low-voltage side voltage level of the wind-solar-storage power station is 10 kV or 35 kV; for the high-voltage side bus voltage level: for small-capacity power stations (≤8 MW), the 10 kV or 35 kV high-voltage side voltage is usually selected; for medium-capacity power stations (8 MW - 50 MW), the 35 kV or 66 kV voltage level is mostly adopted; for large-capacity power stations (≥50 MW), they need to be connected to the high-voltage power grid of 110 kV and above (such as 220 kV, 330 kV). It should be noted that small-capacity power stations usually have no main transformers, and in this case, it is considered that there is only a high-voltage side bus in the power station and no low-voltage side bus.

[0048] Estimating the voltage fluctuation based on the short-circuit capacity realizes calculating the target voltage by combining the short-circuit capacity and real-time data, improving the accuracy of voltage fluctuation prediction; obtaining the deviation of the reactive power target by real-time monitoring of the short-circuit capacity, dynamically adjusting the reactive power command, avoiding the risk of voltage over-limit caused by hysteresis in traditional technologies, reducing misjudgment caused by model simplification or empirical parameters, and reducing the impact of grid reactive power surges on equipment.

[0049] Step 2.2: When the voltage fluctuation amplitude of the bus at each voltage level is greater than the corresponding bus voltage fluctuation amplitude safety value, it is determined that there is a risk for the bus voltages at each voltage level; otherwise, it is determined that the bus voltages at each voltage level are safe;

[0050] When , it is determined that the high-voltage side bus is operating safely, and when , it is determined that the high-voltage side bus is operating unsafely, where is the voltage fluctuation amplitude safety value of the high-voltage side bus, and its value is 0.02 times the rated voltage of the high-voltage side bus;

[0051] When If so, it is determined that the low-voltage side bus operates safely. When If so, it is determined that the low-voltage side bus does not operate safely. Among them, is the safety value of the voltage fluctuation amplitude of the low-voltage side bus, and the value is 0.02 times the rated voltage of the low-voltage side bus;

[0052] Step 2.3: Take the sum of the real-time operating voltage and the voltage fluctuation amplitude of each voltage level bus as the voltage target value of each voltage level bus when the real-time reactive power value at the grid connection point reaches the reactive power command target value of the wind-solar-storage power station;

[0053] The voltage target values of each voltage level bus satisfy the following relational expressions:

[0054]

[0055] In the formula, are the voltage target values of the high-voltage side bus and the low-voltage side bus respectively, in V H and V L are the real-time operating voltages of the high-voltage side bus and the low-voltage side bus respectively;

[0056] Step 2.4: When it is determined that there is a risk in the voltage of each voltage level bus, if the voltage target value of each voltage level bus is within the safe operating voltage range, it is determined that the voltage of each voltage level bus is safe when the reactive power load of the wind-solar-storage power station undergoes a sudden change; otherwise, it is determined that the voltage of each voltage level bus is not safe when the reactive power load of the wind-solar-storage power station undergoes a sudden change;

[0057] When If so, it is determined that the voltage of the high-voltage side bus is safe when the reactive power load of the wind-solar-storage power station undergoes a sudden change; when If so, it is determined that the voltage of the high-voltage side bus is not safe when the reactive power load of the wind-solar-storage power station undergoes a sudden change; among them, is the upper limit value of the safe operating voltage range of the grid high-voltage side bus, and the value is 1.05 - 1.07 times the rated voltage of the high-voltage side bus, is the lower limit value of the safe operating voltage range of the grid high-voltage side bus, and the value is 0.95 - 0.97 times the rated voltage of the high-voltage side bus, and the sum of the absolute values of the positive and negative deviations of the bus operating voltage does not exceed 10%;

[0058] When If so, it is determined that the voltage of the low-voltage side bus is safe when the reactive power load of the wind-solar-storage power station undergoes a sudden change; when If so, it is determined that the voltage of the low-voltage side bus is not safe when the reactive power load of the wind-solar-storage power station undergoes a sudden change; among them, is the upper limit value of the safe operating voltage range of the grid low-voltage side bus, and the value is 1.05 - 1.07 times the rated voltage of the low-voltage side bus, is the lower limit value of the safe operating voltage range of the low-voltage side bus of the power grid, and its value is 0.95 to 0.97 times the rated voltage of the low-voltage side bus, and the sum of the absolute values of the positive and negative deviations of the bus operating voltage does not exceed 10%.

[0059] Step 2 previews the bus voltage conditions in the substation when the real-time reactive power value reaches the reactive power command target value. Based on two different bus voltage safety criteria, it realizes the identification of whether the target voltages of the high- and low-voltage side buses of the power grid exceed the safe operating range when the reactive power actual value reaches the reactive power command target value in the case of reactive power mutation in the wind-solar-storage power station and subsequent grid connection scenarios of wind turbines, inverters, energy storage units, etc., and can more accurately identify whether reactive power fluctuations will pose risks to the power grid voltage, so as to recover and correct the reactive power commands that may cause risks.

[0060] Step 3, when the reactive power load of the wind-solar-storage power station mutates and it is predicted that the bus voltages of each voltage level are unsafe in the scenario where the real-time reactive power value at the grid connection point reaches the reactive power command target value of the wind-solar-storage power station, the reactive power command target value is recovered according to the operating conditions of the wind-solar-storage power station.

[0061] Recovering the reactive power command target value according to the operating conditions of the wind-solar-storage power station includes:

[0062] For the wind farm, the reactive power command target value will be automatically recovered and corrected to the real-time reactive power value at the grid connection point; for the photovoltaic power station, considering the situation of photovoltaic disconnection from the grid at night, when the light intensity at night drops to a certain value, the inverter is in the critical state of starting and stopping, and when the system identifies that the inverter enters the shutdown state, the reactive power command target value will be automatically recovered and corrected to 0 kVar; for the energy storage power station, the reactive power command target value will be automatically recovered and corrected to the real-time reactive power value at the grid connection point. A differentiated reactive power target value correction strategy is designed for the different operating characteristics of the wind farm, photovoltaic power station and energy storage power station, such as photovoltaic disconnection from the grid at night and dynamic response of energy storage, improving the adaptability; by automatically switching the reactive power target value correction strategy, the flexibility and reliability of reactive power control are ensured.

[0063] The above reactive power control recovery strategy under different scenario conditions corrects the system reactive power control target value according to the safe operating range of the wind-solar-storage power station under different scenarios and conditions, and is a reactive power recovery strategy for judging the new energy power station under different scenario conditions to ensure the safety of the power grid when reactive power may cause voltage fluctuations to exceed the safe range.

[0064] The present invention also proposes a reactive power automatic recovery control system applicable to a wind-solar-storage power station, including:

[0065] A reactive power mutation detection module, which is used to obtain the difference between the real-time reactive power value at the grid connection point and the reactive power command target value of the wind-solar-storage power station, and judge whether the reactive power load of the wind-solar-storage power station has mutated;

[0066] The bus voltage safety assessment module is used to predict whether the bus voltages at each voltage level are safe when the reactive power real-time value at the grid connection point reaches the reactive power command target value of the wind-solar-storage power station in the scenario where the reactive power load of the wind-solar-storage power station suddenly changes.

[0067] The recovery strategy execution module is used to execute the recovery of the reactive power command target value according to the operating conditions of the wind-solar-storage power station when the reactive power load of the wind-solar-storage power station suddenly changes and the bus voltages at each voltage level are unsafe when it is predicted that the reactive power real-time value at the grid connection point reaches the reactive power command target value of the wind-solar-storage power station.

[0068] The present disclosure may be a system, a method, and / or a computer program product. The computer program product may include a computer-readable storage medium having thereon computer-readable program instructions for causing a processor to implement various aspects of the present disclosure.

[0069] The computer-readable storage medium may be a tangible device that can retain and store instructions for use by an instruction execution device. The computer-readable storage medium may be, for example, but is not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer-readable storage medium include: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disc (DVD), a memory stick, a floppy disk, a mechanically encoded device such as a punched card or raised structures in grooves having instructions stored thereon, and any suitable combination of the foregoing. The computer-readable storage medium as used herein is not construed as an instantaneous signal itself, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagated through a waveguide or other transmission medium (e.g., an optical pulse through an optical fiber cable), or an electrical signal transmitted through a wire.

[0070] The computer-readable program instructions described herein may be downloaded from the computer-readable storage medium to various computing / processing devices, or downloaded to an external computer or external storage device through a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network may include a copper transmission cable, an optical fiber transmission, a wireless transmission, a router, a firewall, a switch, a gateway computer, and / or an edge server. The network adapter or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions for storage in the computer-readable storage medium in each computing / processing device.

[0071] The computer program instructions for performing the operations of the present disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state-setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages such as Smalltalk, C++, etc., and conventional procedural programming languages such as the "C" language or similar programming languages. The computer-readable program instructions may be executed entirely on the user's computer, partially on the user's computer, executed as a stand-alone software package, partially on the user's computer and partially on a remote computer, or entirely on the remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or it may be connected to an external computer (e.g., by using an Internet service provider to connect through the Internet). In some embodiments, by using the state information of the computer-readable program instructions to customize an electronic circuit, such as a programmable logic circuit, a field-programmable gate array (FPGA), or a programmable logic array (PLA), the electronic circuit can execute the computer-readable program instructions to implement various aspects of the present disclosure.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications or equivalent replacements can still be made to the specific embodiments of the present invention, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention should be covered by the protection scope of the claims of the present invention.

Claims

1. A reactive power automatic recovery control method applicable to a wind-solar-storage power station, characterized in that Including: Obtain the difference between the real-time reactive power value at the grid connection point and the reactive power command target value of the wind-solar-storage power station, and determine whether the reactive power load of the wind-solar-storage power station has changed suddenly; When the reactive power load of the wind-solar-storage power station changes suddenly, predict whether the bus voltages at each voltage level are safe under the scenario where the real-time reactive power value at the grid connection point reaches the reactive power command target value of the wind-solar-storage power station; When the reactive power load of the wind-solar-storage power station changes suddenly, and it is predicted that the bus voltages at each voltage level are not safe under the scenario where the real-time reactive power value at the grid connection point reaches the reactive power command target value of the wind-solar-storage power station, perform the recovery of the reactive power command target value according to the operating conditions of the wind-solar-storage power station.

2. The automatic reactive power recovery control method applicable to a wind-solar-storage power station according to claim 1, characterized in that Obtain the difference between the real-time reactive power value at the grid connection point and the reactive power command target value of the wind-solar-storage power station as the reactive power deviation ΔQ; When |ΔQ| > Q0 and ΔQ < 0, it is determined that the reactive power load of the wind-solar-storage power station has changed suddenly; when |ΔQ| ≤ Q0 and ΔQ > 0, it is determined that the reactive power load of the wind-solar-storage power station has not changed suddenly; where Q0 is the critical value of reactive power change.

3. The automatic reactive power recovery control method applicable to a wind-solar-storage power station according to claim 2, characterized in that The value of the critical value of reactive power change is 2000 kVar.

4. The automatic reactive power recovery control method applicable to a wind-solar-storage power station according to claim 2, characterized in that Use the reactive power deviation ΔQ and the short-circuit capacity of each voltage level to estimate the voltage fluctuation amplitude of the bus at each voltage level, satisfying the following relationship: where, ΔV H , ΔV L are the voltage fluctuation amplitudes of the high-voltage side bus and the low-voltage side bus respectively, and S H , S L are the short-circuit capacities of the high-voltage side and the low-voltage side respectively.

5. The automatic reactive power recovery control method applicable to a wind-solar-storage power station according to claim 4, characterized in that When it is determined that the high-voltage side bus operates safely. When it is determined that the high-voltage side bus does not operate safely. Among them, is the safety value of the voltage fluctuation amplitude of the high-voltage side bus, and its value is 0.02 times the rated voltage of the high-voltage side bus; When it is the case, it is determined that the low-voltage side bus operates safely. When it is the case, it is determined that the low-voltage side bus does not operate safely. Among them, is the safety value of the voltage fluctuation amplitude of the low-voltage side bus, and the value is 0.02 times the rated voltage of the low-voltage side bus.

6. The automatic reactive power recovery control method applicable to a wind-solar-storage power station according to claim 5, characterized in that Take the sum of the real-time operating voltage value of the bus at each voltage level and the voltage fluctuation amplitude as the voltage target value of the bus at each voltage level under the scenario where the real-time reactive power value at the grid connection point reaches the reactive power command target value of the wind-solar-storage power station, satisfying the following relationship: In the formula, are the voltage target values of the high-voltage side bus and the low-voltage side bus, respectively, in V H , V L are the real-time operating voltages of the high-voltage side bus and the low-voltage side bus, respectively.

7. The automatic reactive power recovery control method applicable to a wind-solar-storage power station according to claim 6, characterized in that When , it is determined that the bus voltage on the high-voltage side is safe when the reactive power load of the wind-solar-storage power station suddenly changes; when , it is determined that the bus voltage on the high-voltage side is unsafe when the reactive power load of the wind-solar-storage power station suddenly changes; among them, is the upper limit value of the safe operating voltage range of the grid high-voltage side bus, and its value is 1.05 - 1.07 times the rated voltage of the high-voltage side bus, is the lower limit value of the safe operating voltage range of the grid high-voltage side bus, and its value is 0.95 - 0.97 times the rated voltage of the high-voltage side bus, and the sum of the absolute values of the positive and negative deviations of the bus operating voltage does not exceed 10%.

8. The automatic reactive power recovery control method applicable to a wind-solar-storage power station according to claim 6, characterized in that When is satisfied, it is determined that the low-voltage side bus voltage is safe when the reactive power load of the wind-solar-storage power station suddenly changes; when is satisfied, it is determined that the low-voltage side bus voltage is unsafe when the reactive power load of the wind-solar-storage power station suddenly changes; where is the upper limit value of the safe operating voltage range of the low-voltage side bus of the power grid, and its value is 1.05 to 1.07 times the rated voltage of the low-voltage side bus, is the lower limit value of the safe operating voltage range of the low-voltage side bus of the power grid, and its value is 0.95 to 0.97 times the rated voltage of the low-voltage side bus, and the sum of the absolute values of the positive and negative deviations of the bus operating voltage does not exceed 10%.

9. The automatic reactive power recovery control method applicable to a wind-solar-storage power station according to claim 1, characterized in that Performing the recovery of the reactive power command target value according to the operating conditions of the wind-solar-storage power station includes: For a wind farm, the recovery of the reactive power command target value is to correct the reactive power command target value to the real-time reactive power value at the grid connection point; for a photovoltaic power station, when the inverter enters the shutdown state, the recovery of the reactive power command target value is to correct the reactive power command target value to 0 kVar; for an energy storage power station, the recovery of the reactive power command target value is to correct the reactive power command target value to the real-time reactive power value at the grid connection point.

10. A reactive power automatic recovery control system applicable to a wind-solar-storage power station, which implements the method according to any one of claims 1 to 9, characterized in that, Including: A reactive power mutation detection module, configured to obtain the difference between the real-time reactive power value at the grid connection point and the reactive power command target value of the wind-solar-storage power station, and determine whether the reactive power load of the wind-solar-storage power station has changed suddenly; The bus voltage safety assessment module is used to predict whether the bus voltages of each voltage level are safe in the scenario where the reactive power real-time value at the grid connection point reaches the reactive power command target value of the wind-solar-storage power station when the reactive power load of the wind-solar-storage power station suddenly changes; The recovery strategy execution module is used to execute the recovery of the reactive power command target value according to the operating conditions of the wind-solar-storage power station when the reactive power load of the wind-solar-storage power station suddenly changes and the bus voltages of each voltage level are unsafe in the scenario where the reactive power real-time value at the grid connection point reaches the reactive power command target value of the wind-solar-storage power station.

11. A terminal, comprising a processor and a storage medium; characterized in that: The storage medium is used to store instructions; The processor is used to operate according to the instructions to execute the steps of the method according to any one of claims 1-9.

12. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, the steps of the method according to any one of claims 1-9 are implemented.

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