A reactive power adaptive voltage regulation method and device for distributed photovoltaic grid connection

Abstract

The present application relates to the field of new energy grid connection technology, and specifically provides a reactive power adaptive voltage regulation method and device for distributed photovoltaic grid connection, comprising: obtaining a comparison result of a PCC point voltage of a photovoltaic grid-connected inverter and a voltage threshold value; determining an active instruction correction value and a reactive instruction correction value based on the comparison result; generating an SPWM driving signal for regulating the photovoltaic grid-connected inverter by using the active instruction correction value and the reactive instruction correction value, and controlling the photovoltaic grid-connected inverter to complete voltage regulation. The technical scheme provided by the present application realizes the unified exertion of active output control of the photovoltaic inverter, utilization of the remaining reactive power capacity, adaptive correction of the voltage reference, and island auxiliary identification.

Description

Technical Field

[0001] This invention relates to the field of new energy grid connection technology, specifically to a reactive power adaptive voltage regulation method and device for distributed photovoltaic grid connection. Background Technology In recent years, with the continuous advancement of the construction of new power systems, the installed capacity of photovoltaic power generation has grown rapidly, and distributed photovoltaic power has become an important form of new energy access on the distribution network side.

[0002] Distributed photovoltaic (PV) systems are mostly connected to low-voltage distribution areas or the ends of power lines, characterized by dispersed connection points, significant power output affected by sunlight, and concentrated output during midday. When PV power generation is high while local load is low, power is transmitted in reverse from the user side to the distribution network side, which can easily raise the voltage at the feeder end and the PV grid connection point, leading to problems such as voltage exceeding limits, inverter disconnection, PV power curtailment, and deterioration of power quality on the user side. Distribution line voltage changes are affected by both active and reactive power, especially in medium and low-voltage distribution networks with high resistance, where active power changes have a significant impact on voltage quality.

[0003] Existing constant reactive power, constant power factor, or single Q(U) control methods have limited voltage regulation capabilities when the inverter's reactive power capacity is insufficient; relying solely on active power limiting may cause unnecessary losses of renewable energy. Therefore, it is necessary to establish a control method that dynamically coordinates active power limiting and reactive power compensation based on voltage status and inverter capacity. Summary of the Invention

[0004] To overcome the above-mentioned shortcomings, this invention proposes a reactive power adaptive voltage regulation method and device for distributed photovoltaic grid connection.

[0005] Firstly, a reactive power adaptive voltage regulation method for distributed photovoltaic grid connection is provided, the method comprising: Obtain the comparison results between the PCC point voltage and the voltage threshold of the photovoltaic grid-connected inverter; Based on the comparison results, the active power command correction value and the reactive power command correction value are determined. The active power command correction value and the reactive power command correction value are used to generate an SPWM drive signal for adjusting the photovoltaic grid-connected inverter, thereby controlling the photovoltaic grid-connected inverter to complete voltage regulation.

[0006] Preferably, determining the active power command correction value and the reactive power command correction value based on the comparison result includes: When the voltage at the PCC point of the photovoltaic grid-connected inverter does not exceed the voltage threshold, the active power command correction value is determined to be the output of the photovoltaic maximum power point, and the reactive power command correction value is generated using the reactive voltage control strategy. When the PCC point voltage of the photovoltaic grid-connected inverter exceeds the voltage threshold, the active power command correction value and reactive power command correction value are determined based on the comparison result between the maximum power point output of the photovoltaic and the upper limit of the output power of the photovoltaic grid-connected inverter.

[0007] Furthermore, the determination of the active power command correction value and reactive power command correction value based on the comparison result between the photovoltaic maximum power point output and the upper limit of the output power of the photovoltaic grid-connected inverter includes: Obtain the upper limit of the output power of the photovoltaic grid-connected inverter. When the upper limit of the output power of the photovoltaic grid-connected inverter exceeds the rated capacity of the photovoltaic grid-connected inverter, set the upper limit of the output power of the photovoltaic grid-connected inverter to equal the rated capacity of the photovoltaic grid-connected inverter. Determine whether the upper limit of the output power of the photovoltaic grid-connected inverter is greater than or equal to the maximum power point output of the photovoltaic system. If so, determine the active power command correction value as the maximum power point output of the photovoltaic system and generate the reactive power command correction value using the reactive voltage control strategy. Otherwise, determine the active power command correction value and the reactive power command correction value based on the absolute difference between the upper limit of the output power of the photovoltaic grid-connected inverter and the maximum power point output of the photovoltaic system.

[0008] Furthermore, the determination of the active power command correction value and reactive power command correction value based on the absolute difference between the upper limit of the output power of the photovoltaic grid-connected inverter and the maximum power point output of the photovoltaic system includes: Determine whether the absolute difference between the upper limit of the output power of the photovoltaic grid-connected inverter and the maximum power point output of the photovoltaic is within the preset range. If so, determine the active power command correction value as the maximum power point output of the photovoltaic, and generate the reactive power command correction value using the reactive voltage control strategy. Otherwise, determine the active power command correction value as the product of the maximum power point output of the photovoltaic and the regulation coefficient, and generate the reactive power command correction value using the reactive voltage control strategy and the power factor angle control strategy.

[0009] Furthermore, the preset range is 0 to (1-x)Pmppt, where x is the adjustment coefficient and Pmppt is the photovoltaic maximum power point output.

[0010] Furthermore, the adjustment coefficient is 0.9.

[0011] Furthermore, the absolute value of the reactive power instruction correction value does not exceed the available reactive power capacity of the photovoltaic grid-connected inverter.

[0012] Furthermore, the available reactive power capacity of the photovoltaic grid-connected inverter is as follows:

[0013] In the above formula, Available reactive power capacity for photovoltaic grid-connected inverters Rated capacity of the photovoltaic grid-connected inverter This represents the current active power output of the photovoltaic grid-connected inverter.

[0014] Preferably, the step of generating an SPWM drive signal for adjusting the photovoltaic grid-connected inverter using the active power command correction value and the reactive power command correction value includes: The active power command correction value and reactive power command correction value are used as active power reference value and reactive power reference value, respectively, and input to the dual-loop decoupling control module of the photovoltaic grid-connected inverter to generate the corresponding SPWM drive signal.

[0015] Furthermore, during the generation of the SPWM drive signal, the maximum change value of the active power reference value and the maximum change value of the reactive power reference value are set. When the difference between the active power reference value and the reactive power reference value and the actual active power reference value and the reactive power reference value of the previous control cycle exceeds the maximum change value, the active power reference value and the reactive power reference value are updated according to the maximum change value.

[0016] Secondly, a reactive power adaptive voltage regulation device for distributed photovoltaic grid connection is provided, the reactive power adaptive voltage regulation device for distributed photovoltaic grid connection comprising: The acquisition module is used to obtain the comparison results between the PCC point voltage and the voltage threshold of the photovoltaic grid-connected inverter; The determination module is used to determine the active power command correction value and the reactive power command correction value based on the comparison result; The adjustment module is used to generate an SPWM drive signal for adjusting the photovoltaic grid-connected inverter using the active power command correction value and the reactive power command correction value, thereby controlling the photovoltaic grid-connected inverter to complete voltage regulation.

[0017] Thirdly, a computer device is provided, comprising: one or more processors; The processor is used to store one or more programs; When the one or more programs are executed by the one or more processors, the reactive power adaptive voltage regulation method for distributed photovoltaic grid connection is implemented.

[0018] Fourthly, a computer-readable storage medium is provided, on which a computer program is stored, wherein when the computer program is executed, the reactive power adaptive voltage regulation method for distributed photovoltaic grid connection is implemented.

[0019] The above-described technical solutions of the present invention have at least one or more of the following beneficial effects: This invention provides a reactive power adaptive voltage regulation method and apparatus for distributed photovoltaic (PV) grid connection, comprising: acquiring a comparison result between the PCC point voltage of the PV grid-connected inverter and a voltage threshold; determining an active power command correction value and a reactive power command correction value based on the comparison result; and generating an SPWM drive signal for regulating the PV grid-connected inverter using the active power command correction value and the reactive power command correction value, thereby controlling the PV grid-connected inverter to complete voltage regulation. The technical solution provided by this invention achieves a unified approach to PV inverter active power output control, residual reactive power capacity utilization, voltage reference adaptive correction, and islanding-assisted identification. Specifically: This invention utilizes the influence of both active and reactive power on the distribution network voltage. When the PCC voltage exceeds the limit, it directly reduces the reverse power flow by limiting active power generation and uses the remaining capacity for reactive power compensation. This allows it to continue to suppress the rise in voltage at the feeder end under conditions where the single reactive power control capability is insufficient, thereby improving the voltage qualification rate of the distribution network.

[0020] In the technical solution provided by this invention, when the expected reduction is small, the power generation is precisely limited according to the upper limit of active power; when the expected reduction exceeds 10% of the maximum available active power, the actual reduction ratio is limited to 10%, and the reactive power compensation then undertakes the subsequent voltage regulation task, avoiding excessive curtailment of solar power in pursuit of voltage control. The reduced energy can also be transferred to high load or emergency periods through energy storage devices.

[0021] This invention calculates the remaining reactive capacity of the inverter based on real-time active power output, so that the reactive power reference value changes dynamically with P and S. It combines voltage PI regulation, voltage reference PI regulation and program limiting mechanism to avoid long-term saturation, frequent oscillation or over-adjustment of reactive power control, and adapts to different access locations, light levels and load conditions.

[0022] This invention does not change the original power distribution network line architecture, does not require additional independent reactive power compensation devices, and does not rely on the frequent operation of on-load tap-changing transformers. It can directly rely on existing photovoltaic grid-connected inverters to complete voltage support, power distribution, and islanding auxiliary detection, thereby reducing the probability of photovoltaic grid disconnection due to voltage exceeding limits and improving the carrying capacity of new energy sources and the level of maintenance safety. Attached Figure Description

[0023] Figure 1 This is a schematic flowchart of the main steps of the reactive power adaptive voltage regulation method for distributed photovoltaic grid connection according to an embodiment of the present invention. Detailed Implementation

[0024] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Example 1 See appendix Figure 1 , Figure 1 This is a schematic flowchart illustrating the main steps of a reactive power adaptive voltage regulation method for distributed photovoltaic grid connection according to an embodiment of the present invention. Figure 1 As shown, the reactive power adaptive voltage regulation method for distributed photovoltaic grid connection in this embodiment of the invention mainly includes the following steps: Step S101: Obtain the comparison result between the PCC point voltage and the voltage threshold of the photovoltaic grid-connected inverter; Step S102: Determine the active power command correction value and the reactive power command correction value based on the comparison result; Step S103: Use the active power command correction value and reactive power command correction value to generate an SPWM drive signal for adjusting the photovoltaic grid-connected inverter, and control the photovoltaic grid-connected inverter to complete voltage regulation.

[0027] In this embodiment, determining the active power command correction value and the reactive power command correction value based on the comparison result includes: When the voltage at the PCC point of the photovoltaic grid-connected inverter does not exceed the voltage threshold, the active power command correction value is determined to be the output of the photovoltaic maximum power point, and the reactive power command correction value is generated using the reactive voltage control strategy. When the PCC point voltage of the photovoltaic grid-connected inverter exceeds the voltage threshold, the active power command correction value and reactive power command correction value are determined based on the comparison result between the maximum power point output of the photovoltaic and the upper limit of the output power of the photovoltaic grid-connected inverter.

[0028] In one implementation, determining the active power command correction value and the reactive power command correction value based on the comparison result between the photovoltaic maximum power point output and the upper limit of the output power of the photovoltaic grid-connected inverter includes: Obtain the upper limit of the output power of the photovoltaic grid-connected inverter. When the upper limit of the output power of the photovoltaic grid-connected inverter exceeds the rated capacity of the photovoltaic grid-connected inverter, set the upper limit of the output power of the photovoltaic grid-connected inverter to equal the rated capacity of the photovoltaic grid-connected inverter. Determine whether the upper limit of the output power of the photovoltaic grid-connected inverter is greater than or equal to the maximum power point output of the photovoltaic system. If so, determine the active power command correction value as the maximum power point output of the photovoltaic system and generate the reactive power command correction value using the reactive voltage control strategy. Otherwise, determine the active power command correction value and the reactive power command correction value based on the absolute difference between the upper limit of the output power of the photovoltaic grid-connected inverter and the maximum power point output of the photovoltaic system.

[0029] In one embodiment, determining the active power command correction value and the reactive power command correction value based on the absolute difference between the upper limit of the output power of the photovoltaic grid-connected inverter and the maximum power point output of the photovoltaic system includes: Determine whether the absolute difference between the upper limit of the output power of the photovoltaic grid-connected inverter and the maximum power point output of the photovoltaic is within the preset range. If so, determine the active power command correction value as the maximum power point output of the photovoltaic, and generate the reactive power command correction value using the reactive voltage control strategy. Otherwise, determine the active power command correction value as the product of the maximum power point output of the photovoltaic and the regulation coefficient, and generate the reactive power command correction value using the reactive voltage control strategy and the power factor angle control strategy.

[0030] In one embodiment, the preset range is 0 to (1-x)Pmppt, where x is an adjustment coefficient and Pmppt is the photovoltaic maximum power point output.

[0031] In one embodiment, the adjustment coefficient is 0.9.

[0032] In one implementation, the absolute value of the reactive power instruction correction value does not exceed the available reactive power capacity of the photovoltaic grid-connected inverter.

[0033] In one embodiment, the reactive power capacity of the photovoltaic grid-connected inverter is as follows:

[0034] In the above formula, Available reactive power capacity for photovoltaic grid-connected inverters Rated capacity of the photovoltaic grid-connected inverter This represents the current active power output of the photovoltaic grid-connected inverter.

[0035] In this embodiment, the step of generating an SPWM drive signal for adjusting the photovoltaic grid-connected inverter using the active power command correction value and the reactive power command correction value includes: The active power command correction value and reactive power command correction value are used as active power reference value and reactive power reference value, respectively, and input to the dual-loop decoupling control module of the photovoltaic grid-connected inverter to generate the corresponding SPWM drive signal.

[0036] In one implementation, during the generation of the SPWM drive signal, a maximum change value for the active power reference value and a maximum change value for the reactive power reference value are set. When the difference between the active power reference value and the reactive power reference value and the actual active power reference value and the reactive power reference value of the previous control cycle exceeds the maximum change value, the active power reference value and the reactive power reference value are updated according to the maximum change value.

[0037] Example 2 Based on the same inventive concept, the present invention also provides a reactive power adaptive voltage regulation device for distributed photovoltaic grid connection, the reactive power adaptive voltage regulation device for distributed photovoltaic grid connection comprising: The acquisition module is used to obtain the comparison results between the PCC point voltage and the voltage threshold of the photovoltaic grid-connected inverter; The determination module is used to determine the active power command correction value and the reactive power command correction value based on the comparison result; The adjustment module is used to generate an SPWM drive signal for adjusting the photovoltaic grid-connected inverter using the active power command correction value and the reactive power command correction value, thereby controlling the photovoltaic grid-connected inverter to complete voltage regulation.

[0038] Preferably, determining the active power command correction value and the reactive power command correction value based on the comparison result includes: When the voltage at the PCC point of the photovoltaic grid-connected inverter does not exceed the voltage threshold, the active power command correction value is determined to be the output of the photovoltaic maximum power point, and the reactive power command correction value is generated using the reactive voltage control strategy. When the PCC point voltage of the photovoltaic grid-connected inverter exceeds the voltage threshold, the active power command correction value and reactive power command correction value are determined based on the comparison result between the maximum power point output of the photovoltaic and the upper limit of the output power of the photovoltaic grid-connected inverter.

[0039] Furthermore, the determination of the active power command correction value and reactive power command correction value based on the comparison result between the photovoltaic maximum power point output and the upper limit of the output power of the photovoltaic grid-connected inverter includes: Obtain the upper limit of the output power of the photovoltaic grid-connected inverter. When the upper limit of the output power of the photovoltaic grid-connected inverter exceeds the rated capacity of the photovoltaic grid-connected inverter, set the upper limit of the output power of the photovoltaic grid-connected inverter to equal the rated capacity of the photovoltaic grid-connected inverter. Determine whether the upper limit of the output power of the photovoltaic grid-connected inverter is greater than or equal to the maximum power point output of the photovoltaic system. If so, determine the active power command correction value as the maximum power point output of the photovoltaic system and generate the reactive power command correction value using the reactive voltage control strategy. Otherwise, determine the active power command correction value and the reactive power command correction value based on the absolute difference between the upper limit of the output power of the photovoltaic grid-connected inverter and the maximum power point output of the photovoltaic system.

[0040] Furthermore, the determination of the active power command correction value and reactive power command correction value based on the absolute difference between the upper limit of the output power of the photovoltaic grid-connected inverter and the maximum power point output of the photovoltaic system includes: Determine whether the absolute difference between the upper limit of the output power of the photovoltaic grid-connected inverter and the maximum power point output of the photovoltaic is within the preset range. If so, determine the active power command correction value as the maximum power point output of the photovoltaic, and generate the reactive power command correction value using the reactive voltage control strategy. Otherwise, determine the active power command correction value as the product of the maximum power point output of the photovoltaic and the regulation coefficient, and generate the reactive power command correction value using the reactive voltage control strategy and the power factor angle control strategy.

[0041] Furthermore, the preset range is 0 to (1-x)Pmppt, where x is the adjustment coefficient and Pmppt is the photovoltaic maximum power point output.

[0042] Furthermore, the adjustment coefficient is 0.9.

[0043] Furthermore, the absolute value of the reactive power instruction correction value does not exceed the available reactive power capacity of the photovoltaic grid-connected inverter.

[0044] Furthermore, the available reactive power capacity of the photovoltaic grid-connected inverter is as follows:

[0045] In the above formula, Available reactive power capacity for photovoltaic grid-connected inverters Rated capacity of the photovoltaic grid-connected inverter This represents the current active power output of the photovoltaic grid-connected inverter.

[0046] Preferably, the step of generating an SPWM drive signal for adjusting the photovoltaic grid-connected inverter using the active power command correction value and the reactive power command correction value includes: The active power command correction value and reactive power command correction value are used as active power reference value and reactive power reference value, respectively, and input to the dual-loop decoupling control module of the photovoltaic grid-connected inverter to generate the corresponding SPWM drive signal.

[0047] Furthermore, during the generation of the SPWM drive signal, the maximum change value of the active power reference value and the maximum change value of the reactive power reference value are set. When the difference between the active power reference value and the reactive power reference value and the actual active power reference value and the reactive power reference value of the previous control cycle exceeds the maximum change value, the active power reference value and the reactive power reference value are updated according to the maximum change value.

[0048] Example 3 Based on the same inventive concept, this invention also provides a computer device, which includes a processor and a memory. The memory stores a computer program, which includes program instructions. The processor executes the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing and control core of the terminal, suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions in the computer storage medium to implement corresponding method flows or corresponding functions, thereby realizing the steps of the reactive power adaptive voltage regulation method for distributed photovoltaic grid connection in the above embodiments.

[0049] Example 4 Based on the same inventive concept, this invention also provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device used to store programs and data. It is understood that the computer-readable storage medium here can include both the built-in storage medium in the computer device and extended storage media supported by the computer device. The computer-readable storage medium provides storage space that stores the terminal's operating system. Furthermore, this storage space also stores one or more instructions suitable for loading and execution by a processor. These instructions can be one or more computer programs (including program code). It should be noted that the computer-readable storage medium here can be high-speed RAM or non-volatile memory, such as at least one disk storage device. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the steps of the reactive power adaptive voltage regulation method for distributed photovoltaic grid connection in the above embodiments.

[0050] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0051] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0052] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0053] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0054] 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 it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A reactive power adaptive voltage regulation method for distributed photovoltaic grid connection, characterized in that, The method includes: Obtain the comparison results of the grid-connected PCC point voltage and the voltage threshold of the photovoltaic grid-connected inverter; Based on the comparison results, the active power command correction value and the reactive power command correction value are determined. The active power command correction value and reactive power command correction value are used to generate a sinusoidal pulse width modulation (SPWM) drive signal for adjusting the photovoltaic grid-connected inverter, thereby controlling the photovoltaic grid-connected inverter to complete voltage regulation.

2. The method as described in claim 1, characterized in that, The process of determining the active power command correction value and the reactive power command correction value based on the comparison result includes: When the voltage at the PCC point of the photovoltaic grid-connected inverter does not exceed the voltage threshold, the active power command correction value is determined to be the output of the photovoltaic maximum power point, and the reactive power command correction value is generated using the reactive voltage control strategy. When the PCC point voltage of the photovoltaic grid-connected inverter exceeds the voltage threshold, the active power command correction value and reactive power command correction value are determined based on the comparison result between the maximum power point output of the photovoltaic and the upper limit of the output power of the photovoltaic grid-connected inverter.

3. The method as described in claim 2, characterized in that, The determination of active power command correction values ​​and reactive power command correction values ​​based on the comparison result between the maximum power point output of photovoltaics and the upper limit of the output power of the photovoltaic grid-connected inverter includes: Obtain the upper limit of the output power of the photovoltaic grid-connected inverter. When the upper limit of the output power of the photovoltaic grid-connected inverter exceeds the rated capacity of the photovoltaic grid-connected inverter, set the upper limit of the output power of the photovoltaic grid-connected inverter to equal the rated capacity of the photovoltaic grid-connected inverter. Determine whether the upper limit of the output power of the photovoltaic grid-connected inverter is greater than or equal to the maximum power point output of the photovoltaic system. If so, determine the active power command correction value as the maximum power point output of the photovoltaic system and generate the reactive power command correction value using the reactive voltage control strategy. Otherwise, determine the active power command correction value and the reactive power command correction value based on the absolute difference between the upper limit of the output power of the photovoltaic grid-connected inverter and the maximum power point output of the photovoltaic system.

4. The method as described in claim 3, characterized in that, The determination of active power command correction values ​​and reactive power command correction values ​​based on the absolute difference between the upper limit of the output power of the photovoltaic grid-connected inverter and the maximum power point output of the photovoltaic system includes: Determine whether the absolute difference between the upper limit of the output power of the photovoltaic grid-connected inverter and the maximum power point output of the photovoltaic is within the preset range. If so, determine the active power command correction value as the maximum power point output of the photovoltaic, and generate the reactive power command correction value using the reactive voltage control strategy. Otherwise, determine the active power command correction value as the product of the maximum power point output of the photovoltaic and the regulation coefficient, and generate the reactive power command correction value using the reactive voltage control strategy and the power factor angle control strategy.

5. The method as described in claim 4, characterized in that, The preset range is 0 to (1-x)Pmppt, where x is the adjustment coefficient and Pmppt is the photovoltaic maximum power point output.

6. The method as described in claim 5, characterized in that, The adjustment coefficient is 0.

9.

7. The method as described in claim 4, characterized in that, The absolute value of the reactive power instruction correction value shall not exceed the available reactive power capacity of the photovoltaic grid-connected inverter.

8. The method as described in claim 7, characterized in that, The available reactive power capacity of the photovoltaic grid-connected inverter is as follows: In the above formula, Available reactive power capacity for photovoltaic grid-connected inverters Rated capacity of the photovoltaic grid-connected inverter This represents the current active power output of the photovoltaic grid-connected inverter.

9. The method as described in claim 1, characterized in that, The step of generating an SPWM drive signal for adjusting the photovoltaic grid-connected inverter using the active power command correction value and the reactive power command correction value includes: The active power command correction value and reactive power command correction value are used as active power reference value and reactive power reference value, respectively, and input to the dual-loop decoupling control module of the photovoltaic grid-connected inverter to generate the corresponding SPWM drive signal.

10. The method as described in claim 9, characterized in that, During the generation of SPWM drive signals, the maximum change values ​​of active power reference value and reactive power reference value are set. When the difference between the active power reference value and the reactive power reference value and the actual active power reference value and reactive power reference value of the previous control cycle exceeds the maximum change value, the active power reference value and reactive power reference value are updated according to the maximum change value.

11. An apparatus based on the reactive power adaptive voltage regulation method for distributed photovoltaic grid connection according to any one of claims 1-10, characterized in that, The device includes: The acquisition module is used to obtain the comparison results between the PCC point voltage and the voltage threshold of the photovoltaic grid-connected inverter; The determination module is used to determine the active power command correction value and the reactive power command correction value based on the comparison result; The adjustment module is used to generate an SPWM drive signal for adjusting the photovoltaic grid-connected inverter using the active power command correction value and the reactive power command correction value, thereby controlling the photovoltaic grid-connected inverter to complete voltage regulation.

12. A computer device, characterized in that, include: One or more processors; The processor is used to execute one or more programs; When the one or more programs are executed by the one or more processors, the reactive power adaptive voltage regulation method for distributed photovoltaic grid connection as described in any one of claims 1 to 10 is implemented.

13. A computer-readable storage medium, characterized in that, It contains a computer program, which, when executed, implements the reactive power adaptive voltage regulation method for distributed photovoltaic grid connection as described in any one of claims 1 to 10.

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