Alternating-current-coupled power supply system, and photovoltaic-storage inverter and control method therefor

Abstract

Disclosed in the present application are an alternating-current-coupled power supply system, and a photovoltaic-storage inverter and a control method therefor. The alternating-current-coupled power supply system comprises a first inverter and a second inverter, wherein a switching apparatus is provided between an alternating-current side of the first inverter and an alternating-current side of the second inverter. The control method comprises: acquiring the state of a power grid, and in response to the state of the power grid being abnormal, controlling a first inverter and a second inverter to disconnect from the grid; and acquiring a generation power of a second photovoltaic array and an alternating-current load power and direct-current load power of the second inverter, and in response to the generation power of the second photovoltaic array being less than the sum of the alternating-current load power and the direct-current load power, controlling a switching apparatus to close. The present application can control a switching apparatus between a first inverter and a second inverter to close when a power grid is abnormal, such that an output power of the first inverter is used to supplement a required power on an alternating-current side and direct-current side of the second inverter, thereby improving the energy utilization rate of the alternating-current-coupled power supply system.

Description

AC coupling power supply system, light storage inverter and control method thereof

[0001] The present application claims priority to the Chinese patent application No. 2024110874405, filed on August 8, 2024, entitled "AC coupling power supply system, light storage inverter and control method thereof", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the field of photovoltaic power generation technology, in particular to an AC coupling power supply system, a light storage inverter and a control method thereof. BACKGROUND

[0003] With the continuous expansion of photovoltaic + energy storage applications, photovoltaic inverters and light storage inverters, as one of the core devices of photovoltaic power generation and energy storage systems, play an increasingly important role in optimizing power allocation and achieving system stability. Photovoltaic inverters can convert variable direct current generated by photovoltaic solar panels into alternating current for power grids or electrical appliances. Light storage inverters can complete the bidirectional conversion of direct current and alternating current, can convert alternating current into direct current for storage, and can control the charging and discharging process of the battery. SUMMARY

[0004] In order to solve the problems of the prior art, the purpose of the present application is to provide an AC coupling power supply system, a light storage inverter and a control method thereof, which can control the closing of the switching device between the first inverter and the second inverter when the power grid is abnormal, so as to realize the output power of the first photovoltaic array to supplement the power demand of the load and the energy storage module, and improve the energy utilization rate of the AC coupling power supply system.

[0005] To achieve the above purpose, the technical solution adopted by the present application is as follows:

[0006] In a first aspect, the present application provides a control method of a light storage inverter. The light storage inverter control method is applied to inverter control in an AC coupling power supply system. The AC coupling power supply system includes a first inverter and a second inverter. The direct current side of the first inverter is used to connect a first photovoltaic array, and the alternating current side of the first inverter is used to connect a power grid. The direct current side of the second inverter is used to connect a second photovoltaic array and an energy storage module, and the alternating current side of the second inverter is used to connect the power grid and a load. A switching device is arranged between the alternating current side of the first inverter and the alternating current side of the second inverter. The control method includes the following steps:

[0007] Obtaining a power grid state, and in response to an abnormal power grid state, controlling the first inverter and the second inverter to be off-grid.

[0008] The power generation of the second photovoltaic array, the AC load power of the second inverter and the DC load power are acquired, and the switch device is controlled to be closed in response to the power generation of the second photovoltaic array being less than the sum of the AC load power and the DC load power.

[0009] The control method of the light storage inverter, by controlling the first inverter and the second inverter to be off-grid when the grid state is abnormal, acquiring the power generation of the second photovoltaic array, the AC load power of the second inverter and the DC load power, and further controlling the switch device to be closed in the case that the power generation of the second photovoltaic array is less than the sum of the AC load power and the DC load power, so that the AC side of the first inverter and the AC side of the second inverter are connected, to realize the first photovoltaic array output power to make up the power demand of the load and the energy storage module, and improve the energy utilization rate of the AC coupling power supply system.

[0010] In a second aspect, the application provides a light storage inverter applied to an AC coupling power supply system, the AC coupling power supply system comprising a photovoltaic inverter and a light storage inverter, the DC side of the photovoltaic inverter being used to connect a first photovoltaic array, and the AC side of the photovoltaic inverter being used to connect a grid; the DC side of the light storage inverter being used to connect a second photovoltaic array and an energy storage module, the AC side of the light storage inverter being used to connect the grid and a load, and the AC side of the light storage inverter and the AC side of the photovoltaic inverter being provided with a switch device, and the light storage inverter further comprising a control module, the control module being used to realize the light storage inverter control method of any one of the above.

[0011] The AC side of the light storage inverter and the AC side of the photovoltaic inverter are provided with a switch device, and the light storage inverter comprises a control module, the control module being used to control the photovoltaic inverter and the light storage inverter to be off-grid when the grid state is abnormal, acquire the power generation of the second photovoltaic array, the AC load power of the light storage inverter and the DC load power, and further control the switch device to be closed in the case that the power generation of the second photovoltaic array is less than the sum of the AC load power and the DC load power, so that the AC side of the photovoltaic inverter and the AC side of the light storage inverter are connected, to realize the first photovoltaic array output power to make up the power demand of the load and the energy storage module, and improve the energy utilization rate of the AC coupling power supply system.

[0012] In a third aspect, the application provides an AC coupling power supply system, comprising a photovoltaic inverter and a photovoltaic storage inverter; a DC side of the photovoltaic inverter is configured to be connected to a first photovoltaic array, and an AC side of the photovoltaic inverter is configured to be connected to a power grid through a first switch; a DC side of the photovoltaic storage inverter is configured to be connected to a second photovoltaic array and an energy storage module, an AC side of the photovoltaic storage inverter is configured to be connected to a load, and the AC side of the photovoltaic storage inverter is further configured to be connected to the power grid through a second switch; a switch device is arranged between the AC side of the photovoltaic storage inverter and the AC side of the photovoltaic inverter; and the photovoltaic storage inverter further comprises a control module configured to implement the control method of the photovoltaic storage inverter of the first aspect.

[0013] In a fourth aspect, the application provides a control device, which comprises:

[0014] a processing module configured to acquire the state of the power grid, and control the first inverter and the second inverter to be off-grid in response to an abnormal state of the power grid; acquire the power generated by the second photovoltaic array, and the AC load power and the DC load power of the second inverter, and control the switch device to be closed in response to the power generated by the second photovoltaic array being less than the sum of the AC load power and the DC load power.

[0015] In a fifth aspect, the application provides a control module, comprising a processor and a memory connected to the processor in communication;

[0016] the memory stores computer execution instructions;

[0017] the processor executes the computer execution instructions stored in the memory to implement the control method of the photovoltaic storage inverter of the first aspect.

[0018] In a sixth aspect, the application provides a computer readable storage medium, which stores computer execution instructions, and the computer execution instructions are configured to implement the control method of the photovoltaic storage inverter of the first aspect when executed by a processor.

[0019] In a seventh aspect, the application provides a computer program product, comprising a computer program configured to implement the control method of the photovoltaic storage inverter of the first aspect when executed by a processor.

[0020] In an eighth aspect, the application provides a computer program, comprising: the computer program is configured to implement the control method of the photovoltaic storage inverter of the first aspect when executed by a processor.

[0021] The alternating current coupling power supply system, the light storage inverter and the control method thereof provided in the application, the alternating current coupling power supply system comprises a light storage inverter and a photovoltaic inverter, a switching device is arranged between the alternating current side of the light storage inverter and the alternating current side of the photovoltaic inverter, the light storage inverter comprises a control module, the control module is used for controlling the photovoltaic inverter and the light storage inverter to be off-grid when the grid state is abnormal, acquiring the power generation power of a second photovoltaic array, the alternating current load power of the light storage inverter and the direct current load power, and further controlling the switching device to be closed in the case that the power generation power of the second photovoltaic array is less than the sum of the alternating current load power and the direct current load power, so that the alternating current side of the photovoltaic inverter and the alternating current side of the light storage inverter are connected, to realize the power compensation of the direct current side and the alternating current side of the second inverter by the output power of the first inverter, and improve the energy utilization rate of the alternating current coupling power supply system. BRIEF DESCRIPTION OF DRAWINGS

[0022] The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate embodiments consistent with the present application and, together with the description, further serve to explain the principles of the application.

[0023] Fig. 1 is a system block diagram of a photovoltaic system and a photovoltaic energy storage system mixed installation in the related art according to the present application;

[0024] Fig. 2 is an application scenario diagram of a control method of a light storage inverter according to the present application;

[0025] Fig. 3 is a first flowchart of a control method of a light storage inverter according to the present application;

[0026] Fig. 4 is a second flowchart of a control method of a light storage inverter according to the present application;

[0027] Fig. 5 is a third flowchart of a control method of a light storage inverter according to the present application;

[0028] Fig. 6 is a judgment flowchart of a control method of a light storage inverter according to the present application;

[0029] Fig. 7 is a schematic diagram of an alternating current coupling power supply system according to the present application.

[0030] Through the above-mentioned drawings, the specific embodiments of the present application have been shown, and will be described in more detail hereinafter. These drawings and textual descriptions are not intended to limit the scope of the concept of the present application by any means, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0031] The application will be described in detail below with reference to specific embodiments shown in the drawings, but these embodiments do not limit the application, and the structural, method, or functional changes made by those of ordinary skill in the art based on these embodiments are included in the protection scope of the application.

[0032] Under the situation of gradually increasing penetration of new energy, many families are equipped with both pure photovoltaic inverters and photovoltaic storage inverters. Since the technology of photovoltaic storage inverters (referred to as photovoltaic storage inverters) lags behind that of photovoltaic grid-connected inverters (referred to as photovoltaic inverters), in the installation scenario of photovoltaic storage inverters, there may be a photovoltaic inverter with a large power level, and the installation of the photovoltaic storage inverter is only considered for off-grid operation to provide uninterrupted power supply to the family when the power grid is abnormal. Due to the presence of the photovoltaic inverter, the photovoltaic capacity that the photovoltaic storage inverter can install is extremely limited, and there is no problem of energy utilization rate when the power grid is normally operated. When the power grid is abnormal, the photovoltaic inverter will stop working, at which time the photovoltaic power generation capacity provided by the photovoltaic inverter will not work. The photovoltaic storage inverter operates off-grid to provide energy to the standby load, and when the light condition is relatively poor, the time that the photovoltaic storage inverter can support off-grid operation is limited, and the pure photovoltaic inverter is in a shutdown state, which cannot be used as a source of energy supply, greatly reducing the energy utilization rate of the entire system.

[0033] The system block diagram of the mixed installation of the photovoltaic system 110 and the photovoltaic energy storage system 120 in the related art is shown in FIG. 1. Among them, the photovoltaic system 110 contains a photovoltaic grid-connected inverter 111 and a part of photovoltaic panels 112, and the normal operation of the photovoltaic system 110 depends on the existence of the power grid 140, and when the power grid is abnormal, the photovoltaic system 110 will be disconnected from the power grid 140 and stop generating electricity. The photovoltaic energy storage system 120 includes a photovoltaic energy storage inverter 121 and the photovoltaic panels 122 and energy storage batteries 123 equipped, and the photovoltaic energy storage system 120 can provide alternating current for the load 130, and the main purpose of the photovoltaic energy storage system 120 is to achieve high economic benefits according to its own energy management system, and has the off-grid power storage function. When the power grid 140 is abnormal, the photovoltaic energy storage system 120 can realize off-grid operation to continue to provide alternating current for the load 130, and realize the uninterruptible power supply function.

[0034] As shown in FIG. 1, the photovoltaic system 110 and the photovoltaic energy storage system 120 in the related art are independent of each other and do not affect each other, that is, when the power grid 140 is normal, the two are connected in parallel at the AC grid-connected port, and each realizes its own function, and when the power grid 140 is abnormal, the photovoltaic system 110 stops working, and the photovoltaic energy storage system 120 operates off-grid. The disadvantage of this mode is that when the power grid 140 is abnormal, the photovoltaic system 110 stops working, resulting in that the photovoltaic panels 112 configured by the photovoltaic system 110 cannot realize their power generation value, and the economic benefit decreases; at the same time, if the photovoltaic panels 122 configured by the photovoltaic energy storage system 120 are limited, the photovoltaic energy storage system 120 also has the problem of being unable to supply power or insufficient power supply for the load 130 when operating off-grid.

[0035] The purpose of the present application is to provide a technical solution to solve the problem that when the power grid 140 is abnormal, the photovoltaic system 110 stops working, and the photovoltaic energy storage system 120 operates off-grid, the photovoltaic system 110 stops working, resulting in that the photovoltaic panels 112 configured by the photovoltaic system 110 cannot realize their power generation value, and the economic benefit decreases; at the same time, when the photovoltaic panels 122 configured by the photovoltaic energy storage system 120 are limited, the photovoltaic energy storage system 120 has the problem of being unable to meet the power demand of the load 130 when operating off-grid.

[0036] The application scenario of the control method of the photovoltaic energy storage inverter provided by the embodiment of the present application is shown in FIG. 2. The AC coupling power supply system 210 includes a first inverter 211 and a first switch 211a for controlling the first inverter 211 and operating off-grid, a second inverter 212 and a second switch 212a for controlling the second inverter 212 and operating off-grid, the DC side of the first inverter 211 is used to connect a first photovoltaic array 213, and the AC side of the first inverter 211 is connected with the power grid 140 through the first switch 211a; the DC side of the second inverter 212 is used to connect a second photovoltaic array 214 and an energy storage module 215, and the AC side of the second inverter 212 is connected with the power grid 140 through the second switch 212a, and the AC side of the second inverter 212 can also be used to connect the load 130; and the AC side of the first inverter 211 and the AC side of the second inverter 212 are provided with a switching device 216.

[0037] Specifically, the first inverter 211 can be, but is not limited to, a photovoltaic inverter, which can convert variable direct current generated by a photovoltaic solar panel into alternating current for the power grid 140 or electrical appliances. The second inverter 212 can be, but is not limited to, a photovoltaic storage inverter, which can complete bidirectional conversion of direct current and alternating current, can convert alternating current into direct current for storage, and can control the charging and discharging process of the energy storage module 215. The first photovoltaic array 213 and the second photovoltaic array 214 each include a plurality of photovoltaic components or photovoltaic panels, and are used to convert solar energy into electrical energy. The energy storage module 215 can be, but is not limited to, a battery, a capacitor, etc., and can be used to store electrical energy for release to the load 130 when needed to power the load 130. The load 130 can be, but is not limited to, industrial equipment, household appliances, communication equipment, agricultural equipment, energy storage equipment, etc. The switching device 216 is an electrical control device, which is provided between the alternating current side of the first inverter 211 and the alternating current side of the second inverter 212, and by controlling the switching device 216, the connection and disconnection of the alternating current sides of the first inverter 211 and the second inverter 212 can be controlled. Further, EMS communication (energy management system communication) can also be performed between the first inverter 211 and the second inverter 212. In this way, through the switching device 216 and EMS communication, the switching and distribution of alternating current energy between the two inverters can be realized. The switching device 216 can include a relay or other controllable switch; preferably, in an embodiment, the switching device 216 includes two series-connected alternating current relays.

[0038] It should be noted that in the description of the present application, the terms "first", "second", etc. are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. The meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0039] As shown in FIG. 3, the control method of the photovoltaic storage inverter provided by an embodiment of the present application is described by taking the inverter control in the AC coupling power supply system 210 shown in FIG. 2 as an example. The control method of the photovoltaic storage inverter specifically includes the following steps:

[0040] In step S301, the state of the power grid 140 is acquired, and in response to an abnormal state of the power grid 140, the first inverter 211 and the second inverter 212 are controlled to be off-grid.

[0041] The power grid 140 refers to the overall power system composed of substations and transmission lines of various voltages, and the power grid 140 state refers to the state of abnormal operation of the power system in operation. The power grid 140 state abnormality includes voltage or frequency fluctuations, equipment failures, line interruptions, and the like.

[0042] If the power grid 140 state is normal, the first inverter 211 and the second inverter 212 operate normally.

[0043] If the power grid 140 state is abnormal, the first inverter 211 and the second inverter 212 are controlled to be off-grid, that is, the first switch 211a between the first inverter 211 and the power grid 140 is disconnected, and the second switch 212a between the second inverter 212 and the power grid 140 is disconnected, to avoid the power grid 140 state abnormality from causing a power consumption accident.

[0044] In step S302, the power generation power of the second photovoltaic array 214, the AC load power of the second inverter 212, and the DC load power are obtained, and the switch device 216 is controlled to be closed in response to the power generation power of the second photovoltaic array 214 being less than the sum of the AC load power and the DC load power.

[0045] The power generation power of the second photovoltaic array 214 refers to the power generated by the photovoltaic array when converting solar energy into electrical energy. The power generation power of the second photovoltaic array 214 can be obtained by measuring the output power of the second photovoltaic array 214 using a power meter, or by monitoring the current and voltage of the second photovoltaic array 214 to calculate the power generation power.

[0046] The AC load power of the second inverter 212 refers to the power consumed by the AC side of the second inverter 212. The AC load power includes the power consumed by the load 130 through the AC side output of the second inverter 212, and the amount of power consumed by the load 130 depends on the types and quantities of the load 130 and the demand for electrical energy. In some embodiments, the AC load power also includes the power consumed by other AC loads connected to the AC side of the second inverter 212, such as an AC load connected to the AC side of the second inverter 212 for converting AC power to DC power to power other DC electrical appliances, and the like.

[0047] The DC load power of the second inverter 212 refers to the power consumed by the DC side of the second inverter 212. The DC load power includes the power consumed by the energy storage module 215 through the DC side output of the second inverter 212 for electrical energy conversion, and in some embodiments, the DC load power also includes the power consumed by other DC loads connected to the DC side of the second inverter 212, such as a DC load connected to the DC side of the second inverter 212 for charging new energy vehicles, and the like.

[0048] If the power generated by the second photovoltaic array 214 is less than the sum of the AC load power and the DC load power, i.e., the power generated by the second photovoltaic array 214 is insufficient to support the required power on the AC side of the second inverter 212 and the required power on the DC side of the second inverter 212, the control switch device 216 is closed at this time, so that the AC side of the first inverter 211 and the AC side of the second inverter 212 are connected, and the power output through the AC side of the first inverter 211 is used to make up the required power on the AC side of the second inverter 212 and the required power on the DC side of the second inverter 212, so as to utilize the power generation capacity of the first photovoltaic array 214 and improve the utilization rate thereof.

[0049] According to the above description, the control method of the photovoltaic energy storage inverter of the embodiment, by opening the first switch 211a and the second switch 212a when the grid 140 is in an abnormal state, the first inverter 211 and the second inverter 212 are controlled to be off-grid, and further, the power generated by the second photovoltaic array 214, the AC load power of the second inverter 212 and the DC load power are obtained, and in response to the power generated by the second photovoltaic array 214 being less than the sum of the AC load power and the DC load power, the control switch device 216 is closed, so that the AC side of the first inverter 211 and the AC side of the second inverter 212 are connected, and the power output through the AC side of the first inverter 211 is used to make up the required power on the DC side and the AC side of the second inverter 212, so as to improve the energy utilization rate of the AC coupling power supply system 210, thereby improving the economic benefit and the power stability.

[0050] In one embodiment, based on the embodiment of FIG. 3, the control method of the photovoltaic energy storage inverter further comprises: in response to the power generated by the second photovoltaic array 214 being greater than or equal to the sum of the AC load power and the DC load power, controlling the control switch device 216 to be opened.

[0051] The power generated by the second photovoltaic array 214 is greater than or equal to the sum of the AC load power and the DC load power, i.e., the power generated by the second photovoltaic array 214 is sufficient to support the power demand of the load 130, and there may be excess power that can be converted and stored in the energy storage module 215. In this case, the power output through the AC side of the first inverter 211 is not needed, and the control switch device 216 is controlled to be opened, so as to prevent the excess power generation, and avoid the damage of devices due to the fact that the AC coupling power supply system 210 cannot accommodate the excess power.

[0052] In one embodiment, based on the embodiment of FIG. 3, as shown in FIG. 4, the control method of the photovoltaic energy storage inverter further comprises:

[0053] In step S401, the difference power is obtained, which is the difference between the sum of the AC load power and the DC load power and the power generated by the second photovoltaic array 214.

[0054] The difference power represents a difference between the sum of the AC load power and the DC load power of the second inverter 212 and the power generated by the second photovoltaic array 214, and the difference power includes the power required to be supplemented on the DC side of the second inverter 212 and the AC side of the second inverter 212. Specifically, in the case where the power generated by the second photovoltaic array 214 is less than the sum of the AC load power and the DC load power, the difference power is greater than zero, that is, the power required by the AC side and the DC side of the second inverter 212 at this time is not satisfied and needs to be supplemented additionally.

[0055] It can be understood that in the case where the power generated by the second photovoltaic array 214 is not less than the sum of the AC load power and the DC load power, the control switch device 216 is disconnected at this time.

[0056] Step S402, in response to the difference power being less than or equal to the rated power of the first inverter 211, controlling the first photovoltaic array 213 and the second photovoltaic array 214 to output power to jointly bear the AC load power and / or the DC load power.

[0057] If the difference power is less than or equal to the rated power of the first inverter 211, that is, the output power of the first inverter 211 can supplement the difference power. Therefore, the switch device 216 is closed, and the first photovoltaic array 213 is controlled to output power to share the AC load power and / or the DC load power.

[0058] In the embodiment, by obtaining the difference power between the sum of the AC load power and the DC load power of the second inverter 212 and the power generated by the second photovoltaic array 214, and further controlling the first photovoltaic array 213 and the second photovoltaic array 214 to output power to jointly bear the AC load power and / or the DC load power when the difference power is less than or equal to the rated power of the first inverter 211, more accurate control of the inverter is realized, and the flexibility and reliability of the control are improved, and the stable operation of the AC coupling power supply system 210 is improved.

[0059] In one embodiment, based on the above embodiment, when controlling the first photovoltaic array to output power, in response to the difference power being less than or equal to the rated power of the first inverter 211, the output power of the first inverter 211 to the second inverter 212 is adjusted, and the output power of the first inverter 211 satisfies the following relationship:

[0060] The output power of the first inverter 211 is equal to the difference between the sum of the AC load power and the DC load power and the power generated by the second photovoltaic array 214.

[0061] It can be understood that at this time, the output power of the first inverter 211 is equal to the difference power, which just makes up for the demand of the AC load power and the DC load power, and at this time, the control energy storage module 215 does not output electric energy, thereby avoiding waste of electric energy.

[0062] In the embodiment, when the difference power is less than or equal to the rated power of the first inverter 211, the output power of the first inverter 211 to the second inverter 212 is adjusted, so that the output power of the first inverter 211 is equal to the difference between the sum of the AC load power and the DC load power and the power generated by the second photovoltaic array 214, and the control energy storage module 215 does not output electric energy, thereby avoiding waste of electric energy and improving the energy utilization rate of the AC coupling power supply system 210.

[0063] In one embodiment, based on any one of the above embodiments, the control method further comprises obtaining the remaining electric quantity of the energy storage module 215, and in response to the remaining electric quantity being greater than a first preset electric quantity threshold and the difference power being greater than the rated power of the first inverter 211, controlling the first photovoltaic array 213, the second photovoltaic array 214 and the energy storage module 215 to output power to jointly bear the AC load power and / or the DC load power.

[0064] The remaining electric quantity of the energy storage module 215 refers to the remaining available electric energy in the energy storage module 215. The first preset electric quantity threshold is used to determine whether the remaining electric quantity of the energy storage module 215 meets the required electric quantity.

[0065] If the remaining electric quantity is greater than the first preset electric quantity threshold and the difference power is greater than the rated power of the first inverter 211, it indicates that the remaining electric quantity of the energy storage module 215 still has a margin, and the output power of the first inverter 211 is insufficient to make up for the difference power. In this case, the first photovoltaic array 213, the second photovoltaic array 214 and the energy storage module 215 are controlled to output power to jointly bear the AC load power and / or the DC load power, that is, the energy storage module 215 can output electric energy to support the required power of the second inverter 212 load in this case, so as to avoid the problem that the second inverter 212 load cannot be supported to operate.

[0066] In the embodiment, by obtaining the remaining electric quantity of the energy storage module 215, when the remaining electric quantity is greater than the first preset electric quantity threshold and the difference power is greater than the rated power of the first inverter 211, the first photovoltaic array 213, the second photovoltaic array 214 and the energy storage module 215 are controlled to output power to jointly bear the AC load power and / or the DC load power, thereby realizing more accurate control of the inverter and improving the stability and reliability of the operation of the AC coupling power supply system 210.

[0067] In one embodiment, based on the above embodiment, in response to the difference power being greater than the rated power of the first inverter 211, the first inverter 211 is controlled to operate according to the rated power.

[0068] If the difference power is greater than the rated power of the first inverter 211, it indicates that the power required to be supplemented exceeds the output power of the first inverter 211. In this case, the first inverter 211 is controlled to operate according to the rated power, so that the output power of the first inverter 211 is equal to the rated power of the first inverter 211, thereby optimizing the output efficiency of the first inverter 211 and improving the operating efficiency of the AC coupling power supply system 210.

[0069] In one embodiment, based on any one of the above embodiments, as shown in FIG. 5, the control method of the optical storage inverter further includes:

[0070] Step S501, in response to the remaining power being less than or equal to the second preset power threshold, obtaining the maximum DC load power, the maximum DC load power including the maximum standby power of the energy storage module 215, and the second preset power threshold being greater than or equal to the first preset power threshold.

[0071] Step S502, obtaining the maximum difference power, the maximum difference power being the difference between the sum of the AC load power and the maximum DC load power and the power generation of the second photovoltaic array 214.

[0072] Step S503, in response to the maximum difference power being less than or equal to the rated power of the first inverter 211, adjusting the output power of the first inverter 211 to the second inverter 212, the output power of the first inverter 211 satisfying the following relationship:

[0073] The output power of the first inverter 211 is equal to the difference between the sum of the AC load power and the maximum DC load power and the power generation of the second photovoltaic array 214.

[0074] Wherein, if the remaining power is less than or equal to the second preset power threshold, the energy storage module 215 is charged, which ensures that the energy storage module 215 has sufficient storage capacity to accommodate the power generated by the first photovoltaic array 213 and the second photovoltaic array 214, and avoids damage to the energy storage module 215. The second preset power threshold is greater than or equal to the first preset power threshold, which can avoid the remaining power of the energy storage module 215 being too low. The maximum DC load power is the load consumption power of the second inverter 212 DC side under the maximum standby power of the energy storage module 215; the maximum standby power of the energy storage module 215 represents the maximum input power of the energy storage module 215 when it is on standby, and the energy storage module 215 can store power quickly under the maximum standby power.

[0075] Specifically, if the remaining power is less than or equal to the second preset power threshold, the maximum DC load power is obtained, the maximum DC load power including the maximum standby power of the energy storage module 215, and the energy storage module 215 uses the maximum standby power for power conversion to supplement the power.

[0076] The maximum difference power is obtained between the sum of the maximum DC load power and the AC load power and the power generation power of the second photovoltaic array 214, and the maximum difference power can indicate whether the power generation power of the second photovoltaic array 214 meets the required power of the DC side and the AC side of the second inverter 212 in the case that the energy storage module 215 uses the maximum standby power to supplement the power.

[0077] If the maximum difference power is greater than zero, it indicates that the power generation power of the second photovoltaic array 214 cannot meet the required power of the DC side and the AC side of the second inverter 212. Further, if the maximum difference power is less than or equal to the rated power of the first inverter 211, it indicates that the maximum difference power can be supplemented by the output power of the first inverter 211, and the output power of the first inverter 211 is adjusted to the second inverter 212, and the output power of the first inverter 211 meets the following relationship:

[0078] The output power of the first inverter 211 is equal to the difference between the sum of the AC load power and the maximum DC load power and the power generation power of the second photovoltaic array 214.

[0079] That is, the output power of the first inverter 211 is equal to the maximum difference power, which just supplements the maximum difference power, prevents the power generation from being excessive, and avoids device damage due to the fact that the AC coupling power supply system 210 cannot consume the excessive power.

[0080] In the embodiment, by obtaining the maximum DC load power when the remaining power is less than or equal to the second preset power threshold, the energy storage module 215 uses the maximum standby power to standby power; further, the maximum difference power is obtained, and in the case that the maximum difference power is less than or equal to the rated power of the first inverter 211, the output power of the first inverter 211 to the second inverter 212 is adjusted, and the output power of the first inverter 211 is equal to the maximum difference power, which realizes that the required power of the DC side and the AC side of the second inverter 212 is just supplemented by adjusting the output power of the first inverter 211, thereby preventing the power generation from being excessive and avoiding device damage due to the fact that the AC coupling power supply system 210 cannot consume the excessive power.

[0081] Further, in an embodiment, based on the above embodiment, in response to the maximum difference power being greater than the rated power of the first inverter 211, the first inverter 211 is controlled to operate according to the rated power.

[0082] If the maximum difference power is greater than the rated power of the first inverter 211, it indicates that the power to be supplemented exceeds the output power of the first inverter 211, in which case the first inverter 211 is controlled to operate in accordance with the rated power, so that the output power of the first inverter 211 is equal to the rated power of the first inverter 211, thereby optimizing the output efficiency of the first inverter 211, further improving the fine management capability of the AC coupling power supply system 210, and improving the operation efficiency and energy utilization rate of the AC coupling power supply system 210.

[0083] In order to more specifically illustrate the application of the control method of the optical storage inverter of the embodiments of the present application, in a specific embodiment, as shown in FIG. 6, a judgment flow chart of the control method of the optical storage inverter is also provided, which specifically includes the following steps:

[0084] Step S601, the state of the power grid 140 is acquired, and it is judged whether the state of the power grid 140 is abnormal; if the judgment result is yes, step S602 is executed; if the judgment result is no, step S603 is executed.

[0085] Step S602, the first inverter 211 and the second inverter 212 are normally operated.

[0086] Step S603, the first inverter 211 and the second inverter 212 are controlled to be off-grid, and the power generated by the second photovoltaic array 214, the AC load power of the second inverter 212 and the DC load power are acquired.

[0087] Step S604, it is judged whether the power generated by the second photovoltaic array 214 is less than the sum of the AC load power of the second inverter 212 and the DC load power; if the judgment result is yes, step S606 is executed; if the judgment result is no, step S605 is executed.

[0088] Step S605, the switch device 216 is controlled to be opened.

[0089] Step S606, the switch device 216 is controlled to be closed, and the remaining power of the energy storage module 215 is acquired.

[0090] Step S607, it is judged whether the remaining power is less than or equal to the second preset power threshold; if the judgment result is yes, step S608 is executed; if the judgment result is no, step S612 is executed.

[0091] Step S608, the maximum DC load power is acquired, and the maximum difference power is acquired.

[0092] Step S609, it is judged whether the maximum difference power is less than or equal to the rated power of the first inverter 211; if the judgment result is yes, step S610 is executed; if the judgment result is no, step S611 is executed.

[0093] Step S610, adjusting the output power of the first inverter 211 to be the maximum difference power.

[0094] Step S611, adjusting the output power of the first inverter 211 to be the rated power of the first inverter 211.

[0095] Step S612, obtaining the difference power.

[0096] Step S613, judging whether the remaining power is greater than the first preset power threshold and whether the difference power is greater than the rated power of the first inverter 211; if the result of the judgment is yes, executing step S614; if the result of the judgment is no, executing step S615.

[0097] Step S614, controlling the first photovoltaic array 213, the second photovoltaic array 214 and the energy storage module 215 to output power to jointly bear the AC load power and / or the DC load power.

[0098] Step S615, controlling the first photovoltaic array 213 and the second photovoltaic array 214 to output power to jointly bear the AC load power and / or the DC load power.

[0099] It should be understood that, although each step in the flowchart involved in the above embodiments is shown in sequence according to the arrow, these steps are not necessarily executed in the order indicated by the arrow. Unless otherwise specified herein, the execution of these steps is not strictly limited in sequence, and these steps can be executed in other orders. Moreover, at least part of the steps in the flowchart involved in the above embodiments can include multiple steps or stages, which 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 sequential, but can be executed in rotation or alternation with at least part of other steps or stages.

[0100] Based on the same inventive concept, the embodiments of the present application also provide a photovoltaic energy storage inverter for implementing the control method of the photovoltaic energy storage inverter as described above. The implementation scheme for solving the problem provided by the photovoltaic energy storage inverter is similar to the implementation scheme described in the above method, so the specific limitations in the photovoltaic energy storage inverter embodiments provided below can refer to the limitations of the control method of the photovoltaic energy storage inverter described above, which will not be repeated here.

[0101] In one embodiment, as shown in FIG. 7, a light storage inverter 712 is provided for an AC coupled power supply system 710, the AC coupled power supply system 710 including a first inverter and a second inverter, wherein the first inverter is a photovoltaic inverter 711, and the second inverter is the light storage inverter 712. The DC side of the photovoltaic inverter 711 is configured to connect a first photovoltaic array 713, and the AC side of the photovoltaic inverter 711 is configured to connect a power grid 140; the DC side of the light storage inverter 712 is configured to connect a second photovoltaic array 714 and an energy storage module 715, and the AC side of the light storage inverter 712 is configured to connect the power grid 140 and a load 130, and a switching device 716 is arranged between the DC side of the light storage inverter 712 and the DC side of the photovoltaic inverter 711, and the light storage inverter 712 further includes a control module 712a configured to implement the control method of the light storage inverter in any of the above embodiments.

[0102] In one embodiment, an AC coupled power supply system 710 is provided, the AC coupled power supply system 710 including a photovoltaic inverter 711 and a light storage inverter 712; the DC side of the photovoltaic inverter 711 is configured to connect a first photovoltaic array 713, and the AC side of the photovoltaic inverter 711 is configured to connect a power grid 140 through a first switch 711a; the DC side of the light storage inverter 712 is configured to connect a second photovoltaic array 714 and an energy storage module 715, and the AC side of the light storage inverter 712 is configured to connect a load 130, and the AC side of the light storage inverter 712 is further configured to connect the power grid 140 through a second switch 712a, and a switching device 716 is arranged between the AC side of the light storage inverter 712 and the AC side of the photovoltaic inverter 711, and the light storage inverter 712 further includes a control module 712b configured to implement the control method of the light storage inverter in any of the above embodiments.

[0103] In summary, the control method of the light storage inverter, the light storage inverter 712 and the AC coupled power supply system 710 according to the embodiments of the present application, by controlling the photovoltaic inverter 711 and the light storage inverter 712 to be off-grid when the state of the power grid 140 is abnormal, further obtaining the power generation power of the second photovoltaic array 714, the AC load power and the DC load power of the light storage inverter 712, and in response to the power generation power of the second photovoltaic array 714 being less than the sum of the AC load power and the DC load power, controlling the switching device 716 to be closed, so that the AC side of the photovoltaic inverter 711 and the AC side of the light storage inverter 712 are connected, to realize the first photovoltaic array 713 to output power to supplement the power demand of the load 130 and the energy storage module 715, to improve the energy utilization rate of the AC coupled power supply system 710, and to improve the economic benefit and power stability.

[0104] A control device includes a processing module.

[0105] The processing module is configured to acquire a grid state, control the first inverter and the second inverter to be off-grid in response to the grid state being abnormal, acquire power generated by the second photovoltaic array, AC load power of the second inverter, and DC load power, and control the switch device to be closed in response to the power generated by the second photovoltaic array being less than the sum of the AC load power and the DC load power.

[0106] It should be noted that the above device provided by the embodiments of the present application can realize all the method steps achieved by the method embodiments and achieve the same technical effects. Therefore, the same parts and beneficial effects of the method embodiments will not be described in detail.

[0107] A control module comprises a memory and a processor, the memory is configured to store processor-executable instructions, and the processor is configured to run computer programs or instructions to implement the control method of the light-storage inverter provided in any one of the above embodiments.

[0108] The memory is configured to store programs. Specifically, the programs can include program codes, and the program codes include computer operation instructions. The memory can include a high-speed RAM memory and can also include a non-volatile memory such as at least one disk memory.

[0109] The processor can be a central processing unit (CPU) or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present disclosure.

[0110] Optionally, in specific implementation, if the memory and the processor are implemented independently, the memory and the processor can be connected to each other through a bus and complete communication between each other. The bus can be an industry standard architecture (ISA) bus, a peripheral component (PCI) bus, or an extended industry standard architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc.

[0111] Optionally, in specific implementation, if the memory and the processor are integrated on a chip, the memory and the processor can complete communication between each other through an internal interface.

[0112] A non-transitory computer readable storage medium having stored therein computer-executable instructions that, when executed by a processor of a control module, cause the control module to perform the method of controlling a light storage inverter as described above. The non-transitory computer readable storage medium can be any available medium or data storage device that can be accessed by the processor including, but not limited to, a magnetic storage (e.g., floppy disks, hard disks, tape, MO, etc.), optical storage (e.g., CD-ROMs, DVDs, BDs, HVDs, etc.), and semiconductor storage (e.g., ROMs, EPROMs, EEPROMs, NAND FLASH, SSDs, etc.).

[0113] The embodiments of the present application also provide a computer program product, comprising a computer program, wherein the computer program is executed by a processor to implement the method of controlling a light storage inverter provided by any one of the above embodiments.

[0114] The embodiments of the present application also provide a computer program, wherein the computer program is executed by a processor to implement the method of controlling a light storage inverter provided by any one of the above embodiments.

[0115] It should be understood that the various forms of flow shown above can be used to reorder, add, or delete steps. For example, the steps described in the present application can be executed in parallel, sequentially, or in a different order, as long as the desired results of the technical solutions of the present application can be achieved, and the present application is not limited herein.

[0116] The above disclosure is only the preferred embodiments of the present application, and is not intended to limit the scope of the present application. Those skilled in the art can understand that changes, modifications, substitutions, combinations, simplifications, etc. without departing from the spirit and scope of the present application and the appended claims, are equivalent replacements and still belong to the scope of the present application.

[0117] The technical application field of the present application includes, but is not limited to, the field of photovoltaic power generation. As long as the essence of the technical solutions does not deviate from the scope of the technical solutions of the embodiments of the present application, it belongs to the protection scope of the present application.

[0118] Although the preferred embodiments of the present application have been disclosed for illustrative purposes, those skilled in the art will realize that various modifications, additions and substitutions are possible without departing from the scope and spirit of the present application disclosed by the appended claims.

Claims

1. A control method of a light storage inverter, characterized by, The control method of the light storage inverter is applied to inverter control in an AC coupling power supply system, the AC coupling power supply system comprising a first inverter and a second inverter, a DC side of the first inverter being configured to connect a first photovoltaic array, and an AC side of the first inverter being configured to connect a power grid; a DC side of the second inverter being configured to connect a second photovoltaic array and an energy storage module, and an AC side of the second inverter being configured to connect the power grid and a load; a switching device being arranged between the AC side of the first inverter and the AC side of the second inverter; the control method comprising the following steps: obtaining a state of the power grid, and controlling the first inverter and the second inverter to be off-grid in response to an abnormal state of the power grid; obtaining a power generation power of the second photovoltaic array, an AC load power of the second inverter, and a DC load power, and controlling the switching device to be closed in response to the power generation power of the second photovoltaic array being less than a sum of the AC load power and the DC load power.

2. The control method of the optical storage inverter according to claim 1, wherein The control method further comprises: obtaining a difference power, the difference power being a difference between the sum of the AC load power and the DC load power and the power generation power of the second photovoltaic array; controlling the first photovoltaic array and the second photovoltaic array to output power to jointly bear the AC load power and / or the DC load power in response to the difference power being less than or equal to a rated power of the first inverter.

3. The control method of the light storage inverter according to claim 2, wherein in response to the difference power being less than or equal to the rated power of the first inverter, adjusting an output power of the first inverter to the second inverter, the output power of the first inverter satisfying the following relationship: the output power of the first inverter being equal to the difference between the sum of the AC load power and the DC load power and the power generation power of the second photovoltaic array.

4. The control method of the light storage inverter according to any one of claims 1-3, wherein the control method further comprises obtaining a remaining power of the energy storage module, and controlling the first photovoltaic array, the second photovoltaic array, and the energy storage module to output power to jointly bear the AC load power and / or the DC load power in response to the remaining power being greater than a first preset power threshold and the difference power being greater than the rated power of the first inverter.

5. The control method of the light storage inverter according to claim 4, wherein in response to the difference power being greater than the rated power of the first inverter, controlling the first inverter to operate according to the rated power.

6. The control method of the light storage inverter according to any one of claims 1-5, wherein in response to the remaining power being less than or equal to a second preset power threshold, obtaining a maximum DC load power, the maximum DC load power comprising a maximum standby power of the energy storage module, the second preset power threshold being greater than or equal to the first preset power threshold. The maximum difference power is obtained, which is the difference between the sum of the AC load power and the maximum DC load power and the power generation of the second photovoltaic array; In response to the maximum power difference being less than or equal to the rated power of the first inverter, the output power of the first inverter to the second inverter is adjusted, wherein the output power of the first inverter satisfies the following relationship: The output power of the first inverter is equal to the difference between the sum of the AC load power and the maximum DC load power and the power generation of the second photovoltaic array.

7. The control method for a photovoltaic-storage inverter according to claim 6, characterized in that, In response to the maximum power difference being greater than the rated power of the first inverter, the first inverter is controlled to operate according to the rated power.

8. The control method for a photovoltaic-storage inverter according to any one of claims 1-7, characterized in that, In response to the fact that the power generation of the second photovoltaic array is greater than or equal to the sum of the AC load power and the DC load power, the switching device is controlled to open. 9.A light storage inverter applied to an AC coupling power supply system, the AC coupling power supply system comprising a photovoltaic inverter and the light storage inverter, a DC side of the photovoltaic inverter being configured to connect a first photovoltaic array, an AC side of the photovoltaic inverter being configured to connect a power grid;a DC side of the light storage inverter being configured to connect a second photovoltaic array and an energy storage module, an AC side of the light storage inverter being configured to connect the power grid and a load, characterized in that, A switching device is provided between the AC side of the photovoltaic inverter and the AC side of the solar energy storage inverter. The photovoltaic inverter also includes a control module, which is used to implement the control method of the photovoltaic energy storage inverter as described in any one of claims 1 to 8.

10. An AC coupled power supply system, characterized by, The system includes a photovoltaic inverter and a photovoltaic-storage inverter. The DC side of the photovoltaic inverter is used to connect to a first photovoltaic array, and the AC side of the photovoltaic inverter is used to connect to the power grid through a first switch. The DC side of the photovoltaic-storage inverter is used to connect to a second photovoltaic array and an energy storage module. The AC side of the photovoltaic-storage inverter is used for load connection, and the AC side of the photovoltaic-storage inverter is also used to connect to the power grid through a second switch. A switching device is provided between the AC side of the photovoltaic-storage inverter and the AC side of the photovoltaic inverter. The photovoltaic-storage inverter also includes a control module, which is used to implement the control method of the photovoltaic-storage inverter as described in any one of claims 1 to 8.

11. A control device characterized by comprising: include: The processing module is used to acquire the grid status, and in response to an abnormal grid status, control the first inverter and the second inverter to disconnect from the grid; acquire the power generation of the second photovoltaic array, the AC load power and the DC load power of the second inverter, and in response to the power generation of the second photovoltaic array being less than the sum of the AC load power and the DC load power, control the switching device to close.

12. A control module, characterized by include: A processor, and a memory communicatively connected to the processor; The memory stores computer-executed instructions; The processor executes computer execution instructions stored in the memory to implement the control method for the photovoltaic-storage inverter as described in any one of claims 1-8.

13. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the control method for the photovoltaic-storage inverter as described in any one of claims 1-8.

14. A computer program product, characterised in that, Includes a computer program that, when executed by a processor, implements the control method for the photovoltaic-storage inverter according to any one of claims 1-8.

15. A computer program, characterized in that, include: The computer program, which is executed by a processor, implements the control method of the optical storage inverter according to any one of claims 1-8.

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