Photovoltaic power station aggregation control method, controller, readable storage medium and photovoltaic power station

Abstract

The invention relates to a photovoltaic power station aggregation control method, a controller, a readable storage medium and a photovoltaic power station. According to the method, a target scene matched with a preset typical scene can be determined through the current time and the current sunlight intensity, and based on the initial value of the capacity ratio of a grid-following type inverter and the initial value of the capacity ratio of a grid-constructing type inverter of the target scene and the bus voltage of a photovoltaic power station, the grid-constructing type inverter of the target scene can be determined. And correspondingly adjusting the capacity ratio of the grid-following type inverter and the capacity ratio of the grid-constructing type inverter until the bus voltage is equal to the preset voltage corresponding to the target scene. According to the photovoltaic power station aggregation control method, the stability of the power distribution network can be improved through the joint input of the network-following type inverter and the network-constructing type inverter.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic power station control technology, and in particular to a photovoltaic power station aggregation control method, a controller, a readable storage medium and a photovoltaic power station. Background Art

[0002] With the proposal of carbon peak and carbon neutrality, people have an increasing demand for clean and environmentally friendly energy. Therefore, in the power system, more and more distributed photovoltaic power stations are connected to the distribution network. However, the access of photovoltaic power stations will change the operating characteristics of the distribution network.

[0003] In traditional solutions, inverters in photovoltaic power stations often use inverters with a grid-following architecture. However, when a disturbance occurs in the distribution network, the grid-following inverter does not provide sufficient support for dynamic power and voltage, resulting in unstable voltage in the distribution network. Summary of the invention

[0004] Based on this, it is necessary to provide a photovoltaic power station aggregation control method, controller, readable storage medium and photovoltaic power station that can improve the voltage stability of the distribution network in response to the above technical problems.

[0005] In a first aspect, the present application provides a photovoltaic power station aggregation control method, wherein the photovoltaic power station includes a plurality of grid-following inverters and at least one grid-building inverter connected in parallel, and the method includes:

[0006] Get the current time and current sunshine intensity;

[0007] Determine a target scene that matches the current time and the current sunlight intensity from a plurality of preset typical scenes;

[0008] According to the target scenario and the mapping relationship between multiple preset typical scenarios and inverter capacity, determine the initial value of the capacity proportion of the grid-following inverter and the initial value of the capacity proportion of the grid-building inverter under the target scenario;

[0009] Obtain the bus voltage of the photovoltaic power station;

[0010] When the bus voltage is not equal to the preset voltage corresponding to the target scenario, the initial value of the capacity proportion of the grid-following inverter and the initial value of the capacity proportion of the grid-building inverter are adjusted until the bus voltage is equal to the preset voltage corresponding to the target scenario.

[0011] In one of the embodiments, the initial value of the capacity proportion of the grid-type inverter is positively correlated with the size of the preset voltage, and the initial value of the capacity proportion of the grid-type inverter is negatively correlated with the size of the preset voltage.

[0012] In one of the embodiments, when the bus voltage is not equal to the preset voltage corresponding to the target scenario, the step of adjusting the initial value of the capacity proportion of the grid-following inverter and the initial value of the capacity proportion of the grid-building inverter includes:

[0013] When the bus voltage is lower than the preset voltage, the capacity proportion of the grid-connected inverter is increased based on the initial value of the capacity proportion;

[0014] When the bus voltage is greater than the preset voltage, the capacity proportion of the grid-connected inverter is adjusted up or down based on the initial value of the capacity proportion.

[0015] In one embodiment, the step of adjusting the capacity ratio of the grid-connected inverter includes:

[0016] Based on the difference between the bus voltage and the preset voltage, as well as the current value of the capacity proportion of each grid-following inverter and the current value of the capacity proportion of each grid-forming inverter, the type conversion of the grid-following inverter and the grid-forming inverter is performed.

[0017] In one embodiment, the step of converting the type of the grid-following inverter and the grid-building inverter includes:

[0018] Based on the difference between the bus voltage and the preset voltage, the target capacity ratio of the grid-connected inverter is determined;

[0019] If the sum of the capacity proportions of the target grid-following inverters among multiple grid-following inverters is equal to the target capacity proportion, the grid-forming inverters that have been put into use are first converted into grid-following inverters, and then the target grid-following inverters are converted into grid-forming inverters.

[0020] In one embodiment, when the bus voltage is less than a preset voltage, the step of increasing the capacity share based on the initial value of the capacity share of the grid-type inverter includes:

[0021] When the bus voltage is less than the preset voltage, and the absolute value of the difference between the bus voltage and the preset voltage is greater than or equal to the preset hysteresis threshold, the capacity proportion of the grid-connected inverter is increased based on the initial value of the capacity proportion;

[0022] When the bus voltage is greater than the preset voltage, the steps of adjusting the capacity proportion of the grid-type inverter up or down based on the initial value of the capacity proportion include:

[0023] When the bus voltage is greater than the preset voltage, and the absolute value of the difference between the bus voltage and the preset voltage is greater than or equal to the preset hysteresis threshold, the capacity share of the grid-connected inverter is adjusted up or down based on the initial value of the capacity share.

[0024] In one embodiment, it also includes:

[0025] According to the target scenario, the initial control parameters of the grid-connected inverter that has been put into use are determined; wherein the initial control parameters include active proportional control parameters, active integral control parameters, reactive proportional control parameters and reactive integral control parameters;

[0026] When the current sunshine intensity is greater than the light threshold, the active proportional control parameter and the active integral control parameter are increased;

[0027] When the current sunshine intensity is less than or equal to the light threshold, the reactive power proportional control parameter and the reactive power integral control parameter are increased.

[0028] In the second aspect, the present application also provides a controller including a memory and a processor, the memory storing a computer program, characterized in that the controller is respectively connected to a grid-following inverter and a grid-building inverter, and the processor implements any step of the above-mentioned photovoltaic power station aggregation control method when executing the computer program.

[0029] In a third aspect, the present application further provides a computer-readable storage medium on which a computer program is stored, and when the computer program is executed by a processor, any step of the above-mentioned photovoltaic power station aggregation control method is implemented.

[0030] In a fifth aspect, the present application further provides a photovoltaic power station, the photovoltaic power station comprising:

[0031] multiple photovoltaic panels to convert solar energy into electricity;

[0032] A plurality of grid-following inverters, wherein the input ends of the plurality of grid-following inverters are respectively connected to the output ends of the plurality of photovoltaic panels, and the output ends of the grid-following inverters are used to connect to the grid bus;

[0033] At least one grid-forming inverter connected in parallel with the grid-following inverter, the input end of the grid-forming inverter correspondingly connected to the output end of the photovoltaic panel, and the output end of the grid-forming inverter used to connect to the grid bus;

[0034] As the controller mentioned above, the controller is connected to the grid-following inverter and the grid-building inverter respectively.

[0035] The above photovoltaic power station aggregation control method, controller, readable storage medium and photovoltaic power station can determine the target scene that matches the preset typical scene through the current time and the current sunshine intensity, and adjust the capacity proportion of the grid-following inverter and the capacity proportion of the grid-building inverter according to the initial value of the capacity proportion of the grid-following inverter and the initial value of the capacity proportion of the grid-building inverter of the target scene and the bus voltage of the photovoltaic power station until the bus voltage is equal to the preset voltage corresponding to the target scene. The photovoltaic power station aggregation control method can improve the stability of the distribution network by jointly investing the grid-following inverter and the grid-building inverter. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the drawings required for use in the embodiments of the present application or related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 This is an application environment diagram of a photovoltaic power station aggregation control method in an embodiment;

[0038] Figure 2 It is a schematic diagram of a process of a photovoltaic power station aggregation control method in one embodiment;

[0039] Figure 3 A curve diagram showing the relationship between the capacity ratio of the grid-type inverter and the voltage per unit value of the grid bus in one embodiment;

[0040] Figure 4 A schematic diagram of a process for determining initial control parameters in a photovoltaic power station aggregation control method in one embodiment;

[0041] Figure 5 is a structural block diagram of a photovoltaic power station aggregation control device in one embodiment;

[0042] Figure 6 FIG. 4 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0044] The photovoltaic power station aggregation control method provided in the embodiment of the present application can be applied to Figure 1 In the application environment shown. Among them, multiple grid-type inverters 102 and at least one grid-forming inverter 104 are connected in parallel with each other through a transformer, and each grid-type inverter and each grid-forming inverter are connected to a photovoltaic panel 106 to form a power generation module in a photovoltaic power station. The controller 108 is respectively connected to each grid-type inverter and each grid-forming inverter to adjust the capacity proportion of the grid-type inverter and the capacity proportion of the grid-forming inverter in the light-emitting module according to the current time and the current sunshine intensity, so that the bus voltage of the current photovoltaic power station is equal to the preset voltage of the preset typical scene corresponding to the current time and the current sunshine intensity.

[0045] In an exemplary embodiment, Figure 2As shown, a photovoltaic power station aggregation control method is provided, and the method is applied to Figure 1 The controller in is used as an example to illustrate, including:

[0046] S202, obtaining the current time and the current sunshine intensity.

[0047] S204: Determine a target scene that matches the current time and the current sunlight intensity from a plurality of preset typical scenes.

[0048] The preset typical scenes are scenes divided according to time and sunshine intensity. Specifically, the preset typical scenes include sunny morning, cloudy morning, rainy morning, sunny noon, cloudy noon, rainy noon, sunny evening, cloudy evening, and rainy evening. Of course, the above weather conditions are only examples, and the sunshine intensity of the preset typical scenes can be finely divided according to the numerical value of the sunshine intensity; correspondingly, the above time periods are only examples, and the specific time of the preset typical scenes can be 30 minutes, 1 hour, 1.5 hours, etc. as the time span to obtain multiple time periods.

[0049] According to the preset typical scene, the target scene with the same time and sunshine intensity can be determined. Further, when there are fewer samples of the preset typical scene, the scene with the smallest deviation between the current time and the current sunshine intensity and the time and sunshine intensity of the preset typical scene can be determined as the target scene.

[0050] S206, determining an initial value of the capacity proportion of the grid-following inverter and an initial value of the capacity proportion of the grid-forming inverter in the target scenario according to the target scenario and a mapping relationship between a plurality of preset typical scenarios and the inverter capacity.

[0051] The power generation of a photovoltaic power station is different under different light intensities, and the light intensity is also different at different times. Therefore, the corresponding power generation under the preset typical scenario can be determined according to time and power generation, that is, the capacity proportion of each grid-following inverter and the capacity proportion of the grid-connected inverter in the photovoltaic power station can be determined.

[0052] The mapping relationship between the preset typical scene and the inverter capacity can be determined according to the sunshine intensity at the current moment, and the current sunshine intensity can be maximized, so that the busbar of the photovoltaic power station can output the maximum voltage that can be achieved at the current moment. Therefore, for different times and different sunshine intensities, the capacity proportion of the grid-following inverter and the capacity proportion of the grid-building inverter corresponding to the preset typical scene can be determined one by one, and the capacity proportion of the grid-following inverter and the capacity proportion of the grid-building inverter are used as the initial values ​​of the capacity proportion of the grid-following inverter and the initial values ​​of the capacity proportion of the grid-building inverter of the target scene.

[0053] Furthermore, when all inverters are grid-following inverters, the corresponding power generation under each typical application scenario can be determined, and then the optimal solution for the capacity ratio of the grid-forming inverter under each typical application scenario can be determined through experiments. In this way, the initial value of the capacity ratio of the grid-following inverter and the initial value of the capacity ratio of the grid-forming inverter corresponding to each typical application scenario can be determined.

[0054] S208, obtaining the bus voltage of the photovoltaic power station.

[0055] S210, when the bus voltage is not equal to the preset voltage corresponding to the target scenario, adjust the initial value of the capacity proportion of the grid-following inverter and the initial value of the capacity proportion of the grid-forming inverter until the bus voltage is equal to the preset voltage corresponding to the target scenario.

[0056] The capacity proportions of the grid-following inverter and the capacity proportions of the grid-building inverter are adjusted based on the initial values ​​of the capacity proportions of the grid-following inverter and the initial values ​​of the capacity proportions of the grid-building inverter, so that the current capacity proportions of the grid-following inverter and the capacity proportions of the grid-building inverter can enable the bus voltage of the photovoltaic power station to reach the preset voltage corresponding to the target scenario, thereby maximizing the use of solar energy for power generation and reducing the consumption of other non-renewable energy.

[0057] The use of grid-following inverters and grid-building inverters together can reduce the harmonic oscillation of the distribution network and improve stability. Furthermore, when only one grid-building inverter and multiple grid-following inverters are used, the circulating current caused by the parallel connection of multiple grid-building inverters can be reduced while taking into account the stability of the distribution network.

[0058] Furthermore, although the control methods of the grid-following inverter and the grid-building inverter are different, the topological structures of the two are the same. Therefore, the conversion between the grid-following inverter and the grid-building inverter can be quickly realized by using the corresponding software functions. Furthermore, in the photovoltaic power station, each inverter can be pre-set with a fixed capacity ratio, and the capacity ratio of the grid-following inverter and the capacity ratio of the grid-building inverter can be adjusted by the conversion between the grid-following inverter and the grid-building inverter.

[0059] In the above photovoltaic power station aggregation control method, the target scene matching the preset typical scene can be determined by the current time and the current sunshine intensity, and based on the initial value of the capacity proportion of the grid-following inverter and the initial value of the capacity proportion of the grid-building inverter of the target scene and the bus voltage of the photovoltaic power station, the capacity proportion of the grid-following inverter and the capacity proportion of the grid-building inverter are adjusted accordingly until the bus voltage is equal to the preset voltage corresponding to the target scene. The photovoltaic power station aggregation control method can improve the stability of the distribution network by jointly investing the grid-following inverter and the grid-building inverter.

[0060] In an exemplary embodiment, the initial value of the capacity ratio of the grid-type inverter is positively correlated with the size of the preset voltage, and the initial value of the capacity ratio of the grid-type inverter is negatively correlated with the size of the preset voltage.

[0061] Under the same light intensity, the larger the initial value of the capacity proportion of the grid-connected inverter, the higher the bus voltage of the photovoltaic power station. Correspondingly, the smaller the initial value of the capacity proportion of the grid-following inverter, the higher the bus voltage of the photovoltaic power station.

[0062] In order to take into account the performance and power generation of each module device in the photovoltaic power station, under different light intensities, the voltage per unit value of the photovoltaic power station bus voltage is stably running around 1.0 as the preset voltage value corresponding to the voltage value.

[0063] Furthermore, corresponding modules may be provided in the photovoltaic power station or corresponding settings may be made for each inverter to ensure that after each inverter transmits the voltage to the transformer connected thereto for transformation, no voltage difference will occur, and the voltage per unit value of the bus voltage of the photovoltaic power station can still stably operate near 1.0 and perform reliable output.

[0064] In an exemplary embodiment, when the bus voltage is not equal to the preset voltage corresponding to the target scenario, adjusting the initial value of the capacity proportion of the grid-following inverter and the initial value of the capacity proportion of the grid-building inverter includes:

[0065] When the bus voltage is lower than the preset voltage, the capacity proportion of the grid-connected inverter is adjusted upward based on the initial value of the capacity proportion.

[0066] When the bus voltage is greater than the preset voltage, the capacity proportion of the grid-connected inverter is adjusted up or down based on the initial value of the capacity proportion.

[0067] When the photovoltaic power station cannot obtain the preset voltage corresponding to the target scenario based on the initial value of the capacity share of the grid-following inverter and the initial value of the capacity share of the grid-building inverter corresponding to the target scenario, the capacity share can be adjusted based on the initial value of the capacity share of the grid-building inverter to obtain the preset voltage corresponding to the target scenario.

[0068] In an exemplary embodiment, the step of adjusting the capacity ratio of the grid-connected inverter includes:

[0069] Based on the difference between the bus voltage and the preset voltage, as well as the current value of the capacity proportion of each grid-following inverter and the current value of the capacity proportion of each grid-forming inverter, the type conversion of the grid-following inverter and the grid-forming inverter is performed.

[0070] According to the difference between the bus voltage and the preset voltage, it can be determined whether the current bus voltage is greater than or less than the preset voltage. When the bus voltage is greater than the preset voltage, it is determined that the inverter type needs to be converted in the direction of reducing the capacity proportion of the grid-forming inverter and increasing the capacity proportion of the grid-following inverter. When the bus voltage is less than the preset voltage, it is determined that the inverter type needs to be converted in the direction of increasing the capacity proportion of the grid-forming inverter and reducing the capacity proportion of the grid-following inverter.

[0071] For example, the case where the capacity ratio of each inverter is the same is used as an example: if there are 5 inverters with a capacity ratio of 20%, including two grid-forming inverters and three grid-following inverters, when the bus voltage is less than the preset voltage, any of the grid-following inverters can be converted into a grid-forming inverter, thereby increasing the capacity ratio of the grid-forming inverter; when the bus voltage is greater than the preset voltage, any of the grid-forming inverters can be converted into a grid-following inverter, thereby reducing the capacity ratio of the grid-forming inverter. Of course, the number of the above inverters is only for example. The smaller the capacity ratio of each inverter, the finer the regulation of the bus voltage of the photovoltaic power station.

[0072] Exemplarily, the case where the capacity proportions of each inverter are not the same is used as an example: if there are a total of 4 inverters with capacity proportions of 10%, 20%, 30%, and 40% respectively, and the inverter with a capacity proportion of 20% is a grid-forming inverter, and the rest are grid-following inverters, when the bus voltage is less than the preset voltage, the grid-following inverter with a capacity proportion of 30% or 40% can be converted into a grid-forming inverter, and the grid-forming inverter with a capacity proportion of 20% can be converted into a grid-following inverter, or, only the grid-following inverter with a capacity proportion of 10% can be converted into a grid-forming inverter, thereby increasing the capacity proportion of the grid-forming inverter; when the bus voltage is greater than the preset voltage, the grid-following inverter with a capacity proportion of 10% can be converted into a grid-forming inverter, and the grid-forming inverter with a capacity proportion of 20% can be converted into a grid-following inverter, thereby reducing the capacity proportion of the grid-forming inverter. Of course, the capacity ratio and quantity of the above inverters are only for illustration and do not specifically limit the specific settings of each inverter.

[0073] In an exemplary embodiment, the steps of converting the type of the grid-following inverter and the grid-building inverter include:

[0074] Based on the difference between the bus voltage and the preset voltage, the target capacity ratio of the grid-connected inverter is determined.

[0075] If the sum of the capacity proportions of the target grid-following inverters among multiple grid-following inverters is equal to the target capacity proportion, the grid-forming inverters that have been put into use are first converted into grid-following inverters, and then the target grid-following inverters are converted into grid-forming inverters.

[0076] When the bus voltage is lower than the preset voltage, if it is determined that the target capacity of the required grid-forming inverter accounts for 30%, and the capacity of the current grid-forming inverter accounts for only 10%, the current grid-forming inverter can be converted into a grid-following inverter, and the grid-following inverter with a capacity share of 30% can be converted into a grid-forming inverter. Such a conversion can ensure that there is at most one grid-forming inverter, thereby avoiding the circulation phenomenon caused by the grid-forming inverter and improving the stability and reliability of the distribution network.

[0077] Correspondingly, when the bus voltage is greater than the preset voltage, the grid-forming inverter that has been put into operation can be converted into a grid-following inverter first, and then a target grid-following inverter with a capacity share equal to the target capacity share can be converted into a grid-forming inverter, which will not be repeated here.

[0078] Of course, when it is necessary to convert multiple grid-following inverters into grid-forming inverters, the grid-forming inverters that have been put into use can be converted into grid-following inverters first, and then the corresponding multiple target grid-following inverters can be converted into grid-forming inverters.

[0079] Furthermore, when converting the inverter type, priority may be given to ensuring that there is at most one grid-type inverter to reduce circulating current. When multiple grid-type inverters are used, the internal impedance of the photovoltaic power station may also be increased to reduce the impact of circulating current.

[0080] In an exemplary embodiment, Figure 3 As shown, when the bus voltage is less than the preset voltage, the steps of increasing the capacity proportion based on the initial value of the capacity proportion of the grid-type inverter include:

[0081] When the bus voltage is less than the preset voltage and the absolute value of the difference between the bus voltage and the preset voltage is greater than or equal to the preset hysteresis threshold, the capacity share of the grid-connected inverter is increased based on the initial value of the capacity share.

[0082] When the bus voltage is greater than the preset voltage, the steps of adjusting the capacity proportion of the grid-type inverter up or down based on the initial value of the capacity proportion include:

[0083] When the bus voltage is greater than the preset voltage, and the absolute value of the difference between the bus voltage and the preset voltage is greater than or equal to the preset hysteresis threshold, the capacity share of the grid-connected inverter is adjusted up or down based on the initial value of the capacity share.

[0084] The setting of the preset hysteresis threshold can ensure that when the bus voltage is not equal to the preset voltage, the inverter type is not immediately converted, but the original configuration of each inverter is maintained to continue to maintain the operation of the distribution network, so as to reduce the conversion of the inverter and increase the life of each inverter.

[0085] Furthermore, the setting of the preset hysteresis threshold can make each inverter in a certain state when the bus voltage is at any voltage value. Figure 3 As shown, if the preset hysteresis threshold is 0.02, when the voltage per unit value of the bus voltage drops to 0.95, each inverter is still allowed to retain its original operating state, and when the voltage per unit value of the bus voltage drops to 0.93, the capacity share of the grid-forming inverter is increased according to the above strategy. Correspondingly, when the voltage per unit value of the bus voltage drops to 0.95, each inverter is still allowed to retain its original operating state, and when the voltage per unit value of the bus voltage drops to 0.97, the capacity share of the grid-forming inverter is reduced according to the above strategy.

[0086] In an exemplary embodiment, the method further includes:

[0087] According to the target scenario, the initial control parameters of the grid-connected inverter that has been put into use are determined; wherein the initial control parameters include active proportional control parameters, active integral control parameters, reactive proportional control parameters and reactive integral control parameters.

[0088] When the current sunshine intensity is greater than the light threshold, the active power proportion control parameter and the active power integral control parameter are increased.

[0089] When the current sunshine intensity is less than or equal to the light threshold, the reactive power proportional control parameter and the reactive power integral control parameter are increased.

[0090] After determining the capacity proportion of the grid-following inverter and the capacity proportion of the grid-building inverter, the voltage support capability of each inverter can be improved by adjusting the initial control parameters.

[0091] like Figure 4 As shown, specifically, the active power ratio control parameter (K P ), active integral control parameters (K I ), reactive power proportional control parameters (Q P ) and reactive integral control parameter (Q I), and perform a global search through the telescopic transformation operator in a preset typical scenario until the updated active proportional control parameter, active integral control parameter, reactive proportional control parameter, and reactive integral control parameter make the voltage per unit value of the bus voltage stable near 1, that is, the difference ε between the actual voltage per unit value and 1 is less than the preset difference ε0, and the updated active proportional control parameter, active integral control parameter, reactive proportional control parameter, and reactive integral control parameter are determined as the initial quantity. Therefore, the corresponding initial control parameters can be determined according to the target scenario.

[0092] Based on the initial control parameters and the current light intensity, local search is performed through rotation, translation and axial transformation operators until the updated active proportional control parameters, active integral control parameters, reactive proportional control parameters and reactive integral control parameters make the voltage per unit value of the bus voltage stable near 1, that is, the difference ε between the actual voltage per unit value and 1 is less than the preset difference ε0, and then each inverter is controlled with the updated active proportional control parameters, active integral control parameters, reactive proportional control parameters and reactive integral control parameters to obtain a stable and reliable bus voltage.

[0093] Furthermore, in the process of determining the active proportional control parameters, active integral control parameters, reactive proportional control parameters and reactive integral control parameters according to the current sunshine intensity and light threshold, weight allocation can be performed based on the order of stability of the distribution network, speed of solution and accuracy of solution, and the greedy criterion can be used to reduce the offset of the bus voltage so as to iteratively update the optimal active proportional control parameters, active integral control parameters, reactive proportional control parameters and reactive integral control parameters.

[0094] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0095] Based on the same inventive concept, the embodiment of the present application also provides a photovoltaic power station aggregation control device for implementing the photovoltaic power station aggregation control method involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in one or more photovoltaic power station aggregation control device embodiments provided below can refer to the limitations of the photovoltaic power station aggregation control method above, and will not be repeated here.

[0096] In an exemplary embodiment, Figure 5 As shown, a photovoltaic power station aggregation control device 500 is provided, the photovoltaic power station includes a plurality of grid-following inverters and at least one grid-forming inverter connected in parallel, and the photovoltaic power station aggregation control device 500 includes: a first acquisition module 502, a matching module 504, an initial value determination module 506, a second acquisition module 508 and an adjustment module 510.

[0097] Wherein: the first acquisition module 502 is used to obtain the current time and the current sunshine intensity.

[0098] The matching module 504 is used to determine a target scene that matches the current time and the current sunlight intensity from a plurality of preset typical scenes.

[0099] The initial value determination module 506 is used to determine the initial value of the capacity proportion of the grid-following inverter and the initial value of the capacity proportion of the grid-forming inverter under the target scenario according to the target scenario and the mapping relationship between multiple preset typical scenarios and inverter capacities.

[0100] The second acquisition module 508 is used to acquire the bus voltage of the photovoltaic power station.

[0101] The adjustment module 510 is used to adjust the initial value of the capacity proportion of the grid-following inverter and the initial value of the capacity proportion of the grid-forming inverter when the bus voltage is not equal to the preset voltage corresponding to the target scenario, until the bus voltage is equal to the preset voltage corresponding to the target scenario.

[0102] In an exemplary embodiment, in the above-mentioned photovoltaic power station aggregation control device 500, the initial value of the capacity proportion of the grid-type inverter is positively correlated with the size of the preset voltage, and the initial value of the capacity proportion of the grid-type inverter is negatively correlated with the size of the preset voltage.

[0103] In an exemplary embodiment, the adjustment module 510 includes: a first adjustment module and a second adjustment module.

[0104] The first adjustment module is used to increase the capacity share of the grid-type inverter based on an initial value of the capacity share when the bus voltage is less than a preset voltage.

[0105] The second adjustment module is used to adjust the capacity proportion of the grid-type inverter up or down based on the initial value of the capacity proportion when the bus voltage is greater than a preset voltage.

[0106] In an exemplary embodiment, the first adjustment module and the second adjustment module include: a type conversion module.

[0107] The type conversion module is used to convert the types of grid-following inverters and grid-forming inverters based on the difference between the bus voltage and the preset voltage, as well as the current value of the capacity share of each grid-following inverter and the current value of the capacity share of each grid-forming inverter.

[0108] In an exemplary embodiment, the type conversion module includes: a target capacity ratio determination module and an input sequence control module.

[0109] Among them, the target capacity ratio determination module is used to determine the target capacity ratio of the grid-connected inverter based on the difference between the bus voltage and the preset voltage.

[0110] The input sequence control module is used to convert the grid-forming inverters that have been put into operation into grid-forming inverters, and then convert the target grid-forming inverters into grid-forming inverters if the sum of the capacity proportions of the target grid-forming inverters among multiple grid-forming inverters is equal to the target capacity proportion.

[0111] In an exemplary embodiment, the first adjustment module includes: a first hysteresis adjustment module.

[0112] The first hysteresis adjustment module is used to increase the capacity share of the grid-connected inverter based on the initial value of the capacity share when the bus voltage is less than a preset voltage and the absolute value of the difference between the bus voltage and the preset voltage is greater than or equal to a preset hysteresis threshold.

[0113] The second adjustment module includes: a second hysteresis adjustment module.

[0114] The second hysteresis adjustment module is used to adjust the capacity share of the grid-type inverter up or down based on the initial value of the capacity share when the bus voltage is greater than the preset voltage and the absolute value of the difference between the bus voltage and the preset voltage is greater than or equal to the preset hysteresis threshold.

[0115] In an exemplary embodiment, the photovoltaic power station aggregation control device 500 further includes: an initial control parameter determination module, an active power increase module and a reactive power increase module.

[0116] Among them, the initial control parameter determination module is used to determine the initial control parameters of the grid-connected inverter that has been put into use according to the target scenario; among them, the initial control parameters include active proportional control parameters, active integral control parameters, reactive proportional control parameters and reactive integral control parameters.

[0117] The active power increasing module is used to increase the active power proportional control parameter and the active power integral control parameter when the current sunshine intensity is greater than the sunshine threshold.

[0118] The reactive power increasing module is used to increase the reactive power proportional control parameter and the reactive power integral control parameter when the current sunshine intensity is less than or equal to the sunshine threshold.

[0119] Each module in the above photovoltaic power station aggregation control device can be implemented in whole or in part by software, hardware, or a combination thereof. Each module can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute operations corresponding to each module.

[0120] In an exemplary embodiment, a computer device is provided. The computer device may be a server, and its internal structure diagram may be as shown in FIG. Figure 6 As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. Among them, the processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store preset typical scenes and mapping relationship data between preset typical scenes and various dimensional parameters. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a photovoltaic power station aggregation control method is implemented.

[0121] Those skilled in the art will understand that Figure 6 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0122] In an exemplary embodiment, a controller is provided, including a memory and a processor, the memory stores a computer program, the controller is connected to a grid-following inverter and a grid-building inverter, respectively, and the processor implements any step of the above-mentioned photovoltaic power station aggregation control method when executing the computer program.

[0123] In an exemplary embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, any step of the above-mentioned photovoltaic power station aggregation control method is implemented.

[0124] In an exemplary embodiment, a photovoltaic power station includes: a plurality of photovoltaic panels, a plurality of grid-connected inverters, at least one grid-connected inverter connected in parallel with the grid-connected inverters, and a controller.

[0125] Multiple photovoltaic panels are used to convert solar energy into electricity.

[0126] The input ends of the multiple grid-following inverters are respectively connected to the output ends of the multiple photovoltaic panels, and the output ends of the grid-following inverters are used to connect to the grid bus.

[0127] The input end of the grid-forming inverter corresponds to the output end of the photovoltaic panel, and the output end of the grid-forming inverter is used to connect to the grid bus.

[0128] The controller is connected to the grid-following inverter and the grid-building inverter respectively, and is used to implement any step of the above-mentioned photovoltaic power station aggregation control method.

[0129] A photovoltaic power station equipped with the above photovoltaic power station aggregation control method can realize automatic control of inverter conversion according to the current time and current sunshine intensity, thereby ensuring the power generation efficiency of the photovoltaic power station.

[0130] In an exemplary embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, any step of the above-mentioned photovoltaic power station aggregation control method is implemented.

[0131] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, any step of the above-mentioned photovoltaic power station aggregation control method is implemented.

[0132] In one embodiment, a computer program product is provided, including a computer program, which implements any step of the above-mentioned photovoltaic power station aggregation control method when executed by a processor.

[0133] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to this.

[0134] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0135] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A photovoltaic power station aggregation control method, characterized in that: The photovoltaic power station includes a plurality of grid-following inverters and at least one grid-building inverter connected in parallel with each other, and the method includes: Get the current time and current sunshine intensity; Determine a target scene matching the current time and the current sunshine intensity from a plurality of preset typical scenes; According to the target scenario and a mapping relationship between a plurality of preset typical scenarios and inverter capacities, determining an initial value of the capacity proportion of the grid-following inverter and an initial value of the capacity proportion of the grid-building inverter under the target scenario; Obtain the bus voltage of the photovoltaic power station; When the bus voltage is not equal to the preset voltage corresponding to the target scenario, adjust the initial value of the capacity proportion of the grid-following inverter and the initial value of the capacity proportion of the grid-forming inverter until the bus voltage is equal to the preset voltage corresponding to the target scenario.

2. The method according to claim 1, characterized in that The initial value of the capacity proportion of the grid-forming inverter is positively correlated with the size of the preset voltage, and the initial value of the capacity proportion of the grid-following inverter is negatively correlated with the size of the preset voltage.

3. The method according to claim 1, characterized in that When the bus voltage is not equal to the preset voltage corresponding to the target scenario, adjusting the initial value of the capacity proportion of the grid-following inverter and the initial value of the capacity proportion of the grid-building inverter includes: When the bus voltage is less than the preset voltage, the capacity proportion of the grid-type inverter is increased based on the initial value of the capacity proportion; When the bus voltage is greater than the preset voltage, the capacity proportion of the grid-type inverter is adjusted up or down based on an initial value of the capacity proportion.

4. The method according to claim 3, characterized in that The step of adjusting the capacity ratio of the grid-connected inverter comprises: Based on the difference between the bus voltage and the preset voltage, as well as the current value of the capacity proportion of each of the grid-following inverters and the current value of the capacity proportion of each grid-forming inverter, the type conversion of the grid-following inverter and the grid-forming inverter is performed.

5. The method according to claim 4, characterized in that The type conversion between the grid-following inverter and the grid-building inverter includes: Determining a target capacity ratio of the grid-connected inverter based on a difference between the bus voltage and the preset voltage; If the sum of the capacity proportions of the target grid-following inverter among the multiple grid-following inverters is equal to the target capacity proportion, the grid-forming inverters that have been put into use are first converted into grid-following inverters, and then the target grid-following inverters are converted into grid-forming inverters.

6. The method according to claim 3, characterized in that When the bus voltage is less than the preset voltage, increasing the capacity proportion of the grid-type inverter based on the initial value of the capacity proportion, comprises: When the bus voltage is less than the preset voltage, and the absolute value of the difference between the bus voltage and the preset voltage is greater than or equal to a preset hysteresis threshold, the capacity proportion of the grid-type inverter is increased based on the initial value of the capacity proportion; When the bus voltage is greater than the preset voltage, adjusting the capacity proportion of the grid-type inverter up or down based on the initial value of the capacity proportion, comprises: When the bus voltage is greater than the preset voltage, and the absolute value of the difference between the bus voltage and the preset voltage is greater than or equal to the preset hysteresis threshold, the capacity share of the grid-type inverter is adjusted up or down based on the initial value of the capacity share.

7. The method according to claim 1, characterized in that Also includes: According to the target scenario, determining the initial control parameters of the grid-connected inverter that has been put into use; wherein the initial control parameters include active proportional control parameters, active integral control parameters, reactive proportional control parameters and reactive integral control parameters; When the current sunshine intensity is greater than the light threshold, increasing the active power proportional control parameter and the active power integral control parameter; When the current sunshine intensity is less than or equal to the light threshold, the reactive proportional control parameter and the reactive integral control parameter are increased.

8. A controller comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: The controller is connected to the grid-following inverter and the grid-forming inverter respectively, and the processor implements the steps of the method described in any one of claims 1 to 7 when executing the computer program.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A photovoltaic power station, characterized in that: The photovoltaic power station comprises: multiple photovoltaic panels to convert solar energy into electricity; A plurality of grid-following inverters, wherein the input ends of the plurality of grid-following inverters are respectively connected to the output ends of the plurality of photovoltaic panels, and the output ends of the grid-following inverters are used to connect to the grid bus; At least one grid-forming inverter connected in parallel with the grid-following inverter, the input end of the grid-forming inverter correspondingly connected to the output end of the photovoltaic panel, and the output end of the grid-forming inverter used to connect to the grid bus; The controller as claimed in claim 8, wherein the controller is connected to the grid-following inverter and the grid-building inverter respectively.

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