A reactive power and voltage regulation method, device, equipment and storage medium for a photovoltaic and energy storage power station

Abstract

The present application provides a reactive voltage regulation method, device, equipment and storage medium for a photovoltaic energy storage power station. The method includes: detecting in real time the voltage deviation between the voltage measurement value and the voltage target value at the grid connection point of the photovoltaic power station; calculating the reactive power regulation demand according to the voltage deviation; if the voltage deviation is not equal to 0, determining a reactive power regulation strategy according to a preset seven-region diagram; determining the reactive power output of multiple reactive power sources according to the reactive power regulation strategy, where the reactive power sources include photovoltaic inverters, SVG and energy storage converters; and regulating the reactive voltage of the photovoltaic energy storage virtual synchronous power station according to the reactive power output of the multiple reactive power sources. The present application realizes the coordinated control of multiple objectives such as stable grid-connected voltage and maximized dynamic reserve of SVG by reasonably distributing the reactive power regulation demand among various devices.

Description

Technical Field

[0001] This application belongs to the field of reactive power regulation, and particularly relates to a method, device, equipment, and storage medium for reactive power and voltage regulation in a photovoltaic and energy storage power station. Background Technique

[0002] In the context of the increasingly severe global energy crisis and environmental challenges, renewable energy power generation technology is gradually becoming the focus. To efficiently and stably manage these new energy power stations, the voltage control system (AVC system), as the core of the operation of new energy power stations, plays a crucial role. The AVC system precisely regulates various reactive power source devices in the new energy power stations connected to the power grid, such as dynamic reactive power compensation devices (SVG / SVC), inverters, and energy storage converters, to ensure the stable operation of the power grid.

[0003] However, with the rapid development of new energy power station technology, the increasingly powerful functions and significantly improved performance of equipment have also brought new challenges in voltage control. Especially in the face of diverse reactive power regulation devices (such as photovoltaic inverters, energy storage converters, etc.), the complex and variable operating states thereof increase the difficulty of voltage control. Specifically, the reactive power regulation ability of a photovoltaic inverter is directly affected by its active power output, and the reactive power output of an energy storage converter is closely related to its current operating state. These characteristics make the formulation and implementation of voltage control strategies more complex.

[0004] Currently, the main problems faced by the AVC system in practical applications include: first, the diversity and combined complexity of control objects, and the coordinated operation between different devices requires fine planning; second, the coupling relationship between the reactive power output and active power output of a photovoltaic inverter requires the control strategy to have a high degree of flexibility; third, the dynamic change of the reactive power output ability of an energy storage converter places higher requirements on the real-time response ability of the system.

[0005] In view of the inconsistency of control strategies between different AVC systems, it has a significant impact on the coordinated operation of new energy power stations and the power grid voltage. Therefore, optimizing the control strategy of the AVC system and achieving precise coordination between various reactive power source devices are the key to improving the voltage stability of new energy power stations and promoting the efficient operation of the power grid. Summary of the Invention

[0006] The purpose of this application is to overcome the problems existing in the above-mentioned prior art and provide a method, device, equipment, and storage medium for reactive power and voltage regulation in a photovoltaic and energy storage power station.

[0007] This application provides a method for reactive power and voltage regulation in a photovoltaic and energy storage power station, including:

[0008] Real-time detecting the voltage deviation between the voltage measurement value and the voltage target value at the grid connection point of the photovoltaic power station;

[0009] Calculate the reactive power regulation demand based on the voltage deviation;

[0010] If the voltage deviation is not equal to 0, determine the reactive power regulation strategy according to the preset seven - zone diagram;

[0011] Determine the reactive power output of multiple reactive power sources according to the reactive power regulation strategy, where the reactive power sources include photovoltaic inverters, SVG, and energy storage converters;

[0012] Regulate the reactive power and voltage of the photovoltaic - energy - storage virtual synchronous power station according to the reactive power output of multiple reactive power sources.

[0013] Optionally, the reactive power regulation strategy includes:

[0014] In region Z1, no additional control measures are taken;

[0015] In region Z2, enable the photovoltaic inverter and the SVG for reactive power and voltage regulation;

[0016] In region Z3: Enable the photovoltaic inverter and the SVG for reactive power and voltage regulation;

[0017] In region Z4: Put into a group of reactors, and enable the reactors, the photovoltaic inverter, and the SVG for reactive power and voltage regulation;

[0018] In region Z5: Put into a group of capacitors, and enable the capacitors, the photovoltaic inverter, and the SVG for reactive power and voltage regulation;

[0019] In region Z6: Put into a group of reactors, and enable the reactors, the photovoltaic inverter, the SVG, and the energy storage converter for reactive power and voltage regulation;

[0020] In region Z7: Put into a group of capacitors, and enable the capacitors, the photovoltaic inverter, the SVG, and the energy storage converter for reactive power and voltage regulation.

[0021] Optionally, determining the reactive power output of multiple reactive power sources according to the reactive power regulation strategy includes:

[0022] Calculate the reactive power distribution coefficients of the photovoltaic inverter, the SVG, and the energy storage converter:

[0023]

[0024] Calculate the reactive power regulation amounts of the photovoltaic inverter, the SVG, and the energy storage converter as:

[0025]

[0026] Wherein, i represents the numbers of the photovoltaic inverter, the SVG, and the energy storage converter, n is the number of reactive power sources, △Q is the reactive power regulation demand, and P gi is the active power.

[0027] Optionally, it further includes:

[0028] Correct the reactive power regulation amounts of the photovoltaic inverter, the SVG, and the energy storage converter, and the expression is as follows:

[0029]

[0030] If the reactive power of the photovoltaic inverter, the SVG, or the energy storage converter reaches the upper limit or the lower limit, fix it at the boundary;

[0031] Wherein, Q gi_max and Q gi_min are respectively the upper limit and the lower limit of the reactive power of the branch, and Q gi is the reactive power.

[0032] Optionally, regulate the reactive power and voltage of the photovoltaic-storage virtual synchronous power station according to the reactive power outputs of multiple reactive power sources, including:

[0033] If the reactive power output of one reactive power source reaches the maximum reactive power output of the reactive power source, fix the reactive power output of the reactive power source at the maximum reactive power output;

[0034] If the total reactive power output of multiple reactive power sources is greater than the reactive power regulation demand, allocate the surplus of the total reactive power output to the reactive power sources that have not reached the maximum reactive power output.

[0035] Optionally, it further includes:

[0036] If the reactive power regulation demand is equal to 0, release the reactive power output of the reactive power source.

[0037] Optionally, the photovoltaic power station is a centralized photovoltaic power station.

[0038] This application also provides a device for regulating the reactive power and voltage of a photovoltaic-storage power station, including:

[0039] A detection module for detecting the voltage deviation between the measured voltage value and the voltage target value at the grid connection point of the photovoltaic power station in real time;

[0040] A calculation module for calculating the reactive power regulation demand according to the voltage deviation;

[0041] A strategy module for determining a reactive power regulation strategy according to a preset seven-region diagram when the voltage deviation is not equal to 0;

[0042] A distribution module, configured to determine the reactive power outputs of multiple reactive power sources according to the reactive power regulation strategy, where the reactive power sources include a photovoltaic inverter, an SVG, and a battery energy storage converter;

[0043] A regulation module, configured to regulate the reactive power and voltage of a photovoltaic-battery virtual synchronous power station according to the reactive power outputs of the multiple reactive power sources.

[0044] This application also provides a reactive power and voltage regulation device for a photovoltaic-battery power station, including:

[0045] A memory;

[0046] A processor, configured to retrieve a computer-executable program of the above reactive power and voltage regulation method for a photovoltaic-battery power station from the memory and execute: real-time detecting a voltage deviation between a voltage measurement value and a voltage target value at the grid connection point of a photovoltaic power station; calculating a reactive power regulation demand according to the voltage deviation; if the voltage deviation is not equal to 0, determining a reactive power regulation strategy according to a preset seven-region diagram; determining the reactive power outputs of multiple reactive power sources according to the reactive power regulation strategy, where the reactive power sources include a photovoltaic inverter, an SVG, and a battery energy storage converter; and regulating the reactive power and voltage of a photovoltaic-battery virtual synchronous power station according to the reactive power outputs of the multiple reactive power sources.

[0047] This application also provides a storage medium, including a computer-executable program stored therein, where the computer-executable program is configured to be retrieved by a processor and execute the steps of the above reactive power and voltage regulation method for a photovoltaic-battery power station.

[0048] The beneficial effects of this application are:

[0049] This application provides a reactive power and voltage regulation method for a photovoltaic-battery power station, including: real-time detecting a voltage deviation between a voltage measurement value and a voltage target value at the grid connection point of a photovoltaic power station; calculating a reactive power regulation demand according to the voltage deviation; if the voltage deviation is not equal to 0, determining a reactive power regulation strategy according to a preset seven-region diagram; determining the reactive power outputs of multiple reactive power sources according to the reactive power regulation strategy, where the reactive power sources include a photovoltaic inverter, an SVG, and a battery energy storage converter; and regulating the reactive power and voltage of a photovoltaic-battery virtual synchronous power station according to the reactive power outputs of the multiple reactive power sources. By reasonably distributing the reactive power regulation demand among various devices, this application achieves coordinated multi-objectives such as stable grid-connected voltage and maximized dynamic reserve of SVG. Description of the Drawings

[0050] Figure 1 is a schematic diagram of the control principle of the existing nine-region diagram of a substation in this application;

[0051] Figure 2 is a schematic diagram of the reactive power and voltage regulation process of a photovoltaic-battery power station in this application;

[0052] Figure 3 is a schematic diagram of the reactive power and voltage control link in this application;

[0053] Figure 4 It is a schematic diagram for the analysis of the AVC seven - zone map in this application. Specific embodiments

[0054] The following further illustrates the present application in conjunction with the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present application and be able to implement it.

[0055] The automatic voltage control (AVC) optimization calculation module of a photovoltaic power station, the core of which is to adopt a nine - zone coordinated control strategy. This is a highly integrated and intelligent power grid regulation method, aiming to ensure that the voltage and reactive power of the photovoltaic power station operate within the optimal range, thereby improving the stability and economy of the power grid.

[0056] Please refer to Figure 1 As shown, the nine - zone control strategy divides the voltage - reactive power plane into nine regions by setting the upper and lower limits of voltage (such as Umin and Umax) and the upper and lower limits of power factor (such as and ). These nine regions represent different voltage and power factor states. Among them, the B2 region is the ideal state where both voltage and power factor are within the qualified range, and the remaining regions indicate that corresponding control measures need to be taken to restore to the ideal state.

[0057] When the voltage is unqualified: If the voltage exceeds the upper limit (such as entering the A region), priority should be given to reducing the tap position of the on - load tap - changing transformer to reduce the voltage output. If the voltage is lower than the lower limit (such as entering the C region), on the contrary, the tap position of the on - load tap - changing transformer should be raised to increase the voltage.

[0058] When the power factor is unqualified: When the power factor is low (such as from B2 to A2), it indicates that the system needs more reactive power support. At this time, the power factor can be increased by putting into capacitors or adjusting the control strategy of the fan (such as increasing the excitation current). When the power factor is high and the voltage also exceeds the normal range (such as from B2 to C1), first, the voltage needs to be adjusted (as described above), and then it may be necessary to reduce the reactive power compensation equipment (such as capacitors) that has been put into use to avoid over - compensation.

[0059] The output power of a photovoltaic power station is affected by various factors such as light intensity and temperature, and has significant fast - changing characteristics. To address this challenge, the AVC system adopts a hierarchical reactive power - voltage control structure:

[0060] Primary voltage regulation:

[0061] Utilize the fast response ability of the Static Var Generator (SVG) to regulate the voltage of the connected 35kV bus at the millisecond time scale, effectively suppressing the voltage fluctuations caused by the rapid change of photovoltaic power output. The regulation at this level aims to quickly stabilize the voltage level of the local power grid.

[0062] Secondary voltage regulation:

[0063] On the second time scale, the AVC system controls the output of the photovoltaic inverter by calculating and adjusting the voltage set value of the SVG in real time, so as to regulate the voltage of the grid connection point (such as the 220kV bus) to the set value. The regulation at this level is more refined, aiming to achieve the voltage optimization and reactive power balance of the global power grid.

[0064] In the control structure of the above AVC system, precise and efficient coordinated control of multiple reactive power sources is a crucial link. This is because the operating characteristics of the photovoltaic power station, especially the intermittency of its power output, will cause rapid and large fluctuations in the grid voltage. In order to maintain the stability of the power grid and the power quality, these fluctuations must be compensated in a timely and effective manner.

[0065] Among many reactive power sources, the Static Var Generator (SVG) is favored because of its excellent performance. SVG is a reactive power compensation device based on power electronics technology. It can respond and regulate the reactive power of the system within a very short time (millisecond level), thus achieving rapid control of the voltage. This fast response ability is particularly important for coping with the voltage fluctuations caused by the intermittency of photovoltaic power generation, because it can almost instantaneously offset these fluctuations and prevent them from having an adverse impact on the power grid.

[0066] However, despite the excellent performance of SVG, its high price and limited configuration capacity cannot be ignored. The manufacturing cost of SVG is relatively high, which results in the limited configuration capacity of SVG in photovoltaic power stations. Therefore, when using SVG for reactive power compensation, it is necessary to be frugal and ensure that every resource can be utilized most reasonably.

[0067] Please refer to Figure 2 As shown, this application provides a method for regulating reactive power and voltage of a photovoltaic energy storage power station, and its steps include:

[0068] S101. Detect the voltage deviation between the voltage measurement value and the voltage target value of the grid connection point of the photovoltaic power station in real time.

[0069] In the automatic voltage control (AVC) of a photovoltaic power station or other distributed energy systems, to ensure that the bus voltage at the point of interconnection (POI) can be stably maintained near the target value (Uref), the system needs to continuously monitor the actual measured value (UPOI) of the bus voltage at the point of interconnection and calculate the control deviation (ΔU) to guide the regulation of reactive power. In this process, the control logic and control strategies involved are crucial for maintaining grid stability and optimizing system performance.

[0070] The control deviation (ΔU) is obtained by comparing the actual measured value (UPOI) of the bus voltage at the point of interconnection with the target value (Uref), and the specific calculation method is as follows:

[0071]

[0072] Where: Udb is the per-unit value of the voltage control dead zone, usually set to 0.01 p.u. (per-unit value), which is used to avoid frequent adjustment of reactive power equipment during small voltage fluctuations, reducing equipment wear and unnecessary energy consumption. Kp is the proportional regulation coefficient, which is used to directly adjust the reactive power output according to the magnitude of the current deviation to achieve fast response. Ki is the integral regulation coefficient, which is used to eliminate the static error, that is, when there is a deviation in the system for a long time, the integral action gradually accumulates and adjusts the reactive power output until the deviation is zero.

[0073] S102. Calculate the reactive power regulation demand according to the voltage deviation.

[0074] According to the calculated voltage deviation, the system will switch between two control modes:

[0075] As Figure 3 shown, the voltage tracking mode: when ΔQ≠0, it indicates that the voltage at the point of interconnection deviates from the target value, and the system needs to enter the voltage tracking mode. In this mode, the system will adjust the output of the reactive power equipment according to the sign and magnitude of ΔQ to make the voltage at the point of interconnection gradually approach and stabilize at the target value.

[0076] The reactive power replacement mode: when ΔQ = 0, it means that the voltage at the point of interconnection is already near the target value (i.e., within the dead zone range), and at this time the system can switch to the reactive power replacement mode. In this mode, the goal of the system is no longer to directly regulate the voltage, but to optimize the allocation of reactive power resources to maximize the dynamic reactive power reserve. This usually involves the redistribution of reactive power among reactive power sources such as SVG, photovoltaic inverters, and energy storage converters to ensure that the system has sufficient reactive power reserve to respond quickly when the voltage fluctuates greatly.

[0077] S103. If the voltage deviation is not equal to 0, determine the reactive power regulation strategy according to the preset seven-zone diagram.

[0078] The seven - zone diagram control strategy is an optimization method for the automatic voltage control of photovoltaic power plants. Based on the current operating conditions of the photovoltaic power plant, it combines two key parameters, the measured voltage (UPOI) and reactive power (Q), to formulate a more refined and adaptable control strategy. Through comprehensive logic criteria, this strategy divides the voltage - reactive power plane into seven different control regions, each corresponding to different control logics and measures to achieve precise control of equipment such as photovoltaic inverters, static var generators (SVG), and battery energy storage converters (BESS).

[0079] In the seven - zone diagram control strategy, the upper and lower limits of voltage and reactive power (such as Umin, Umax, Qmin, Qmax) and their sensitivity characteristics between them are the basis for dividing the control regions. These limits and characteristics jointly define seven different control regions, each reflecting a specific aspect of the current operating state of the photovoltaic power plant, such as high or low voltage, excess or insufficient reactive power, etc.

[0080] For each control region, corresponding control strategies are formulated. These strategies aim to maintain or restore voltage and reactive power to the desired range by adjusting the reactive power output of photovoltaic inverters, SVG, and battery energy storage converters. For example, in the region where the voltage is low and the reactive power is also low, it may be necessary to increase the reactive power output of both photovoltaic inverters and SVG simultaneously to boost the voltage and supplement reactive power; while in the region where the voltage is normal but the reactive power is excessive, it may be necessary to reduce the reactive power output of SVG or adjust the operating mode of the battery energy storage converter to avoid adverse effects on the power grid caused by excessive reactive power.

[0081] In this application, the system needs to continuously monitor the measured values of voltage and reactive power, and judge which control region the current photovoltaic power plant is operating in according to these values. Once the control region is determined, the system will automatically adjust the control parameters of relevant equipment according to the control strategy corresponding to that region to achieve precise control of voltage and reactive power.

[0082] Based on the power flow sensitivity method, the influence of various regulation means on the voltage and reactive power at the POI point can be further analyzed. The relationships between various regulation means and the voltage UPOI and reactive power at the POI point are as follows:

[0083]

[0084] Among them, Qinv, Qsvg, and Qbess are the reactive power of the photovoltaic inverter, the reactive power of the SVG, and the reactive power compensation of the battery energy storage converter respectively.

[0085] This analysis helps to understand the interaction and effect differences between different regulation means, so as to formulate a more coordinated and optimized control strategy.

[0086] When the voltages of all nodes in the system are close to 1 (i.e., close to the rated voltage), there will be a certain approximate relationship between the sensitivities of various regulation means to the state variables at the POI point, and the expression is as follows:

[0087]

[0088] This helps to simplify the control logic and improve the control efficiency.

[0089] Taking voltage and reactive power as coordinate axes, the plane is divided into seven regions, and the control strategies and main regulation means of each region are marked.

[0090] S104. Determine the reactive power outputs of multiple reactive power sources according to the reactive power regulation strategy, where the reactive power sources include photovoltaic inverters, SVG, and energy storage converters.

[0091] As Figure 4 shown, Umax and Umin are the feasible upper and lower voltage limits respectively. In AVC control, Umax = Uref + Udb / 2, Umax = Uref - Udb / 2, where Uref is the voltage reference value given by the system AVC to the photovoltaic power station, and Udb is the AVC control dead zone of the photovoltaic power station, which is set to 1 kV here. Qmax and Qmin are the current upper and lower limits of reactive power regulation of the photovoltaic power station. Z1 is the feasible region, Z2 and Z3 are the adjustable regions of the photovoltaic inverter, Z4 and Z5 are the adjustable regions of SVG, and Z6 and Z7 are the adjustable regions of the energy storage converter.

[0092] The U-Q feasible region boundary (Umin, Umax, Qmin, Qmax) of the POI of the photovoltaic power station and the control limit boundary divide the entire U-Q into 7 regions, and the expression of the control limit boundary is as follows:

[0093]

[0094] In the formula,

[0095] Region Z1 (normal region): Within this region, the voltage and reactive power of the photovoltaic power station are both within the normal range, and no additional control intervention is required.

[0096] Region Z2 (over-compensation region): When the photovoltaic power station is in this region, it indicates that the voltage is too high and the reactive power may be excessive. The control strategy first reduces the reactive power output of the photovoltaic inverter, and the expression is as follows:

[0097] ΔQ inv = max{Q inv_min -Q inv ,ΔQ}

[0098] where Qinv_min is the lower limit of the reactive power output of the PV inverter

[0099] to try to adjust the voltage and reactive power back to Zone Z1.

[0100] If the adjustment ability of the PV inverter is insufficient to meet the demand, the voltage is further adjusted by the SVG, and the expression is as follows:

[0101]

[0102] where Usvg is the bus voltage at the SVG connection point, kr is the per-unit value of the transformation ratio of the main transformer of the PV power station, and XT is the reactance of the main transformer.

[0103] Meanwhile, if the energy storage system is in the on state, the energy storage converter is preferentially used to replace the reactive power output of the SVG to retain the dynamic reactive power support ability of the SVG.

[0104] Zone Z3 (under-compensation zone): Contrary to Z2, this zone indicates that the voltage is low and the reactive power may be insufficient. Similarly, the reactive power output of the PV inverter is increased first, and the expression is as follows:

[0105] ΔQ inv =min{Q inv_max -Q inv ,ΔQ}

[0106] where Qinv_max is the upper limit of the reactive power output of the PV inverter

[0107] to try to boost the voltage.

[0108] If further adjustment is required, the voltage control target value is set by the SVG, and the expression is as follows:

[0109]

[0110] where Usvg is the bus voltage at the SVG connection point, kr is the per-unit value of the transformation ratio of the main transformer of the PV power station, and XT is the reactance of the main transformer.

[0111] And the energy storage converter is also considered to replace part of the reactive power output of the SVG.

[0112] Zones Z4 and Z5 (increasing reactive power capacity): These two zones change the upper and lower limits of the reactive power of the PV power station (Q'min, Q'max) by putting into reactors (Z4) or capacitors (Z5) to expand the adjustable zone. The control strategy is similar to that of Z2 or Z3, but the increase in reactive power capacity is considered, making the adjustment strategy more flexible.

[0113] Regions Z6 and Z7 (enabling the reactive power capability of the energy storage converter): Similar to Z4 and Z5, these two regions also expand the control strategy by changing the reactive power limit and enabling the reactive power regulation capability of the energy storage converter. In Z6, if reactive power needs to be reduced, the energy storage converter works in coordination with the PV inverter; in Z7, if reactive power needs to be increased, the energy storage converter, SVG, and PV inverter jointly regulate.

[0114] S105. Regulate the reactive power and voltage of the PV-ESS virtual synchronous power station according to the reactive power output of multiple said reactive power sources.

[0115] In a PV-ESS virtual synchronous power station, branches (such as PV inverters and their connected PV arrays) and reactive power sources (such as the PV inverter itself) are usually closely connected. Specifically, each branch (such as a PV inverter) is a potential reactive power source because it can adjust its reactive power output according to the control strategy.

[0116] After determining the total reactive power regulation amount of each reactive power source in the PV power station, taking the branch as the control object, determine the reactive power regulation target of each branch according to the equal power factor principle. The specific steps are as follows:

[0117] S201. Equivalent the branch to a PV inverter and an energy storage converter, and denote the active power and reactive power of the branch as Pgi and Qgi respectively. There are n allocated branches in total.

[0118] S202. Calculate the reactive power distribution coefficient of each branch according to the following formula:

[0119]

[0120] S203. The reactive power regulation amount of each branch is:

[0121] ΔQ gi =α i ΔQ

[0122] S204. Check the reactive power regulation ability of each branch, and correct the reactive power regulation amount according to the following formula:

[0123]

[0124] In the above formula, if the reactive power of a branch reaches the upper limit or lower limit, fix it at the boundary.

[0125] Among them, Qgi_max and Qgi_min are the upper limit and lower limit of the reactive power of the branch respectively.

[0126] S205. Suppose there are m branches with reactive power boundaries in total, then the total reactive power regulation margin is:

[0127]

[0128] If the total reactive power regulation margin is greater than the threshold and the number of distributable branches is greater than 0, then proceed to step S201 for the next round of distribution; otherwise, the distribution ends.

[0129] The final reactive power regulation amount of each branch is the superposition of multiple rounds of distribution.

[0130] The present application also provides a reactive power and voltage regulation device for a photovoltaic and energy storage power station, including:

[0131] A detection module for detecting in real time the voltage deviation between the voltage measurement value and the voltage target value at the grid connection point of the photovoltaic power station;

[0132] A calculation module for calculating the reactive power regulation demand according to the voltage deviation;

[0133] A strategy module for determining a reactive power regulation strategy according to a preset seven-region diagram when the voltage deviation is not equal to 0;

[0134] A distribution module for determining the reactive power output of multiple reactive power sources according to the reactive power regulation strategy, where the reactive power sources include photovoltaic inverters, SVG, and energy storage converters;

[0135] A regulation module for regulating the reactive power and voltage of the photovoltaic and energy storage virtual synchronous power station according to the reactive power output of multiple reactive power sources.

[0136] The present application also provides a reactive power and voltage regulation device for a photovoltaic and energy storage power station, including:

[0137] A memory;

[0138] A processor for retrieving a computer-executable program of the above reactive power and voltage regulation method for a photovoltaic and energy storage power station from the memory and executing: detecting in real time the voltage deviation between the voltage measurement value and the voltage target value at the grid connection point of the photovoltaic power station; calculating the reactive power regulation demand according to the voltage deviation; determining a reactive power regulation strategy according to a preset seven-region diagram when the voltage deviation is not equal to 0; determining the reactive power output of multiple reactive power sources according to the reactive power regulation strategy, where the reactive power sources include photovoltaic inverters, SVG, and energy storage converters; regulating the reactive power and voltage of the photovoltaic and energy storage virtual synchronous power station according to the reactive power output of multiple reactive power sources.

[0139] The present application also provides a storage medium including a computer-executable program stored therein, and the computer-executable program is used to be retrieved by a processor to execute the steps of the above reactive power and voltage regulation method for a photovoltaic and energy storage power station.

[0140] The above-described embodiments and / or implementation manners are merely used to illustrate the preferred embodiments and / or implementation manners for implementing the technology of the present invention, and do not impose any formal restrictions on the implementation manners of the technology of the present invention. Any person skilled in the art, without departing from the scope of the technical means disclosed in the content of the present invention, may make some changes or modifications to other equivalent embodiments, but should still be regarded as the same technology or embodiment as the present invention in essence.

[0141] Specific examples are used in this article to elaborate on the principles and implementation manners of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application. The above is only the preferred implementation manner of the present application. It should be noted that due to the limited nature of written expression and the objectively infinite specific structures, for those of ordinary skill in the art, without departing from the principles of the present application, several improvements, refinements or changes may be made, and the above technical features may also be combined in an appropriate manner; the improvements, refinements, changes or combinations, or the direct application of the inventive concept and technical solution to other occasions without improvement, should all be regarded as within the protection scope of the present application.

Claims

1. A method for controlling reactive voltage of a photovoltaic power station, characterized in that: include: Real-time detection of voltage deviation between the voltage measurement value and the voltage target value at the photovoltaic power station grid connection point; Calculating reactive power regulation demand according to the voltage deviation; If the voltage deviation is not equal to 0, the reactive power regulation strategy is determined according to the preset seven-zone diagram, including: zone Z1, no additional control measures are taken; zone Z2, the photovoltaic inverter and the static VAR generator are enabled for reactive voltage regulation; zone Z3: the photovoltaic inverter and the static VAR generator are enabled for reactive voltage regulation; zone Z4: a group of reactors are put into use, the reactor, the photovoltaic inverter and the static VAR generator are enabled for reactive voltage regulation; zone Z5: a group of capacitors are put into use, the capacitor, the photovoltaic inverter and the static VAR generator are enabled for reactive voltage regulation; zone Z6: a group of reactors are put into use, the reactor, the photovoltaic inverter, the static VAR generator and the energy storage converter are enabled for reactive voltage regulation; zone Z7: a group of capacitors are put into use, the capacitor, the photovoltaic inverter, the static VAR generator and the energy storage converter are enabled for reactive voltage regulation; According to the reactive power regulation strategy, the reactive power output of multiple reactive power sources is determined, including: calculating reactive power distribution coefficients of the photovoltaic inverter, the static reactive power generator and the energy storage converter: The reactive power regulation amount of the photovoltaic inverter, the static VAR generator and the energy storage converter is calculated as: Wherein, i represents the serial number of the photovoltaic inverter, the static VAR generator and the energy storage converter, n is the number of reactive sources, ΔQ is the reactive regulation demand, P gi is active power, the reactive power source includes a photovoltaic inverter, a static VAR generator and an energy storage converter; The reactive power regulation amount of the photovoltaic inverter, the static VAR generator and the energy storage converter is corrected, and the expression is as follows: If the reactive power of the photovoltaic inverter, the static VAR generator or the energy storage converter reaches the upper or lower limit, it is fixed to the boundary; wherein, Q gi_max , Q gi_min are the upper and lower limits of the reactive power of the branch, Q gi is the reactive power; The reactive voltage of the photovoltaic storage virtual synchronous power station is regulated according to the reactive output of the multiple reactive sources, including: if the reactive output of one of the reactive sources reaches the maximum reactive output of the reactive source, the reactive output of the reactive source is fixed to the maximum reactive output; if the total reactive output of the multiple reactive sources is greater than the reactive regulation demand, the surplus of the total reactive output is allocated to the reactive sources that have not reached the maximum reactive output.

2. According to claim 1, a reactive voltage control method for a photovoltaic power station is characterized in that: Also includes: If the reactive power regulation demand is equal to 0, the reactive power output of the reactive power source is released.

3. According to claim 1, a reactive voltage control method for a photovoltaic power station is characterized in that: The photovoltaic power station is a centralized photovoltaic power station.

4. A reactive voltage control device for a photovoltaic power station, characterized in that: include: A detection module, used to detect in real time the voltage deviation between the voltage measurement value and the voltage target value of the photovoltaic power station grid connection point; A calculation module, used for calculating reactive power regulation demand according to the voltage deviation; A strategy module is used to determine the reactive power regulation strategy according to a preset seven-zone diagram if the voltage deviation is not equal to 0, including: zone Z1, no additional control measures are taken; zone Z2, photovoltaic inverter and static VAR generator are enabled for reactive voltage regulation; zone Z3: the photovoltaic inverter and the static VAR generator are enabled for reactive voltage regulation; zone Z4: a group of reactors are put into use, the reactor, the photovoltaic inverter and the static VAR generator are enabled for reactive voltage regulation; zone Z5: a group of capacitors are put into use, the capacitor, the photovoltaic inverter and the static VAR generator are enabled for reactive voltage regulation; zone Z6: a group of reactors are put into use, the reactor, the photovoltaic inverter, the static VAR generator and the energy storage converter are enabled for reactive voltage regulation; zone Z7: a group of capacitors are put into use, the capacitor, the photovoltaic inverter, the static VAR generator and the energy storage converter are enabled for reactive voltage regulation; The distribution module is used to determine the reactive output of multiple reactive sources according to the reactive regulation strategy, including: calculating the reactive distribution coefficients of the photovoltaic inverter, the static reactive generator and the energy storage converter: The reactive power regulation amount of the photovoltaic inverter, the static VAR generator and the energy storage converter is calculated as: Wherein, i represents the serial number of the photovoltaic inverter, the static VAR generator and the energy storage converter, n is the number of reactive sources, ΔQ is the reactive regulation demand, P gi is the active power, and the reactive power source includes a photovoltaic inverter, a static VAR generator and an energy storage converter; the reactive power adjustment amount of the photovoltaic inverter, the static VAR generator and the energy storage converter is corrected, and the expression is as follows: If the reactive power of the photovoltaic inverter, the static VAR generator or the energy storage converter reaches the upper or lower limit, it is fixed to the boundary; wherein, Q gi_max , Q gi_min are the upper and lower limits of the reactive power of the branch, Q gi is the reactive power; A control module is used to control the reactive voltage of the photovoltaic storage virtual synchronous power station according to the reactive output of the multiple reactive sources, including: if the reactive output of one of the reactive sources reaches the maximum reactive output of the reactive source, then the reactive output of the reactive source is fixed to the maximum reactive output; if the total reactive output of the multiple reactive sources is greater than the reactive regulation demand, then the surplus of the total reactive output is allocated to the reactive sources that have not reached the maximum reactive output.

5. A reactive voltage control device for a photovoltaic power station, characterized in that: include: Memory; A processor, configured to retrieve from the memory a computer executable program of the reactive voltage control method for a photovoltaic power station according to any one of claims 1 to 3, and execute: real-time detection of a voltage deviation between a voltage measurement value at a photovoltaic power station grid connection point and a voltage target value; Calculating reactive power regulation demand according to the voltage deviation; If the voltage deviation is not equal to 0, the reactive power regulation strategy is determined according to the preset seven-zone diagram, including: Zone Z1, no additional control measures are taken; Zone Z2, the photovoltaic inverter and the static VAR generator are enabled for reactive voltage regulation; Zone Z3: the photovoltaic inverter and the static VAR generator are enabled for reactive voltage regulation; Zone Z4: a group of reactors are put into use, the reactors, the photovoltaic inverter and the static VAR generator are enabled for reactive voltage regulation; Zone Z5: a group of capacitors are put into use, the capacitors, the photovoltaic inverter and the static VAR generator are enabled for reactive voltage regulation. The static VAR generator performs reactive voltage regulation; Area Z6: puts in a group of reactors, enables the reactors, the photovoltaic inverter, the static VAR generator and the energy storage converter to perform reactive voltage regulation; Area Z7: puts in a group of capacitors, enables the capacitors, the photovoltaic inverter, the static VAR generator and the energy storage converter to perform reactive voltage regulation; according to the reactive regulation strategy, determines the reactive output of multiple reactive sources, including: calculating the reactive distribution coefficient of the photovoltaic inverter, the static VAR generator and the energy storage converter: The reactive power regulation amount of the photovoltaic inverter, the static VAR generator and the energy storage converter is calculated as: Wherein, i represents the serial number of the photovoltaic inverter, the static VAR generator and the energy storage converter, n is the number of reactive sources, ΔQ is the reactive regulation demand, P gi is the active power, and the reactive power source includes a photovoltaic inverter, a static VAR generator and an energy storage converter; the reactive power adjustment amount of the photovoltaic inverter, the static VAR generator and the energy storage converter is corrected, and the expression is as follows: If the reactive power of the photovoltaic inverter, the static VAR generator or the energy storage converter reaches the upper or lower limit, it is fixed to the boundary; wherein, Q gi_max , Q gi_min are the upper and lower limits of the reactive power of the branch, Q gi Reactive power; the reactive voltage of the photovoltaic storage virtual synchronous power station is regulated according to the reactive output of multiple reactive sources, including: if the reactive output of one reactive source reaches the maximum reactive output of the reactive source, the reactive output of the reactive source is fixed to the maximum reactive output; if the total reactive output of multiple reactive sources is greater than the reactive regulation demand, the surplus of the total reactive output is allocated to the reactive sources that have not reached the maximum reactive output.

6. A storage medium, characterized in that: It includes storing a computer executable program, which is used to be called by a processor to execute the steps of the reactive voltage control method of a photovoltaic power station according to any one of claims 1 to 3.

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