Photovoltaic system operation method and device, photovoltaic system and computer equipment

Abstract

The invention relates to a photovoltaic system operation method and device, a photovoltaic system, computer equipment, a storage medium and a computer program product, when a photovoltaic inverter of the photovoltaic system is in a power transmission state, if it is judged that the photovoltaic system meets a three-phase imbalance adjusting condition, three-phase current of a power grid side can be obtained, and the three-phase imbalance adjusting condition can be obtained; and inversion three-phase current during power transmission of the photovoltaic inverter can be obtained. And then the current operation state parameters of the photovoltaic inverter are further combined to analyze and determine the working mode of the photovoltaic inverter. And finally, under the condition that the photovoltaic inverter is in the busy hour working mode, phase current compensation is carried out on the photovoltaic inverter by combining a preset margin parameter of the photovoltaic inverter and the acquired three-phase current of the power grid side and the inversion three-phase current, so that the three-phase unbalance degree of the photovoltaic system is adjusted. By means of the scheme, under the condition that stable power transmission operation of the photovoltaic inverter is maintained, three-phase unbalance degree adjustment of the photovoltaic system is achieved through the photovoltaic inverter.

Description

Technical Field

[0001] The present application relates to the field of new energy technology, and in particular to a photovoltaic system operation method, device, photovoltaic system, computer equipment, storage medium and computer program product. Background Art

[0002] With the development of new energy technologies, photovoltaic power generation has gradually been widely used due to its stable and reliable operation, simple operation and maintenance, low maintenance cost, and long service life. The three-phase imbalance in the photovoltaic system is the main indicator for evaluating the quality of power. In application scenarios such as rural power grids and industrial parks, due to the use of distributed photovoltaic storage systems, the access of high-power single-phase loads, and the asynchronous power consumption of users, the photovoltaic system will have three-phase imbalance, which will have adverse effects on the power grid and power-consuming equipment.

[0003] How to adjust the three-phase imbalance of the photovoltaic system through the photovoltaic inverter when the photovoltaic inverter is in the power transmission mode is a problem that needs to be solved urgently. Summary of the invention

[0004] Based on this, it is necessary to provide a photovoltaic system operation method, device, photovoltaic system, computer equipment, storage medium and computer program product to achieve three-phase unbalanced regulation of the photovoltaic system through the photovoltaic inverter when the photovoltaic inverter is in power transmission mode.

[0005] The present application provides a photovoltaic system operation method, comprising: when the photovoltaic system meets the three-phase unbalance adjustment condition, obtaining the grid-side three-phase current of the photovoltaic system and the inverter three-phase current of the photovoltaic inverter in the photovoltaic system; determining the photovoltaic inverter operation mode according to the current operation state parameters of the photovoltaic inverter; when the photovoltaic inverter is in the busy working mode, performing phase current compensation on the photovoltaic inverter according to the grid-side three-phase current, the inverter three-phase current, and the preset margin parameters of the photovoltaic inverter, so as to adjust the three-phase imbalance of the photovoltaic system.

[0006] In the above scheme, when the photovoltaic inverter of the photovoltaic system is in the power transmission state, that is, the direct current generated by the photovoltaic components of the photovoltaic system is converted into alternating current and transmitted to the alternating current grid to supply power to the electrical equipment, if it is judged that the photovoltaic system meets the three-phase unbalance adjustment conditions, not only the three-phase current on the grid side can be obtained, but also the inverter three-phase current when the photovoltaic inverter is transmitting power. Then, the current operating state parameters of the photovoltaic inverter are further combined to analyze and determine the working mode of the photovoltaic inverter. Finally, when the photovoltaic inverter is in the busy working mode, the phase current compensation of the photovoltaic inverter is performed in combination with the preset margin parameters of the photovoltaic inverter, and the obtained three-phase current on the grid side and the inverter three-phase current, so as to adjust the three-phase imbalance of the photovoltaic system. Through this scheme, when the photovoltaic inverter is transmitting power, the phase current compensation of the photovoltaic inverter can be performed in combination with the preset margin parameters of the photovoltaic inverter and the three-phase current on the grid side and the inverter three-phase current. Thereby, the three-phase imbalance adjustment of the photovoltaic system is realized through the photovoltaic inverter while maintaining the stable power transmission operation of the photovoltaic inverter.

[0007] In some embodiments, the phase current compensation of the photovoltaic inverter is performed according to the grid-side three-phase current, the inverter three-phase current, and the preset margin parameters of the photovoltaic inverter, including: determining the current regulation mode required for the photovoltaic inverter according to the grid-side three-phase current, the inverter three-phase current, and the preset margin parameters of the photovoltaic inverter; when the required current regulation mode is the current increase margin regulation mode, compensating for the minimum phase current in the inverter three-phase current; when the required current regulation mode is the current reduction margin regulation mode, compensating for the maximum phase current in the inverter three-phase current.

[0008] The above scheme can be combined with the actual situation of the photovoltaic inverter to compensate for the minimum phase current or the maximum phase current of the photovoltaic inverter, thereby reducing the three-phase imbalance and having high current compensation control reliability.

[0009] In some embodiments, the preset margin parameters include a preset current boost threshold and a preset maximum allowable current; determining the current regulation mode required for the photovoltaic inverter based on the grid-side three-phase current, the inverter three-phase current, and the preset margin parameters of the photovoltaic inverter includes: obtaining the current sum of the minimum phase current in the inverter three-phase current and the preset current boost threshold; when the minimum phase current in the grid-side three-phase current is greater than the current sum and less than the preset maximum allowable current, determining that the required current regulation mode is the current boost margin regulation mode.

[0010] The above scheme can combine the preset current boost threshold, the preset maximum allowable current, the minimum phase current of the three-phase current on the grid side and the minimum phase current of the inverter three-phase current to determine whether the photovoltaic inverter is in the current boost margin adjustment mode, and has a high accuracy in determining the current boost margin adjustment mode.

[0011] In some embodiments, the preset margin parameters include a preset current reduction threshold and a preset minimum allowable current; determining the current regulation mode required for the photovoltaic inverter based on the grid-side three-phase current, the inverter three-phase current, and the preset margin parameters of the photovoltaic inverter includes: obtaining the current difference between the maximum phase current in the inverter three-phase current and the preset current reduction threshold; when the preset minimum allowable current is greater than the maximum phase current in the grid-side three-phase current and less than the current difference, determining that the required current regulation mode is the current reduction margin regulation mode.

[0012] The above scheme can combine the preset current reduction threshold, the preset minimum allowable current, the maximum phase current of the three-phase current on the grid side and the maximum phase current of the inverter three-phase current to determine whether the photovoltaic inverter is in the current reduction margin adjustment mode, and has a high accuracy in determining the current reduction margin adjustment mode.

[0013] In some embodiments, when the photovoltaic inverter is in a busy working mode, it also includes: when it is determined that the three-phase unbalance adjustment capacity of the photovoltaic inverter is exceeded based on the three-phase current on the grid side, the inverter three-phase current, and the preset margin parameters of the photovoltaic inverter, controlling the three-phase unbalance adjustment device of the photovoltaic system to adjust the three-phase imbalance of the photovoltaic system.

[0014] In the above scheme, when the photovoltaic inverter is in the busy working mode, if the three-phase current on the grid side, the inverter three-phase current, and the preset margin parameters of the photovoltaic inverter are combined, it is judged that the three-phase imbalance at this time exceeds the three-phase imbalance adjustment capability of the photovoltaic inverter. By turning on the three-phase imbalance adjustment device to perform three-phase imbalance adjustment, the reliability of the three-phase imbalance adjustment is improved.

[0015] In some embodiments, when the photovoltaic inverter is in a busy working mode, it also includes: predicting the future required phase sequence of the photovoltaic inverter based on the historical accumulated power generation and historical phase sequence of each phase of the photovoltaic inverter; and controlling the photovoltaic inverter to adjust the phase sequence according to the future required phase sequence.

[0016] The above scheme, when the photovoltaic inverter is in the busy working mode, can further predict the future required phase sequence based on the historical cumulative power generation and historical phase sequence of each phase in the photovoltaic inverter. The photovoltaic inverter will operate with the future required phase sequence at future moments, which can reduce the possibility of the photovoltaic inverter continuing to operate with the same phase sequence, alleviate the loss of the photovoltaic inverter to a certain extent, and improve the operating efficiency of the photovoltaic inverter.

[0017] In some embodiments, after determining the operating mode of the photovoltaic inverter according to the current operating status parameters of the photovoltaic inverter, it also includes: when the photovoltaic inverter is in an idle working mode, performing phase current compensation on the grid side of the photovoltaic system to adjust the three-phase imbalance of the photovoltaic system.

[0018] The above scheme fully puts the photovoltaic inverter into three-phase unbalanced regulation when the photovoltaic inverter is in the idle working mode, without considering the inverter three-phase current and preset margin parameters of the photovoltaic inverter, thereby improving the three-phase unbalanced regulation capability of the photovoltaic inverter.

[0019] In some embodiments, the phase current compensation on the grid side of the photovoltaic system includes: determining the current compensation mode required on the grid side of the photovoltaic system based on the three-phase current on the grid side; when the required current compensation mode is upward compensation, adjusting the minimum phase current in the inverter three-phase current to compensate for the minimum phase current on the grid side; when the required current compensation mode is downward compensation, adjusting the maximum phase current in the inverter three-phase current to compensate for the minimum large phase current on the grid side.

[0020] The above scheme can be combined with the actual situation of the photovoltaic inverter to compensate for the minimum phase current or maximum phase current of the photovoltaic inverter, thereby changing the corresponding phase current in the three-phase current on the grid side, realizing three-phase unbalanced regulation, and has high current compensation control reliability.

[0021] In some embodiments, determining the current compensation mode required for the photovoltaic inverter based on the three-phase current on the grid side includes: obtaining the average value of each phase current in the three-phase current on the grid side; determining a first difference between the maximum phase current of the three-phase current on the grid side and the average value, and a second difference between the average value and the minimum phase current of the three-phase current on the grid side; when the first difference is greater than the second difference, determining that the current compensation mode required for the photovoltaic inverter is upward compensation; when the first difference is less than or equal to the second difference, determining that the current compensation mode required for the photovoltaic inverter is downward compensation.

[0022] The above scheme first obtains the average value of each phase current in the three-phase current on the grid side, and then determines the current compensation mode required by the photovoltaic inverter based on the relationship between the difference between the maximum phase current and the average value, and the difference between the average value and the minimum phase current in the three-phase current on the grid side. It has a high accuracy in determining the current compensation mode.

[0023] In some embodiments, when the photovoltaic inverter is in an idle working mode, it also includes: obtaining the cumulative power generation of each phase of the photovoltaic inverter; selecting the phase with the smallest cumulative power generation as the adjustment phase to change the phase sequence of the photovoltaic inverter.

[0024] In the above scheme, when the photovoltaic inverter is in the idle working mode, the phase with the smallest cumulative power generation can be selected as the adjustment phase to adjust the phase sequence according to the cumulative power generation of each phase in the photovoltaic inverter, so as to balance the three-phase loss of the photovoltaic inverter.

[0025] In some embodiments, the photovoltaic system satisfies the three-phase unbalance adjustment condition, including: determining the three-phase unbalance degree of the photovoltaic system according to the three-phase electrical parameters on the grid side of the photovoltaic system; and determining that the photovoltaic system satisfies the three-phase unbalance adjustment condition when the three-phase unbalance degree is greater than a preset threshold.

[0026] The above scheme determines whether the photovoltaic system meets the three-phase imbalance adjustment conditions through the three-phase imbalance degree determined by the grid-side three-phase electrical parameters of the photovoltaic inverter and the preset threshold, and has high judgment efficiency and judgment accuracy.

[0027] A photovoltaic system operation device comprises: a phase current acquisition module, which is used to acquire the grid-side three-phase current of the photovoltaic system and the inverter three-phase current of the photovoltaic inverter in the photovoltaic system when the photovoltaic system meets the three-phase unbalance adjustment condition; a working mode determination module, which is used to determine the working mode of the photovoltaic inverter according to the current operating state parameters of the photovoltaic inverter; and an unbalance adjustment module, which is used to perform phase current compensation on the photovoltaic inverter according to the grid-side three-phase current, the inverter three-phase current, and the preset margin parameters of the photovoltaic inverter when the photovoltaic inverter is in a busy working mode, so as to adjust the three-phase unbalance of the photovoltaic system.

[0028] A photovoltaic system comprises a photovoltaic module, a photovoltaic inverter, an AC power grid and a controller, wherein the photovoltaic inverter is arranged between the photovoltaic module and the AC power grid, the photovoltaic inverter is connected to the controller, and the controller is used to execute the steps of the photovoltaic system operation method.

[0029] A computer device comprises a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the photovoltaic system operation method when executing the computer program.

[0030] A computer-readable storage medium stores a computer program, which implements the steps of the photovoltaic system operation method when executed by a processor.

[0031] A computer program product comprises a computer program, which implements the steps of the photovoltaic system operation method when executed by a processor. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0033] Figure 1 This is a schematic diagram of the photovoltaic system structure in some embodiments of the present application;

[0034] Figure 2 This is a schematic diagram of the photovoltaic system operation method in some embodiments of the present application;

[0035] Figure 3 This is a schematic diagram of the current compensation process in the busy working mode in some embodiments of the present application;

[0036] Figure 4 This is a schematic diagram of a current regulation mode determination process in some embodiments of the present application;

[0037] Figure 5 A schematic diagram of a current regulation mode determination process in some other embodiments of the present application;

[0038] Figure 6 This is a schematic flow chart of a photovoltaic system operation method in some other embodiments of the present application;

[0039] Figure 7 This is a schematic diagram of the current compensation process in the idle working mode in some embodiments of the present application;

[0040] Figure 8 This is a schematic diagram of a current compensation mode determination process in some embodiments of the present application;

[0041] Fig. 9 This is a schematic diagram of the structure of a photovoltaic system operating device in some embodiments of the present application;

[0042] Fig.10 This is a schematic diagram of the structure of a photovoltaic system operating device in some other embodiments of the present application;

[0043] Fig.11 This is a schematic diagram of the structure of a photovoltaic system operating device in some other embodiments of the present application;

[0044] Fig.12 This is a schematic diagram of the internal structure of a computer device in some embodiments of the present application. DETAILED DESCRIPTION

[0045] The following embodiments of the technical solution of the present application will be described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0047] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0048] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0049] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0050] At present, from the perspective of market development, new energy is gradually replacing traditional fossil energy and occupying an important position in the energy supply field. Among various new energy sources, photovoltaics are widely used due to their stable and reliable operation, simple operation and maintenance, low maintenance cost, and long service life. Photovoltaic power generation is generally combined with AC power grid or energy storage system for grid connection. After the photovoltaic components convert light energy into DC power, they can be directly transmitted to the energy storage system for storage, or they can be converted through photovoltaic inverters and transmitted to the AC power grid to be consumed by electrical equipment in the AC power grid.

[0051] However, in application scenarios such as rural power grids and industrial parks, due to the use of distributed photovoltaic storage systems, the access of high-power single-phase loads, and the asynchronous power consumption of users, the photovoltaic system will inevitably have three-phase imbalance (three-phase current imbalance or three-phase voltage imbalance).

[0052] In order to alleviate the three-phase imbalance phenomenon of the above-mentioned photovoltaic system, it is found through research that the photovoltaic inverter has a three-phase imbalance adjustment function similar to the three-phase imbalance adjustment device (Smart Power Quality Correct Device, SPC). Therefore, during the actual operation of the photovoltaic system, the photovoltaic system can be adjusted for three-phase imbalance through the photovoltaic inverter. Considering that the photovoltaic inverter is mainly used to achieve power transmission during actual operation, that is, to convert direct current into alternating current and transmit it to the AC power grid, when using the photovoltaic inverter for three-phase imbalance adjustment, it is necessary to perform it under the condition that the photovoltaic inverter meets the power transmission capacity.

[0053] Based on the above considerations, the technical solution of the present application provides a method for operating a photovoltaic system, so as to use a photovoltaic inverter to perform three-phase unbalance adjustment when the photovoltaic inverter is in power transmission. In this solution, when the photovoltaic inverter of the photovoltaic system is in power transmission state, that is, the direct current generated by the photovoltaic components of the photovoltaic system is converted into alternating current, and transmitted to the alternating current grid to power the electrical equipment, if it is judged that the photovoltaic system meets the three-phase unbalance adjustment conditions, not only the three-phase current on the grid side can be obtained, but also the inverter three-phase current when the photovoltaic inverter is transmitting power. Then, the working mode of the photovoltaic inverter is analyzed and determined in combination with the current operating state parameters of the photovoltaic inverter. Finally, when the photovoltaic inverter is in the busy working mode, the phase current compensation is performed on the photovoltaic inverter in combination with the preset margin parameters of the photovoltaic inverter, and the obtained three-phase current on the grid side and the inverter three-phase current, so as to adjust the three-phase imbalance of the photovoltaic system.

[0054] Through the technical solution of the embodiment of the present application, when the photovoltaic inverter is in power transmission operation, the phase current compensation of the photovoltaic inverter can be performed in combination with the preset margin parameters of the photovoltaic inverter and the three-phase current on the grid side and the inverter three-phase current. Thus, the three-phase imbalance adjustment of the photovoltaic system can be achieved through the photovoltaic inverter while maintaining the stable power transmission operation of the photovoltaic inverter.

[0055] The photovoltaic system operation method provided in the embodiment of the present application is applied in Figure 1 In the photovoltaic system shown, the photovoltaic system includes a photovoltaic module 101, a photovoltaic inverter 103, an AC power grid 105 and a controller 107. The photovoltaic inverter 103 is arranged between the photovoltaic module 101 and the AC power grid 105, and is used to convert the DC power generated by the photovoltaic module 101 into AC power, and transmit it to the AC power grid 105 for use. The photovoltaic inverter 103 is connected to the controller 107, and the photovoltaic system operation method of the embodiment of the present application is executed by the controller 107.

[0056] Furthermore, the photovoltaic components 101 of the photovoltaic system can also be connected to the energy storage system through a DC-DC converter, etc. The DC power generated by the photovoltaic components 101 is converted into DC power suitable for the energy storage system, stored in the energy storage module of the energy storage system, and transmitted to the AC power grid 105 or other electrical equipment for use when there is a subsequent demand.

[0057] See also Figure 2 The present application provides a photovoltaic system operation method, including step 202, step 204 and step 206.

[0058] Step 202: When the photovoltaic system meets the three-phase unbalanced regulation condition, the grid-side three-phase current of the photovoltaic system and the inverter three-phase current of the photovoltaic inverter in the photovoltaic system are obtained.

[0059] Specifically, the photovoltaic system is an electric power system that converts light energy into electrical energy and uses it. Figure 1 The three-phase unbalance adjustment condition is the condition that needs to be met when the photovoltaic system triggers the three-phase unbalance adjustment. Specifically, the three-phase unbalance can be a three-phase voltage unbalance or a three-phase current unbalance. In order to facilitate the understanding of the technical solution of the present application, the following embodiments are explained by taking the three-phase current unbalance as an example.

[0060] The three-phase current on the grid side is the three-phase current value at the output end of the AC grid when the photovoltaic inverter transmits the converted AC power to the AC grid. The inverter three-phase current is the current value of the three-phase bridge arm of the photovoltaic inverter during operation.

[0061] It is understandable that the controller is not the only way to obtain the three-phase current on the grid side and the inverter three-phase current. In a more detailed embodiment, a measurement unit (such as a current sensor, a current transformer, etc.) may be set on the three-phase bridge arm of the AC grid side or the photovoltaic inverter, and the current may be obtained through the measurement unit. In another embodiment, the three-phase voltage on the AC grid side or the photovoltaic inverter may be collected and further calculated in combination with the three-phase voltage, which is not specifically limited.

[0062] Step 204: Determine the working mode of the photovoltaic inverter according to the current operating state parameters of the photovoltaic inverter.

[0063] Specifically, the current operating state parameters are various parameters related to the operation of the photovoltaic inverter when the photovoltaic inverter is operating in the current state. The current operating state parameters can be the parameters of the photovoltaic inverter itself or the operating environment parameters of the photovoltaic inverter, which can be selected in combination with actual needs. When the controller determines that the photovoltaic system meets the three-phase unbalanced adjustment conditions, it is necessary to further determine the working mode of the photovoltaic inverter to perform three-phase unbalanced adjustment in combination with the actual working mode.

[0064] It should be noted that the type of current operating state parameter is not unique. In one embodiment, it may be the operating voltage, operating current, operating power, etc. that change as the photovoltaic inverter is in different operating states during the operation of the photovoltaic inverter. In another embodiment, the current operating state parameter may also be the time point at which the photovoltaic inverter is running, such as the time point corresponding to the daytime, the time point corresponding to the night, etc., which can be selected in combination with actual needs, as long as it can distinguish the different power transmission states of the photovoltaic inverter.

[0065] Step 206, when the photovoltaic inverter is in the busy working mode, phase current compensation is performed on the photovoltaic inverter according to the three-phase current on the grid side, the inverter three-phase current, and the preset margin parameters of the photovoltaic inverter to adjust the three-phase imbalance of the photovoltaic system.

[0066] Specifically, the busy-hour working mode refers to the operating mode in which the photovoltaic system has a high photoelectric conversion capacity and the photovoltaic inverter needs to continuously convert a large amount of DC power into AC power and transmit it. For example, in a more detailed embodiment, when the photovoltaic inverter is operating during the day, it is considered that the photovoltaic inverter is operating in the busy-hour working mode. The preset margin parameter is the preset limit value that the three-phase electrical parameters of the photovoltaic inverter can reach when the photovoltaic inverter meets the power transmission demand.

[0067] In the busy working mode, the photovoltaic inverter must first meet the power transmission demand, and on this basis, reserve a certain margin for three-phase imbalance adjustment. In the scheme of this embodiment, when the controller uses the photovoltaic inverter to manage the three-phase imbalance, it is necessary to combine the preset margin parameters of the photovoltaic inverter to perform phase current compensation to adjust the three-phase imbalance of the photovoltaic inverter, so that the three-phase current of the photovoltaic inverter is in a three-phase balanced state, and the three-phase current imbalance is managed. That is, through this scheme, while meeting the power generation demand of the photovoltaic system, considering the margin allowed by the photovoltaic system for output, the photovoltaic inverter is partially controlled to be put into operation for three-phase imbalance adjustment, and while managing the three-phase imbalance of the current, large-scale abandonment of light will not occur.

[0068] In the above scheme, when the photovoltaic inverter of the photovoltaic system is in the power transmission state, that is, the direct current generated by the photovoltaic components of the photovoltaic system is converted into alternating current and transmitted to the alternating current grid to supply power to the electrical equipment, if it is judged that the photovoltaic system meets the three-phase unbalance adjustment conditions, not only the three-phase current on the grid side can be obtained, but also the inverter three-phase current when the photovoltaic inverter is transmitting power. Then, the current operating state parameters of the photovoltaic inverter are further combined to analyze and determine the working mode of the photovoltaic inverter. Finally, when the photovoltaic inverter is in the busy working mode, the phase current compensation of the photovoltaic inverter is performed in combination with the preset margin parameters of the photovoltaic inverter, and the obtained three-phase current on the grid side and the inverter three-phase current, so as to adjust the three-phase imbalance of the photovoltaic system. Through this scheme, when the photovoltaic inverter is transmitting power, the phase current compensation of the photovoltaic inverter can be performed in combination with the preset margin parameters of the photovoltaic inverter and the three-phase current on the grid side and the inverter three-phase current. Thereby, the three-phase imbalance adjustment of the photovoltaic system is realized through the photovoltaic inverter while maintaining the stable power transmission operation of the photovoltaic inverter.

[0069] See also Figure 3 In some embodiments, phase current compensation is performed on the photovoltaic inverter according to the three-phase current on the grid side, the inverter three-phase current, and the preset margin parameters of the photovoltaic inverter, including step 302, step 304 and step 306.

[0070] Step 302: Determine the current regulation mode required by the photovoltaic inverter according to the three-phase current on the grid side, the inverter three-phase current, and the preset margin parameters of the photovoltaic inverter.

[0071] Step 304 : when the required current regulation mode is the current boost margin regulation mode, the minimum phase current in the inverter three-phase current is compensated.

[0072] Step 306 : When the required current regulation mode is the current reduction margin regulation mode, the maximum phase current in the inverter three-phase current is compensated.

[0073] Specifically, the current regulation mode is a different mode that requires increasing or reducing the phase current to adjust the three-phase current imbalance under the current grid-side three-phase current and inverter three-phase current. The current increase margin adjustment mode is an operating mode when the photovoltaic inverter has a current increase margin and the phase current of the photovoltaic inverter is increased to achieve current compensation. The current reduction margin adjustment mode is an operating mode corresponding to the current compensation when the photovoltaic inverter has a current reduction margin and the phase current of the photovoltaic inverter is reduced to achieve current compensation.

[0074] In different current regulation modes, the phase of the photovoltaic inverter that needs to be compensated is also different. If the current regulation mode is the current boost margin regulation mode, it means that there is a certain boost margin in the inverter three-phase current. At this time, in order to reduce the imbalance of the three-phase current, that is, to narrow the gap between the three-phase currents, the controller will compensate for the minimum phase current in the inverter three-phase current, that is, by controlling the operating parameters of the photovoltaic inverter, the current value of the phase corresponding to the minimum phase current is increased.

[0075] If the current regulation mode is the current reduction margin regulation mode, it means that there is a certain reduction margin for the inverter three-phase current. At this time, in order to reduce the imbalance of the three-phase current, that is, to narrow the gap between the three-phase currents, the controller will compensate for the maximum phase current in the inverter three-phase current, that is, by controlling the operating parameters of the photovoltaic inverter, reduce the current value of the phase corresponding to the minimum phase current.

[0076] It should be noted that the controller is not the only way to compensate the phase current of the photovoltaic inverter. In a more detailed embodiment, it can be achieved by changing the duty cycle of the phase current corresponding to the bridge arm in the photovoltaic inverter. Specifically, the phase current of the corresponding phase of the bridge arm can be increased by increasing the duty cycle of a bridge arm, that is, increasing the conduction time of the switch device in the bridge arm; the phase current of the corresponding phase of the bridge arm can be reduced by reducing the duty cycle of a bridge arm.

[0077] It can be understood that when compensating for the maximum phase current or the minimum phase current in the photovoltaic inverter, the specific current value that needs to be compensated needs to be set in combination with the three-phase balance of the photovoltaic system in the actual scenario. In the case of a large three-phase imbalance, the corresponding current value that needs to be compensated will also be higher. For example, a corresponding relationship between the three-phase imbalance and the compensation current can be established. In the actual scenario, the three-phase imbalance of the current photovoltaic system is substituted into the corresponding relationship for analysis, and the current value that needs to be compensated in the current scenario can be determined, so that the bridge arm duty cycle can be adjusted.

[0078] The above scheme can be combined with the actual situation of the photovoltaic inverter to compensate for the minimum phase current or the maximum phase current of the photovoltaic inverter, thereby reducing the three-phase imbalance and having high current compensation control reliability.

[0079] See also Figure 4 In some embodiments, the preset margin parameters include a preset current boost threshold and a preset maximum allowable current; step 302 includes step 402 and step 404 .

[0080] Step 402, obtaining the current sum of the minimum phase current in the inverter three-phase current and the preset current boost threshold.

[0081] Step 404: when the minimum phase current among the three-phase currents on the grid side is greater than the current sum and less than the preset maximum allowable current, determine that the required current regulation mode is the current boost margin regulation mode.

[0082] Specifically, the preset current boost threshold is the preset maximum current value allowed to be boosted by the three-phase current of the photovoltaic inverter when the photovoltaic inverter is in busy working mode. The preset maximum allowable current is the current upper limit value set to prevent the photovoltaic components of the photovoltaic system from abandoning light when the photovoltaic inverter is in busy working mode. After the controller obtains the three-phase current on the grid side and the inverter three-phase current, it will analyze I min_phase +I up_threshold min max_allowed Is it true, where I min_phase Indicates the minimum phase current in the inverter three-phase current, I up_threshold Indicates the preset current boost threshold, I min Indicates the minimum phase current among the three-phase currents on the grid side, I max_allowed Indicates the preset maximum allowable current. If the above formula is established after analysis, it means that the photovoltaic inverter has a current boost margin. At this time, it is in the current boost margin adjustment mode, which can compensate for the minimum phase current in the inverter three-phase current to reduce the three-phase imbalance.

[0083] The above scheme can combine the preset current boost threshold, the preset maximum allowable current, the minimum phase current of the three-phase current on the grid side and the minimum phase current of the inverter three-phase current to determine whether the photovoltaic inverter is in the current boost margin adjustment mode, and has a high accuracy in determining the current boost margin adjustment mode.

[0084] See also Figure 5 In some embodiments, the preset margin parameters include a preset current reduction threshold and a preset minimum allowed current; step 302 includes step 502 and step 504 .

[0085] Step 502: Obtain a current difference between a maximum phase current in the inverter three-phase current and a preset current reduction threshold.

[0086] ​​Step 504 , when the preset minimum allowable current is greater than the maximum phase current among the three-phase currents on the grid side and less than the current difference, determine that the required current regulation mode is the current reduction margin regulation mode.

[0087] Specifically, the preset current reduction threshold is the maximum current value that the three-phase current of the photovoltaic inverter is allowed to reduce when the photovoltaic inverter is in the busy working mode. The preset minimum allowable current is the lower limit of the operating current set to prevent the photovoltaic components of the photovoltaic system from abandoning light when the photovoltaic inverter is in the busy working mode. After the controller obtains the three-phase current on the grid side and the inverter three-phase current, it will analyze I max min_allowed max_phase -I down_threshold Is it true, where I max The maximum phase current among the three-phase currents on the grid side, I max_phase Indicates the maximum phase current in the inverter three-phase current, I min_allowed Indicates the preset minimum allowable current, I down_threshold Indicates the preset current reduction threshold. If the above formula is established after analysis, it means that the photovoltaic inverter has a current reduction margin. At this time, it is in the current reduction margin adjustment mode, which can compensate for the maximum phase current in the inverter three-phase current to reduce the three-phase imbalance.

[0088] The above scheme can combine the preset current reduction threshold, the preset minimum allowable current, the maximum phase current of the three-phase current on the grid side and the maximum phase current of the inverter three-phase current to determine whether the photovoltaic inverter is in the current reduction margin adjustment mode, and has a high accuracy in determining the current reduction margin adjustment mode.

[0089] It should be noted that in the above embodiments, the values ​​of the preset current reduction threshold and the preset current increase threshold are not unique, and can be set in combination with the type of photovoltaic inverter in the actual scenario or the specific situation of the photovoltaic system, and are not specifically limited. The preset current reduction threshold and the preset current increase threshold can be set to be the same or different. For example, in a more detailed embodiment, the preset current reduction threshold and the preset current increase threshold can be set to be less than or equal to 5% of the rated current value of the photovoltaic inverter.

[0090] The preset maximum allowable current and the preset minimum allowable current of the photovoltaic inverter are also not unique, and may vary depending on the type of photovoltaic inverter. Specifically, in one embodiment, the preset maximum allowable current and the preset minimum allowable current may be measured and given when the photovoltaic inverter leaves the factory.

[0091] ​​In some embodiments, when the photovoltaic inverter is in a busy working mode, it also includes: when it is determined that the three-phase imbalance regulation capacity of the photovoltaic inverter is exceeded based on the three-phase current on the grid side, the inverter three-phase current, and the preset margin parameters of the photovoltaic inverter, controlling the three-phase imbalance regulation device of the photovoltaic system to adjust the three-phase imbalance of the photovoltaic system.

[0092] Specifically, the three-phase imbalance degree of the photovoltaic system is exceeded when the photovoltaic inverter's three-phase imbalance adjustment capability is exceeded. In this state, the three-phase imbalance problem can no longer be solved by adjusting the inverter three-phase current of the photovoltaic inverter. Therefore, when the controller analysis shows that the photovoltaic inverter's three-phase imbalance adjustment capability is exceeded, the photovoltaic system needs to use an additional three-phase imbalance adjustment device to adjust the three-phase imbalance.

[0093] It should be noted that the way in which the controller determines whether the three-phase unbalanced regulation capability of the photovoltaic inverter is exceeded based on the three-phase current on the grid side, the three-phase inverter current, and the preset margin parameters of the photovoltaic inverter is not the only one. In one embodiment, the controller may analyze the three-phase current on the grid side, the three-phase inverter current, and the preset margin parameters of the photovoltaic inverter. At this time, when the photovoltaic inverter has neither a current reduction margin nor a current increase margin, it is considered that the three-phase unbalanced regulation capability of the photovoltaic inverter is exceeded.

[0094] Specifically, in one embodiment, it can be that in I min_phase +I up_threshold min max_allowed with I max min_allowed max_phase -I down_threshold If neither condition holds true, it is deemed that the three-phase unbalance regulation capability of the photovoltaic inverter has been exceeded.

[0095] In the above scheme, when the photovoltaic inverter is in the busy working mode, if the three-phase current on the grid side, the inverter three-phase current, and the preset margin parameters of the photovoltaic inverter are combined, it is judged that the three-phase imbalance at this time exceeds the three-phase imbalance adjustment capability of the photovoltaic inverter. By turning on the three-phase imbalance adjustment device to perform three-phase imbalance adjustment, the reliability of the three-phase imbalance adjustment is improved.

[0096] In some embodiments, when the photovoltaic inverter is in busy working mode, it also includes: predicting the future required phase sequence of the photovoltaic inverter based on the historical cumulative power generation and historical phase sequence of each phase of the photovoltaic inverter; and controlling the photovoltaic inverter to adjust the phase sequence according to the future required phase sequence.

[0097] ​​​​Specifically, the historical cumulative power generation and historical phase sequence of each phase refer to: the cumulative power generation of the three phases of the photovoltaic inverter under the historical operating state (that is, the cumulative conversion of DC to AC), and the phase sequence changes of each phase during the historical operating time period. The required phase sequence in the future is the phase state corresponding to the three-phase bridge arm of the photovoltaic inverter in a future operating time period (which can be the next day or the next hour, etc., without specific limitation).

[0098] It should be pointed out that the method of predicting the future required phase sequence of the photovoltaic inverter is not unique. In a more detailed embodiment, the controller pre-stores a relevant prediction model. When the photovoltaic inverter is in the busy working mode, the controller can combine the cumulative power generation and the historical phase sequence corresponding to the three phases of the photovoltaic inverter to perform prediction analysis to obtain the phase sequence required in the future time period, so as to control the operation of the photovoltaic inverter in the future time period. In this way, the photovoltaic inverter can perform phase change in advance according to the future required phase sequence, thereby improving the operating efficiency of the photovoltaic inverter.

[0099] It is understandable that the specific type of prediction model is not unique. For example, in a more detailed embodiment, an LSTM (Long Short-Term Memory) model can be used to predict the future required phase sequence.

[0100] The above scheme, when the photovoltaic inverter is in the busy working mode, can further predict the future required phase sequence based on the historical cumulative power generation and historical phase sequence of each phase in the photovoltaic inverter. The photovoltaic inverter will operate with the future required phase sequence at future moments, which can reduce the possibility of the photovoltaic inverter continuing to operate with the same phase sequence, alleviate the loss of the photovoltaic inverter to a certain extent, and improve the operating efficiency of the photovoltaic inverter.

[0101] See also Figure 6 In some embodiments, after step 204 , the method further includes step 602 .

[0102] Step 602: When the photovoltaic inverter is in an idle working mode, phase current compensation is performed on the grid side of the photovoltaic system to adjust the three-phase imbalance of the photovoltaic system.

[0103] Specifically, the idle working mode refers to the operating mode in which the photovoltaic system is in a lower photoelectric conversion capacity, and the photovoltaic inverter does not need to continuously convert DC power into AC power and transmit it. For example, in a more detailed embodiment, when the photovoltaic inverter is operating at night, it can be determined that the photovoltaic inverter is operating in the idle working mode. In the idle working mode, the photovoltaic inverter can be fully invested in three-phase imbalance management. Therefore, in the scheme of this embodiment, the control combines the three-phase current on the grid side to perform phase current compensation on the grid side. There is no need to consider the reserved margin of the photovoltaic inverter, that is, there is no need to consider the preset margin parameters of the photovoltaic inverter, and the three-phase current on the grid side can be directly compensated.

[0104] It should be pointed out that the compensation method of the three-phase current on the grid side is not unique. In one embodiment, since the AC grid is connected to the photovoltaic module through a photovoltaic inverter, the compensation adjustment of the three-phase current on the grid side can be indirectly achieved by adjusting the three-phase current of the photovoltaic inverter.

[0105] The above scheme fully puts the photovoltaic inverter into three-phase unbalanced regulation when the photovoltaic inverter is in the idle working mode, without considering the inverter three-phase current and preset margin parameters of the photovoltaic inverter, thereby improving the three-phase unbalanced regulation capability of the photovoltaic inverter.

[0106] See also Figure 7 In some embodiments, phase current compensation is performed on the grid side of the photovoltaic system, including step 702, step 704 and step 706.

[0107] Step 702: Determine the current compensation mode required by the grid side of the photovoltaic system according to the three-phase current of the grid side.

[0108] Step 704: When the required current compensation mode is upward compensation, the minimum phase current in the inverter three-phase current is adjusted to compensate for the minimum phase current on the grid side.

[0109] Step 706: When the required current compensation mode is downward compensation, the maximum phase current in the inverter three-phase current is adjusted to compensate for the minimum large phase current on the grid side.

[0110] Specifically, the current compensation mode is a specific adjustment method for adjusting the three-phase current on the grid side to reduce the three-phase imbalance. Upward compensation is a regulation mode for reducing the three-phase imbalance by increasing the three-phase current on the grid side. Downward compensation is a regulation mode for reducing the three-phase imbalance by reducing the three-phase current on the grid side. When the controller determines that the required current compensation mode is upward compensation in combination with the three-phase current on the grid side, it can increase the minimum phase current in the inverter three-phase current to indirectly increase the minimum corresponding current value in the three-phase current on the grid side, that is, compensate for the minimum phase current in the three-phase current on the grid side, and achieve three-phase imbalance adjustment. If the required current compensation mode is downward compensation, it can indirectly reduce the maximum corresponding current value in the three-phase current on the grid side by reducing the maximum phase current in the inverter three-phase current, that is, compensate for the maximum phase current in the three-phase current on the grid side, and achieve three-phase imbalance adjustment.

[0111] The above scheme can be combined with the actual situation of the photovoltaic inverter to compensate for the minimum phase current or maximum phase current of the photovoltaic inverter, thereby changing the corresponding phase current in the three-phase current on the grid side, realizing three-phase unbalanced regulation, and has high current compensation control reliability.

[0112] See also Figure 8 In some embodiments, step 702 includes step 802 , step 804 , step 806 , and step 808 .

[0113] Step 802, obtaining the average value of each phase current in the three-phase current on the grid side.

[0114] Step 804, determining a first difference between a maximum phase current and an average value of the three-phase current on the grid side, and a second difference between the average value and a minimum phase current of the three-phase current on the grid side.

[0115] Step 806: When the first difference is greater than the second difference, determine that the current compensation mode required by the photovoltaic inverter is upward compensation.

[0116] Step 808 : When the first difference is less than or equal to the second difference, determine that the current compensation mode required by the photovoltaic inverter is downward compensation.

[0117] Specifically, when the photovoltaic inverter is in the idle working mode, the controller calculates the mean value of the current values ​​corresponding to the three phases in the three-phase current of the grid side to obtain the average value. Then, it is determined whether I max -I avg >I avg -I min , where I max Indicates the maximum phase current among the three-phase currents on the grid side, I avg represents the average value, I minIndicates the minimum phase current among the three-phase currents on the grid side. If the relationship holds, it is considered that the current compensation mode required by the photovoltaic inverter is upward compensation, otherwise it is considered that the current compensation mode required by the photovoltaic inverter is downward compensation.

[0118] The above scheme first obtains the average value of each phase current in the three-phase current on the grid side, and then determines the current compensation mode required by the photovoltaic inverter based on the relationship between the difference between the maximum phase current and the average value, and the difference between the average value and the minimum phase current in the three-phase current on the grid side. It has a high accuracy in determining the current compensation mode.

[0119] In some embodiments, when the photovoltaic inverter is in an idle working mode, it also includes: obtaining the cumulative power generation of each phase of the photovoltaic inverter; selecting the phase with the smallest cumulative power generation as the adjustment phase to change the phase sequence of the photovoltaic inverter.

[0120] Specifically, the cumulative power generation of each phase is the conversion amount of direct current to alternating current accumulated by each phase of the photovoltaic inverter within a certain period of time. The cumulative power generation of each phase can be calculated by the phase current, phase voltage and cumulative operation time of each phase, that is, the product of the phase current, phase voltage and cumulative operation time of each phase is used as the cumulative power generation. During the operation of the photovoltaic inverter, the controller analyzes the cumulative power generation of each phase of the photovoltaic inverter in real time, selects the phase with the smallest cumulative power generation as the adjustment reference, and changes the phase sequence of the photovoltaic inverter. That is, at least the corresponding phase sequence with the smallest cumulative power generation is adjusted with the phase sequence of another phase; further, in one embodiment, the phase sequence of the three phases can also be adjusted, which can be selected in combination with actual needs. In this way, the corresponding phase sequence with the smallest cumulative power generation is changed to other phase sequences, and the phase with lower loss is allowed to participate in the unbalanced current management work through the dynamic phase change method, which balances the three-phase loss of the photovoltaic inverter and can extend the service life of the photovoltaic inverter.

[0121] In the above scheme, when the photovoltaic inverter is in the idle working mode, the phase with the smallest cumulative power generation can be selected as the adjustment phase to adjust the phase sequence according to the cumulative power generation of each phase in the photovoltaic inverter, so as to balance the three-phase loss of the photovoltaic inverter.

[0122] In some embodiments, the photovoltaic system satisfies the three-phase unbalance adjustment condition, including: determining the three-phase unbalance degree of the photovoltaic system according to the three-phase electrical parameters on the grid side of the photovoltaic system; and determining that the photovoltaic system satisfies the three-phase unbalance adjustment condition when the three-phase unbalance degree is greater than a preset threshold.

[0123] Specifically, the three-phase electrical parameters on the grid side can be the three-phase voltage parameters on the grid side or the three-phase current parameters on the grid side. Under actual operating conditions, the measurement unit in the photovoltaic system will regularly measure the three-phase current or three-phase voltage on the grid side to calculate the three-phase imbalance of the photovoltaic system. When the three-phase imbalance is greater than a preset threshold, it is considered that the three-phase imbalance of the photovoltaic system is too high and three-phase imbalance adjustment needs to be started.

[0124] It can be understood that the calculation method of the three-phase imbalance is not unique. In a more detailed embodiment, taking the three-phase electrical parameter of the grid side as the three-phase current of the grid side as an example, the controller can combine the three-phase current of the grid side to obtain the maximum phase current I max With the minimum phase current I min and through The three-phase imbalance η is calculated. If the absolute value of the calculated three-phase imbalance η is greater than the preset threshold η th (According to the national standard for power quality, it is generally set at 7%-10%. Users can set a smaller or larger preset threshold based on actual power quality requirements, and there is no specific limitation), then the three-phase unbalanced current management process is started.

[0125] In other embodiments, the average value I of each phase current can be obtained by combining the three-phase current on the grid side. avg , then select each phase current and the average value I avg The maximum absolute value of the difference between the maximum value and the average value I avg ratio, as the three-phase unbalance degree.

[0126] The above scheme determines whether the photovoltaic system meets the three-phase imbalance adjustment conditions through the three-phase imbalance degree determined by the grid-side three-phase electrical parameters of the photovoltaic inverter and the preset threshold, and has high judgment efficiency and judgment accuracy.

[0127] In order to facilitate understanding of the technical solution of the present application, the present application is explained below in conjunction with a more detailed embodiment. The photovoltaic inverter working during the day is considered to be in a busy working mode, and the photovoltaic inverter working at night is considered to be in an idle working mode.

[0128] If the PV inverter works in the busy working mode (daytime), the measurement unit set in the PV system will regularly measure the three-phase current on the grid side to obtain the maximum phase current I max With the minimum phase current I min And the three-phase current unbalance η is calculated by the following formula: When the absolute value of the calculated imbalance η is greater than the preset threshold η th, then the three-phase unbalanced current management process starts. After starting the management process, the controller locates the maximum current phase and minimum current phase of the photovoltaic inverter according to the inverter three-phase current of the photovoltaic inverter, and manages it in the following way: If the current value corresponding to the minimum current of the photovoltaic inverter I min_phase Satisfaction: I min_phase +I up_threshold min max_allowed , indicating that the photovoltaic inverter has a current boost margin. At this time, it is in the current boost margin adjustment mode, which can compensate for the minimum phase current in the inverter three-phase current to reduce the three-phase imbalance. Among them, I min_phase Indicates the minimum phase current in the inverter three-phase current, I up_threshold Indicates the preset current boost threshold, I min Indicates the minimum phase current among the three-phase currents on the grid side, I max_allowed Indicates the preset maximum allowable current.

[0129] If the photovoltaic inverter has no current increase margin, then consider the current value I corresponding to the maximum current of the photovoltaic inverter max_phase Satisfied: I max min_αllowed max_phase -I down_threshold Among them, I max The maximum phase current among the three-phase currents on the grid side, I max_phase Indicates the maximum phase current in the inverter three-phase current, I min_allowed Indicates the preset minimum allowable current, I down_threshold Indicates the preset current reduction threshold. If this formula is established, it means that the photovoltaic inverter has a current reduction margin. At this time, it is in the current reduction margin adjustment mode, and the maximum phase current in the inverter three-phase current can be compensated to reduce the three-phase imbalance. If the above two conditions cannot be met through analysis, it means that the three-phase imbalance of the photovoltaic system has exceeded the three-phase imbalance adjustment capability of the photovoltaic inverter during power transmission, and other adjustment methods are needed, such as SPC.

[0130] At the same time, in the busy working mode, the controller uses the LSTM model to predict the future required phase sequence of the photovoltaic inverter based on the historical cumulative power generation and historical phase sequence of each phase of the photovoltaic inverter, and controls the photovoltaic inverter to adjust the phase sequence according to the future required phase sequence.

[0131] If the PV inverter works in the idle working mode (at night), the controller uses the same method to calculate the three-phase imbalance. th ​​​​In this process, the measurement unit set up in the photovoltaic system will regularly measure the three-phase current on the grid side and obtain the average value of the three-phase current I avg , Maximum phase current I max With the minimum phase current I min . Then analyze whether it satisfies I max -I avg >I avg -I min If it is satisfied, it is considered that the current compensation mode required by the photovoltaic inverter is upward compensation. At this time, the minimum phase current I min If the current value of the corresponding phase is not satisfied, it is considered that the current compensation mode required by the photovoltaic inverter is downward compensation, and the maximum phase current I max The current value of the corresponding phase.

[0132] At the same time, in the idle working mode, the controller will analyze the cumulative power generation of each phase of the photovoltaic inverter in real time, select the phase with the smallest cumulative power generation as the adjustment basis, and change the phase sequence of the photovoltaic inverter. The corresponding phase sequence with the smallest cumulative power generation is changed to other phase sequences, and the phase with lower loss is allowed to participate in the unbalanced current management through the dynamic phase change method, which balances the three-phase loss of the photovoltaic inverter and can extend the service life of the photovoltaic inverter.

[0133] 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.

[0134] Based on the same inventive concept, the embodiment of the present application also provides a photovoltaic system operation device for implementing the photovoltaic system operation method involved above. The implementation solution provided by the device to solve the problem is similar to the implementation solution recorded in the above method, so the specific limitations in one or more photovoltaic system operation device embodiments provided below can refer to the limitations of the photovoltaic system operation method above, and will not be repeated here.

[0135] See also Fig. 9, a photovoltaic system operating device includes a phase current acquisition module 902, a working mode determination module 904 and an imbalance adjustment module 906.

[0136] The phase current acquisition module 902 is used to obtain the grid-side three-phase current of the photovoltaic system and the inverter three-phase current of the photovoltaic inverter in the photovoltaic system when the photovoltaic system meets the three-phase unbalance adjustment conditions; the working mode determination module 904 is used to determine the working mode of the photovoltaic inverter according to the current operating state parameters of the photovoltaic inverter; the imbalance adjustment module 906 is used to perform phase current compensation on the photovoltaic inverter according to the grid-side three-phase current, the inverter three-phase current, and the preset margin parameters of the photovoltaic inverter when the photovoltaic inverter is in the busy working mode, so as to adjust the three-phase imbalance of the photovoltaic system.

[0137] In some embodiments, the imbalance adjustment module 906 is also used to determine the current regulation mode required by the photovoltaic inverter based on the three-phase current on the grid side, the inverter three-phase current, and the preset margin parameters of the photovoltaic inverter; when the required current regulation mode is the current increase margin adjustment mode, the minimum phase current in the inverter three-phase current is compensated; when the required current regulation mode is the current reduction margin adjustment mode, the maximum phase current in the inverter three-phase current is compensated.

[0138] In some embodiments, the imbalance adjustment module 906 is also used to obtain the current sum of the minimum phase current in the inverter three-phase current and the preset current boost threshold; when the minimum phase current in the three-phase current on the grid side is greater than the current sum and less than the preset maximum allowable current, it is determined that the required current adjustment mode is the current boost margin adjustment mode.

[0139] In some embodiments, the imbalance adjustment module 906 is also used to obtain the current difference between the maximum phase current in the inverter three-phase current and the preset current reduction threshold; when the preset minimum allowable current is greater than the maximum phase current in the three-phase current on the grid side and less than the current difference, it is determined that the required current adjustment mode is the current reduction margin adjustment mode.

[0140] In some embodiments, the imbalance adjustment module 906 is also used to control the three-phase imbalance adjustment device of the photovoltaic system to adjust the three-phase imbalance of the photovoltaic system when it is determined that the three-phase imbalance adjustment capacity of the photovoltaic inverter is exceeded based on the three-phase current on the grid side, the inverter three-phase current, and the preset margin parameters of the photovoltaic inverter.

[0141] See also Fig.10 In some embodiments, the photovoltaic system operating device further includes a phase sequence adjustment module 1002 .

[0142] The phase sequence adjustment module 1002 is used to predict the future required phase sequence of the photovoltaic inverter according to the historical accumulated power generation of each phase of the photovoltaic inverter and the historical phase sequence; and control the photovoltaic inverter to adjust the phase sequence according to the future required phase sequence.

[0143] In some embodiments, the imbalance adjustment module 906 is further configured to perform phase current compensation on the grid side of the photovoltaic system when the photovoltaic inverter is in an idle working mode, so as to adjust the three-phase imbalance of the photovoltaic system.

[0144] In some embodiments, the imbalance adjustment module 906 is also used to determine the current compensation mode required on the grid side of the photovoltaic system based on the three-phase current on the grid side; when the required current compensation mode is upward compensation, the minimum phase current in the inverter three-phase current is adjusted to compensate for the minimum phase current on the grid side; when the required current compensation mode is downward compensation, the maximum phase current in the inverter three-phase current is adjusted to compensate for the minimum large phase current on the grid side.

[0145] In some embodiments, the imbalance adjustment module 906 is also used to obtain the average value of each phase current in the three-phase current on the grid side; determine a first difference between the maximum phase current and the average value of the three-phase current on the grid side, and a second difference between the average value and the minimum phase current of the three-phase current on the grid side; when the first difference is greater than the second difference, determine that the current compensation mode required by the photovoltaic inverter is upward compensation; when the first difference is less than or equal to the second difference, determine that the current compensation mode required by the photovoltaic inverter is downward compensation.

[0146] In some embodiments, the phase sequence adjustment module 1002 is further used to obtain the cumulative power generation of each phase of the photovoltaic inverter; and select the phase with the smallest cumulative power generation as the adjustment phase to change the phase sequence of the photovoltaic inverter.

[0147] See also Fig.11 In some embodiments, the photovoltaic system operation device further includes an unbalance determination module 112. The unbalance determination module 112 is used to determine the three-phase unbalance of the photovoltaic system according to the grid-side three-phase electrical parameters of the photovoltaic system; when the three-phase unbalance is greater than a preset threshold, it is determined that the photovoltaic system meets the three-phase unbalance adjustment condition.

[0148] Each module in the photovoltaic system operation 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.

[0149] Please refer to Figure 1A photovoltaic system includes a photovoltaic module 101, a photovoltaic inverter 103, an AC power grid 105 and a controller 107. The photovoltaic inverter 103 is arranged between the photovoltaic module 101 and the AC power grid 105. The photovoltaic inverter 103 is connected to the controller 107. The controller 107 is used to execute the steps of the above-mentioned photovoltaic system operation method.

[0150] Specifically, the photovoltaic system operation method is as shown in the above-mentioned embodiments and the accompanying drawings. When the photovoltaic inverter 103 is in the power transmission state, that is, the direct current generated by the photovoltaic components 101 of the photovoltaic system is converted into alternating current and transmitted to the alternating current grid 105 to power the electrical equipment, if it is judged that the photovoltaic system meets the three-phase unbalance adjustment conditions, not only the three-phase current on the grid side can be obtained, but also the inverter three-phase current when the photovoltaic inverter 103 transmits power can be obtained. Then, the current operating state parameters of the photovoltaic inverter 103 are further combined to analyze and determine the working mode of the photovoltaic inverter 103. Finally, when the photovoltaic inverter 103 is in the busy working mode, the phase current compensation is performed on the photovoltaic inverter 103 in combination with the preset margin parameters of the photovoltaic inverter 103, and the obtained three-phase current on the grid side and the inverter three-phase current, so as to adjust the three-phase imbalance of the photovoltaic system. Through this solution, when the photovoltaic inverter 103 is transmitting power, the phase current compensation of the photovoltaic inverter 103 can be performed in combination with the preset margin parameters of the photovoltaic inverter 103 and the three-phase current on the grid side and the inverter three-phase current. Thus, the three-phase imbalance adjustment of the photovoltaic system can be achieved through the photovoltaic inverter 103 while maintaining the stable power transmission operation of the photovoltaic inverter 103.

[0151] In one embodiment, a computer device is provided. The computer device may be a terminal controller, and its internal structure diagram may be as follows: Fig.12 As shown. The computer device includes a processor, a memory and a network interface connected through a system bus. 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 relevant data on the operation of the photovoltaic system. The network 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 system operation method is implemented.

[0152] Those skilled in the art will understand that Fig.12The 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.

[0153] In one 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, the following steps are implemented:

[0154] When the photovoltaic system meets the three-phase unbalanced regulation conditions, the grid-side three-phase current of the photovoltaic system and the inverter three-phase current of the photovoltaic inverter in the photovoltaic system are obtained; the photovoltaic inverter working mode is determined according to the current operating status parameters of the photovoltaic inverter; when the photovoltaic inverter is in the busy working mode, the photovoltaic inverter is compensated for the phase current according to the grid-side three-phase current, the inverter three-phase current, and the preset margin parameters of the photovoltaic inverter to adjust the three-phase imbalance of the photovoltaic system.

[0155] In one embodiment, the processor further implements the following steps when executing the computer program: determining the current regulation mode required for the photovoltaic inverter according to the three-phase current on the grid side, the inverter three-phase current, and the preset margin parameters of the photovoltaic inverter; when the required current regulation mode is the current increase margin regulation mode, compensating for the minimum phase current in the inverter three-phase current; when the required current regulation mode is the current reduction margin regulation mode, compensating for the maximum phase current in the inverter three-phase current.

[0156] In one embodiment, when the processor executes the computer program, it also implements the following steps: obtaining the current sum of the minimum phase current in the inverter three-phase current and the preset current boost threshold; when the minimum phase current in the three-phase current on the grid side is greater than the current sum and less than the preset maximum allowable current, determining that the required current regulation mode is the current boost margin regulation mode.

[0157] In one embodiment, when the processor executes the computer program, the following steps are also implemented: obtaining the current difference between the maximum phase current in the inverter three-phase current and a preset current reduction threshold; when the preset minimum allowable current is greater than the maximum phase current in the three-phase current on the grid side and less than the current difference, determining that the required current regulation mode is the current reduction margin regulation mode.

[0158] In one embodiment, when the processor executes the computer program, the following steps are also implemented: when it is determined that the three-phase unbalance adjustment capacity of the photovoltaic inverter is exceeded based on the three-phase current on the grid side, the inverter three-phase current, and the preset margin parameters of the photovoltaic inverter, the three-phase unbalance adjustment device of the photovoltaic system is controlled to adjust the three-phase imbalance of the photovoltaic system.

[0159] In one embodiment, when the processor executes the computer program, the following steps are also implemented: predicting the future required phase sequence of the photovoltaic inverter based on the historical accumulated power generation and historical phase sequence of each phase of the photovoltaic inverter; and controlling the photovoltaic inverter to adjust the phase sequence according to the future required phase sequence.

[0160] In one embodiment, when the processor executes the computer program, the following steps are further implemented: when the photovoltaic inverter is in an idle working mode, phase current compensation is performed on the grid side of the photovoltaic system to adjust the three-phase imbalance of the photovoltaic system.

[0161] In one embodiment, the processor also implements the following steps when executing the computer program: determining the current compensation mode required on the grid side of the photovoltaic system based on the three-phase current on the grid side; when the required current compensation mode is upward compensation, adjusting the minimum phase current in the inverter three-phase current to compensate for the minimum phase current on the grid side; when the required current compensation mode is downward compensation, adjusting the maximum phase current in the inverter three-phase current to compensate for the minimum large phase current on the grid side.

[0162] In one embodiment, when the processor executes the computer program, the following steps are also implemented: obtaining the average value of each phase current in the three-phase current on the grid side; determining a first difference between the maximum phase current and the average value of the three-phase current on the grid side, and a second difference between the average value and the minimum phase current of the three-phase current on the grid side; when the first difference is greater than the second difference, determining that the current compensation mode required by the photovoltaic inverter is upward compensation; when the first difference is less than or equal to the second difference, determining that the current compensation mode required by the photovoltaic inverter is downward compensation.

[0163] In one embodiment, when the processor executes the computer program, the following steps are also implemented: obtaining the cumulative power generation of each phase of the photovoltaic inverter; selecting the phase with the smallest cumulative power generation as the adjustment phase to change the phase sequence of the photovoltaic inverter.

[0164] In one embodiment, when the processor executes the computer program, the following steps are also implemented: determining the three-phase imbalance of the photovoltaic system based on the three-phase electrical parameters of the grid side of the photovoltaic system; when the three-phase imbalance is greater than a preset threshold, determining that the photovoltaic system meets the three-phase imbalance adjustment conditions.

[0165] In one embodiment, a computer readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, the following steps are implemented:

[0166] When the photovoltaic system meets the three-phase unbalanced regulation conditions, the grid-side three-phase current of the photovoltaic system and the inverter three-phase current of the photovoltaic inverter in the photovoltaic system are obtained; the photovoltaic inverter working mode is determined according to the current operating status parameters of the photovoltaic inverter; when the photovoltaic inverter is in the busy working mode, the photovoltaic inverter is compensated for the phase current according to the grid-side three-phase current, the inverter three-phase current, and the preset margin parameters of the photovoltaic inverter to adjust the three-phase imbalance of the photovoltaic system.

[0167] In one embodiment, when the computer program is executed by the processor, the following steps are also implemented: determining the current regulation mode required for the photovoltaic inverter based on the three-phase current on the grid side, the inverter three-phase current, and the preset margin parameters of the photovoltaic inverter; when the required current regulation mode is the current increase margin regulation mode, compensating for the minimum phase current in the inverter three-phase current; when the required current regulation mode is the current reduction margin regulation mode, compensating for the maximum phase current in the inverter three-phase current.

[0168] In one embodiment, when the computer program is executed by the processor, the following steps are also implemented: obtaining the current sum of the minimum phase current in the inverter three-phase current and the preset current boost threshold; when the minimum phase current in the three-phase current on the grid side is greater than the current sum and less than the preset maximum allowable current, determining that the required current regulation mode is the current boost margin regulation mode.

[0169] In one embodiment, when the computer program is executed by the processor, the following steps are also implemented: obtaining the current difference between the maximum phase current in the inverter three-phase current and a preset current reduction threshold; when the preset minimum allowable current is greater than the maximum phase current in the three-phase current on the grid side and less than the current difference, determining that the required current regulation mode is the current reduction margin regulation mode.

[0170] In one embodiment, when the computer program is executed by the processor, the following steps are also implemented: when it is determined that the three-phase unbalance adjustment capability of the photovoltaic inverter is exceeded based on the three-phase current on the grid side, the inverter three-phase current, and the preset margin parameters of the photovoltaic inverter, the three-phase unbalance adjustment device of the photovoltaic system is controlled to adjust the three-phase imbalance of the photovoltaic system.

[0171] In one embodiment, when the computer program is executed by the processor, the following steps are also implemented: predicting the future required phase sequence of the photovoltaic inverter based on the historical cumulative power generation and historical phase sequence of each phase of the photovoltaic inverter; and controlling the photovoltaic inverter to adjust the phase sequence according to the future required phase sequence.

[0172] In one embodiment, when the computer program is executed by the processor, the following steps are also implemented: when the photovoltaic inverter is in an idle working mode, phase current compensation is performed on the grid side of the photovoltaic system to adjust the three-phase imbalance of the photovoltaic system.

[0173] In one embodiment, when the computer program is executed by the processor, the following steps are also implemented: according to the three-phase current on the grid side, the current compensation mode required on the grid side of the photovoltaic system is determined; when the required current compensation mode is upward compensation, the minimum phase current in the inverter three-phase current is adjusted to compensate for the minimum phase current on the grid side; when the required current compensation mode is downward compensation, the maximum phase current in the inverter three-phase current is adjusted to compensate for the minimum large phase current on the grid side.

[0174] In one embodiment, when the computer program is executed by the processor, the following steps are also implemented: obtaining the average value of each phase current in the three-phase current on the grid side; determining a first difference between the maximum phase current and the average value of the three-phase current on the grid side, and a second difference between the average value and the minimum phase current of the three-phase current on the grid side; when the first difference is greater than the second difference, determining that the current compensation mode required by the photovoltaic inverter is upward compensation; when the first difference is less than or equal to the second difference, determining that the current compensation mode required by the photovoltaic inverter is downward compensation.

[0175] In one embodiment, when the computer program is executed by the processor, the following steps are also implemented: obtaining the cumulative power generation of each phase of the photovoltaic inverter; selecting the phase with the smallest cumulative power generation as the adjustment phase to change the phase sequence of the photovoltaic inverter.

[0176] In one embodiment, when the computer program is executed by the processor, the following steps are also implemented: determining the three-phase imbalance of the photovoltaic system based on the three-phase electrical parameters of the grid side of the photovoltaic system; when the three-phase imbalance is greater than a preset threshold, determining that the photovoltaic system meets the three-phase imbalance adjustment conditions.

[0177] In one embodiment, a computer program product is provided, comprising a computer program, which, when executed by a processor, implements the following steps:

[0178] When the photovoltaic system meets the three-phase unbalanced regulation conditions, the grid-side three-phase current of the photovoltaic system and the inverter three-phase current of the photovoltaic inverter in the photovoltaic system are obtained; the photovoltaic inverter working mode is determined according to the current operating status parameters of the photovoltaic inverter; when the photovoltaic inverter is in the busy working mode, the photovoltaic inverter is compensated for the phase current according to the grid-side three-phase current, the inverter three-phase current, and the preset margin parameters of the photovoltaic inverter to adjust the three-phase imbalance of the photovoltaic system.

[0179] In one embodiment, when the computer program is executed by the processor, the following steps are also implemented: determining the current regulation mode required for the photovoltaic inverter based on the three-phase current on the grid side, the inverter three-phase current, and the preset margin parameters of the photovoltaic inverter; when the required current regulation mode is the current increase margin regulation mode, compensating for the minimum phase current in the inverter three-phase current; when the required current regulation mode is the current reduction margin regulation mode, compensating for the maximum phase current in the inverter three-phase current.

[0180] In one embodiment, when the computer program is executed by the processor, the following steps are also implemented: obtaining the current sum of the minimum phase current in the inverter three-phase current and the preset current boost threshold; when the minimum phase current in the three-phase current on the grid side is greater than the current sum and less than the preset maximum allowable current, determining that the required current regulation mode is the current boost margin regulation mode.

[0181] In one embodiment, when the computer program is executed by the processor, the following steps are also implemented: obtaining the current difference between the maximum phase current in the inverter three-phase current and a preset current reduction threshold; when the preset minimum allowable current is greater than the maximum phase current in the three-phase current on the grid side and less than the current difference, determining that the required current regulation mode is the current reduction margin regulation mode.

[0182] In one embodiment, when the computer program is executed by the processor, the following steps are also implemented: when it is determined that the three-phase unbalance adjustment capability of the photovoltaic inverter is exceeded based on the three-phase current on the grid side, the inverter three-phase current, and the preset margin parameters of the photovoltaic inverter, the three-phase unbalance adjustment device of the photovoltaic system is controlled to adjust the three-phase imbalance of the photovoltaic system.

[0183] In one embodiment, when the computer program is executed by the processor, the following steps are also implemented: predicting the future required phase sequence of the photovoltaic inverter based on the historical cumulative power generation and historical phase sequence of each phase of the photovoltaic inverter; and controlling the photovoltaic inverter to adjust the phase sequence according to the future required phase sequence.

[0184] In one embodiment, when the computer program is executed by the processor, the following steps are also implemented: when the photovoltaic inverter is in an idle working mode, phase current compensation is performed on the grid side of the photovoltaic system to adjust the three-phase imbalance of the photovoltaic system.

[0185] In one embodiment, when the computer program is executed by the processor, the following steps are also implemented: according to the three-phase current on the grid side, the current compensation mode required on the grid side of the photovoltaic system is determined; when the required current compensation mode is upward compensation, the minimum phase current in the inverter three-phase current is adjusted to compensate for the minimum phase current on the grid side; when the required current compensation mode is downward compensation, the maximum phase current in the inverter three-phase current is adjusted to compensate for the minimum large phase current on the grid side.

[0186] In one embodiment, when the computer program is executed by the processor, the following steps are also implemented: obtaining the average value of each phase current in the three-phase current on the grid side; determining a first difference between the maximum phase current and the average value of the three-phase current on the grid side, and a second difference between the average value and the minimum phase current of the three-phase current on the grid side; when the first difference is greater than the second difference, determining that the current compensation mode required by the photovoltaic inverter is upward compensation; when the first difference is less than or equal to the second difference, determining that the current compensation mode required by the photovoltaic inverter is downward compensation.

[0187] In one embodiment, when the computer program is executed by the processor, the following steps are also implemented: obtaining the cumulative power generation of each phase of the photovoltaic inverter; selecting the phase with the smallest cumulative power generation as the adjustment phase to change the phase sequence of the photovoltaic inverter.

[0188] In one embodiment, when the computer program is executed by the processor, the following steps are also implemented: determining the three-phase imbalance of the photovoltaic system based on the three-phase electrical parameters of the grid side of the photovoltaic system; when the three-phase imbalance is greater than a preset threshold, determining that the photovoltaic system meets the three-phase imbalance adjustment conditions.

[0189] The above-mentioned computer device, storage medium and computer program product, when the photovoltaic inverter of the photovoltaic system is in the power transmission state, that is, the direct current generated by the photovoltaic components of the photovoltaic system is converted into alternating current and transmitted to the alternating current grid to power the power consumption equipment, if it is judged that the photovoltaic system meets the three-phase imbalance adjustment conditions, not only the three-phase current on the grid side can be obtained, but also the inverter three-phase current when the photovoltaic inverter is transmitting power. Then, the current operating state parameters of the photovoltaic inverter are further combined to analyze and determine the working mode of the photovoltaic inverter. Finally, when the photovoltaic inverter is in the busy working mode, the phase current compensation of the photovoltaic inverter is performed in combination with the preset margin parameters of the photovoltaic inverter, and the obtained three-phase current on the grid side and the inverter three-phase current, so as to adjust the three-phase imbalance of the photovoltaic system. Through this scheme, when the photovoltaic inverter is in power transmission operation, the phase current compensation of the photovoltaic inverter can be performed in combination with the preset margin parameters of the photovoltaic inverter and the three-phase current on the grid side and the inverter three-phase current. Thereby, the three-phase imbalance adjustment of the photovoltaic system is realized through the photovoltaic inverter while maintaining the stable power transmission operation of the photovoltaic inverter.

[0190] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A photovoltaic system operation method, characterized in that: include: When the photovoltaic system meets the three-phase unbalanced regulation condition, obtaining the grid-side three-phase current of the photovoltaic system and the inverter three-phase current of the photovoltaic inverter in the photovoltaic system; Determining the operating mode of the photovoltaic inverter according to the current operating state parameters of the photovoltaic inverter; When the photovoltaic inverter is in a busy working mode, phase current compensation is performed on the photovoltaic inverter according to the three-phase current on the grid side, the inverter three-phase current, and a preset margin parameter of the photovoltaic inverter to adjust the three-phase imbalance of the photovoltaic system.

2. The photovoltaic system operation method according to claim 1, characterized in that: The phase current compensation of the photovoltaic inverter is performed according to the three-phase current of the grid side, the inverter three-phase current, and the preset margin parameter of the photovoltaic inverter, including: Determining a current regulation mode required by the photovoltaic inverter according to the grid-side three-phase current, the inverter three-phase current, and a preset margin parameter of the photovoltaic inverter; When the required current regulation mode is the current boost margin regulation mode, compensating for the minimum phase current in the inverter three-phase current; When the required current regulation mode is the current reduction margin regulation mode, the maximum phase current in the inverter three-phase current is compensated.

3. The photovoltaic system operation method according to claim 2, characterized in that: The preset margin parameters include a preset current boost threshold and a preset maximum allowable current; The determining the current regulation mode required by the photovoltaic inverter according to the grid-side three-phase current, the inverter three-phase current, and the preset margin parameter of the photovoltaic inverter includes: Obtaining a current sum of a minimum phase current in the inverter three-phase current and the preset current boost threshold; When the minimum phase current among the three-phase currents on the grid side is greater than the current sum and less than the preset maximum allowable current, it is determined that the required current regulation mode is the current boost margin regulation mode.

4. The photovoltaic system operation method according to claim 2 or 3, characterized in that: The preset margin parameters include a preset current reduction threshold and a preset minimum allowable current; The determining the current regulation mode required by the photovoltaic inverter according to the grid-side three-phase current, the inverter three-phase current, and the preset margin parameter of the photovoltaic inverter includes: Obtaining a current difference between a maximum phase current in the inverter three-phase current and the preset current reduction threshold; When the preset minimum allowable current is greater than the maximum phase current of the three-phase current on the grid side and less than the current difference, it is determined that the required current regulation mode is the current reduction margin regulation mode.

5. The photovoltaic system operation method according to any one of claims 1 to 4, characterized in that: When the photovoltaic inverter is in a busy working mode, the method further includes: When it is determined that the three-phase unbalance adjustment capability of the photovoltaic inverter is exceeded according to the three-phase current on the grid side, the inverter three-phase current, and the preset margin parameters of the photovoltaic inverter, the three-phase unbalance adjustment device of the photovoltaic system is controlled to adjust the three-phase unbalance of the photovoltaic system.

6. The photovoltaic system operation method according to any one of claims 1 to 4, characterized in that: When the photovoltaic inverter is in a busy working mode, the method further includes: Predicting the future required phase sequence of the photovoltaic inverter according to the historical accumulated power generation of each phase and the historical phase sequence of the photovoltaic inverter; The photovoltaic inverter is controlled to adjust the phase sequence according to the future required phase sequence.

7. The photovoltaic system operation method according to any one of claims 1 to 6, characterized in that: After determining the working mode of the photovoltaic inverter according to the current operating state parameters of the photovoltaic inverter, the method further includes: When the photovoltaic inverter is in an idle working mode, phase current compensation is performed on the grid side of the photovoltaic system to adjust the three-phase imbalance of the photovoltaic system.

8. The photovoltaic system operation method according to claim 7, characterized in that: The performing phase current compensation on the grid side of the photovoltaic system comprises: Determining a current compensation mode required for the grid side of the photovoltaic system according to the three-phase current on the grid side; When the required current compensation mode is upward compensation, adjusting the minimum phase current in the inverter three-phase current to compensate for the minimum phase current on the grid side; When the required current compensation mode is downward compensation, the maximum phase current in the inverter three-phase current is adjusted to compensate for the minimum large phase current on the grid side.

9. The photovoltaic system operation method according to claim 8, characterized in that: The step of determining the current compensation mode required by the photovoltaic inverter according to the three-phase current on the grid side includes: Obtaining an average value of each phase current in the three-phase current on the grid side; Determine a first difference between the maximum phase current of the three-phase current on the grid side and the average value, and a second difference between the average value and the minimum phase current of the three-phase current on the grid side; When the first difference is greater than the second difference, determining that the current compensation mode required by the photovoltaic inverter is upward compensation; When the first difference is less than or equal to the second difference, it is determined that the current compensation mode required by the photovoltaic inverter is downward compensation.

10. The photovoltaic system operation method according to any one of claims 7 to 9, characterized in that: When the photovoltaic inverter is in an idle working mode, the method further includes: Obtaining the cumulative power generation of each phase of the photovoltaic inverter; The phase with the smallest cumulative power generation is selected as the adjustment phase to change the phase sequence of the photovoltaic inverter.

11. The photovoltaic system operation method according to any one of claims 1 to 10, characterized in that: The photovoltaic system meets the three-phase unbalanced regulation conditions, including: Determining the three-phase imbalance of the photovoltaic system according to the three-phase electrical parameters of the photovoltaic system on the grid side; When the three-phase imbalance degree is greater than a preset threshold, it is determined that the photovoltaic system meets the three-phase imbalance adjustment condition.

12. A photovoltaic system operating device, characterized in that: include: A phase current acquisition module, used to acquire the grid-side three-phase current of the photovoltaic system and the inverter three-phase current of the photovoltaic inverter in the photovoltaic system when the photovoltaic system meets the three-phase unbalanced regulation condition; A working mode determination module, used to determine the working mode of the photovoltaic inverter according to the current operating state parameters of the photovoltaic inverter; The imbalance adjustment module is used to perform phase current compensation on the photovoltaic inverter according to the three-phase current on the grid side, the inverter three-phase current, and the preset margin parameters of the photovoltaic inverter when the photovoltaic inverter is in a busy working mode, so as to adjust the three-phase imbalance of the photovoltaic system.

13. A photovoltaic system, characterized in that: It includes a photovoltaic component, a photovoltaic inverter, an AC power grid and a controller, wherein the photovoltaic inverter is arranged between the photovoltaic component and the AC power grid, the photovoltaic inverter is connected to the controller, and the controller is used to execute the steps of the photovoltaic system operation method described in any one of claims 1-11.

14. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the photovoltaic system operation method according to any one of claims 1 to 11 are implemented.

15. 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 photovoltaic system operation method according to any one of claims 1 to 11 are implemented.

16. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the photovoltaic system operation method according to any one of claims 1 to 11 are implemented.

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