Inverter parallel operation control method and inverter parallel operation system

Abstract

The invention discloses an inverter parallel operation control method and an inverter parallel operation system, the method is applied to parallel operation control equipment in the inverter parallel operation system, and the inverter parallel operation system comprises at least two inverters connected in parallel and the parallel operation control equipment. The method comprises the following steps: determining the total residual capacity based on the residual capacity of the battery of each inverter under the condition that the inverter parallel operation system sets that the battery is preferentially used as an energy source; determining the proportion of the residual capacity of the battery of each inverter in the total residual capacity; and distributing the battery power for the battery of each inverter based on the proportion of each inverter and the total battery power.

Description

Technical Field

[0001] The present application relates to the technical field of inverters, and in particular to an inverter parallel control method and an inverter parallel system. Background Art

[0002] In the related technology, the power of a household energy storage inverter is relatively small, and a parallel box needs to be added for parallel expansion. Therefore, a parallel box is developed to form a parallel system with multiple energy storage inverters to meet market demand. Currently, energy storage products only have a battery control solution for a single unit, and there is no battery control solution for a parallel energy storage inverter system. For a parallel energy storage inverter system, the balanced control of the battery capacity of multiple inverters is a problem that must be solved. Summary of the invention

[0003] In view of this, an embodiment of the present application provides an inverter parallel control method and an inverter parallel system.

[0004] The technical solution of the embodiment of the present application is implemented as follows:

[0005] The embodiment of the present application provides an inverter parallel control method, which is applied to a parallel control device in an inverter parallel system, wherein the inverter parallel system includes at least two parallel inverters and the parallel control device, and the method includes:

[0006] In the case where the inverter parallel system is configured with batteries being preferentially used as energy sources, determining the total remaining capacity based on the remaining capacity of the battery of each inverter;

[0007] Determining the ratio of the remaining capacity of the battery of each inverter to the total remaining capacity;

[0008] Based on the ratio and the total battery power of each inverter, battery power is allocated to the battery of each inverter.

[0009] In the above solution, allocating battery power to the battery of each inverter based on the ratio of each inverter and the total battery power includes:

[0010] The battery power allocated to the battery of each inverter is determined by multiplying the ratio of each inverter by the total battery power.

[0011] In the above scheme, based on the ratio of each inverter and the total battery power, the battery power is allocated to the battery of each inverter, including:

[0012] determining a change in battery power of each inverter based on the total battery power, the current battery power of each inverter, and the ratio of each inverter;

[0013] The battery power allocated to the battery of each inverter is determined based on the current battery power of each inverter and the battery power change.

[0014] In the above scheme, when the battery is charged, the battery power is the charging power, and the total battery power is the battery power setting value.

[0015] In the above solution, when the battery and the grid are discharged simultaneously, the battery power is the discharge power, and the method further includes:

[0016] The total battery power is determined based on the current battery discharge power of each inverter, the current grid output power, the preset excess power and the battery power setting value.

[0017] In the above solution, when the battery is discharged, after allocating battery power to the battery of each inverter, the method further includes:

[0018] If there is an inverter in the inverter parallel system whose battery-allocated discharge power is greater than the rated discharge power, the battery-allocated discharge power of the inverter is adjusted.

[0019] In the above solution, the adjusting the discharge power allocated to the battery of the inverter includes:

[0020] Arrange all inverters from large to small according to the remaining capacity of the battery to obtain the sorting result;

[0021] Starting from the inverter with the largest remaining battery capacity in the sorting result, the portion of the discharge power allocated to the battery that exceeds the rated discharge power is allocated to the battery of the next inverter in the sorting result in turn, until all inverters in the sorting result complete the discharge power allocation, wherein the discharge power of the battery of each inverter shall not be greater than the rated discharge power.

[0022] An embodiment of the present application also provides a parallel control device, including: a processor and a memory for storing a computer program that can be run on the processor, wherein the processor is used to execute the steps in the above method when running the computer program.

[0023] An embodiment of the present application also provides an inverter parallel system, including: at least two parallel inverters and a parallel control device.

[0024] An embodiment of the present application further provides a computer storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above method are implemented.

[0025] An embodiment of the present application also provides a computer program product, including a computer program, which implements the steps of the above method when executed by a processor.

[0026] The embodiment of the present application is applied to a parallel control device in an inverter parallel system, wherein the inverter parallel system includes at least two parallel inverters and a parallel control device, wherein the parallel control device is configured to: determine the total remaining capacity based on the remaining capacity of the battery of each inverter when the inverter parallel system sets the battery as the energy source first. Determine the ratio of the remaining capacity of the battery of each inverter to the total remaining capacity, and allocate battery power to the battery of each inverter based on the ratio of the remaining capacity of the battery of each inverter to the total remaining capacity and the total battery power. The embodiment of the present application can realize intelligent power scheduling of the inverter parallel system, and the battery power distribution of the inverter is distributed according to the battery SOC ratio, which can ensure the battery SOC balance of each inverter and improve the stability of the inverter parallel system. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a structural schematic diagram of an inverter parallel system provided by an embodiment of the present invention;

[0028] Figure 2 is a structural schematic diagram of another inverter parallel system provided by an embodiment of the present invention;

[0029] Figure 3 It is a schematic diagram of an implementation flow of a signal processing method provided by an embodiment of the present invention;

[0030] Figure 4 is a flow chart of another inverter parallel control method provided by an embodiment of the present invention;

[0031] Figure 5 is a flow chart of another inverter parallel control method provided by an embodiment of the present invention;

[0032] Figure 6 It is a structural schematic diagram of a parallel control device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] The energy storage converter is the core component that realizes the bidirectional flow of electric energy between the energy storage system and the power grid. It is used to control the charging and discharging process of the battery and perform AC / DC conversion. It can convert the DC power of the battery into AC power and transmit it to the power grid or use it for AC loads; it can also rectify the AC power of the power grid into DC power to charge the battery.

[0035] Since household energy storage inverters have low power per unit, they need to add a parallel box (parallel control device) for parallel expansion. Therefore, a parallel box is developed to form a parallel system with multiple energy storage inverters to meet market demand. Figure 1 As shown, Figure 1 This is a structural diagram of an inverter parallel system provided by an embodiment of the present invention. The inverter parallel system includes at least two parallel inverters and a parallel control device, and the parallel control device controls the entire inverter parallel system. The power of all inverters will pass through the parallel control device, and the parallel control device will collect and record data, calculate, and issue control instructions, so that the control is precise.

[0036] Figure 2 is a structural schematic diagram of another inverter parallel system provided by an embodiment of the present invention, Figure 2 It consists of two energy storage inverters (ESS) and one parallel control device. The energy storage inverter includes photovoltaic (PV), battery (BAT) and inverter (INV). INV is connected to the parallel control device, and the parallel control device is connected to the grid (GRAD) and load (LOAD).

[0037] For energy storage inverters, there are external control mode and self-generation and self-use mode. The external control mode is the working mode used for certification. The certification requirements of different countries are different. According to the certification requirements, some settings are changed through the parallel control device to flexibly control the grid-connected machine to meet different certification requirements. For example, whether the battery is discharged first, or the grid is discharged first, how much discharge power, etc. For example, the external control working principles include:

[0038] 1. When the grid is set to be the priority and the active power setting value is positive, take +12kW as an example, it means that the inverter power needs to output +12kW of power to the load. If the load power exceeds 12kW, the grid will supplement energy to the load. If the load power is less than 12kW, the excess inverter power will be fed back to the grid. If the PV energy exceeds 12kW, the excess energy will be charged to the battery; if the PV energy is less than 12kW, the battery will be discharged to supplement it to meet the output target of 12kW inverter power.

[0039] 2. When the grid is set to priority and the active power setting value is negative, taking -12kW as an example, it means that the inverter needs to absorb 12kW of power from the grid side to charge the battery, and the load is powered by the grid by default.

[0040] 3. When the battery priority is set to a positive value, take +6kW as an example, it means that the battery discharge power is 6kW at this time. If the 6kW discharge power can meet the load requirements, the excess energy will be fed back to the grid; if the 6kW discharge power cannot meet the load requirements, it will be supplemented by PV discharge, and if it is still not enough, it will be supplemented by the grid.

[0041] 4. When the battery is set to be given priority and the battery power setting value is negative, take -6kW as an example, which means that the battery charging power is 6kW at this time. At this time, PV energy is used to charge the battery first. If it is less than 6kW, the grid will supplement the charging. If there is any surplus after PV energy charges the battery at 6kW, the surplus energy will be supplied to the load. If the energy is not enough to supply the load, it will be supplemented by the grid. If there is any surplus energy after PV energy charges the battery at 6kW and supplies the load at the same time, it will be fed back to the grid.

[0042] The self-generation and self-use mode is a mode that maximizes the economic benefits of customers. In this working mode, when PV energy is sufficient, PV energy is supplied to the load first, and the excess energy is used to charge the battery. Before the battery is fully charged, it is necessary to ensure that no energy is fed into the grid, and no energy is absorbed by the grid. After the battery is fully charged, if there is any surplus PV energy after supplying it to the load, it will be fed back to the grid. When PV energy is insufficient, the battery needs to be discharged and supplied to the load together with PV until the PV energy is exhausted and the battery is prohibited from being discharged. After the battery and PV energy are exhausted, the grid supplies energy to the load. In general, PV energy will be used to power the load first, and as little electricity as possible will be purchased from the grid.

[0043] In the single-machine external control mode, when set to grid priority, the energy storage inverter controls the inverter power to be equal to the "active power setting value" to achieve the control purpose of external control and grid priority; when set to battery priority, the energy storage inverter controls the battery power to be equal to the "battery charge and discharge power setting value" to achieve the control purpose of external control and battery priority.

[0044] The external control scheme of the inverter parallel system follows the single machine external control scheme. When the grid is given priority, the inverter power of the parallel system is controlled. When the battery is given priority, the battery power of the parallel system is controlled.

[0045] In view of the external control scheme of the inverter parallel system, the embodiment of the present invention provides an inverter parallel control method, referring to Figure 3 , Figure 3 1 is a schematic diagram of an implementation flow of a signal processing method provided by an embodiment of the present invention. The method is applied to a parallel control device in an inverter parallel system. The signal processing method includes:

[0046] S301, when the inverter parallel system is configured to preferentially use the battery as an energy source, determine the total remaining capacity based on the remaining capacity of the battery of each inverter.

[0047] The inverter includes a battery, and the battery may be composed of a plurality of battery packs.

[0048] When the inverter parallel system is set to battery priority mode, there are two situations, battery discharge and battery charging. In battery priority mode, the battery energy is used to supply the load during discharge. When charging, the photovoltaic or grid energy is used to supply the battery.

[0049] The battery is preferentially used as an energy source, including the battery being used as an energy source to preferentially supply power to a load (discharging), and the battery being used as an energy source to be charged (replenishing energy).

[0050] Determine the remaining capacity of the battery of each inverter in the inverter parallel system. The remaining capacity here refers to the state of charge (SoC), which indicates the current state of charge or charge and discharge status of the battery. It is an indicator used to quantify the remaining capacity of the battery. Its value is defined as the ratio of the current remaining capacity of the battery to the total capacity, usually expressed as a percentage, and its value range is between 0 and 1.

[0051] In one embodiment, the total remaining capacity may be the sum of the remaining capacities of the batteries of each inverter.

[0052] S302, determining the ratio of the remaining capacity of the battery of each inverter to the total remaining capacity.

[0053] For example, calculate the ratio of the remaining capacity of the battery of each inverter to the total remaining capacity. Assume that the inverter parallel system includes 2 inverters in total, the battery SOC of inverter 1 is 28%, and the battery SOC of inverter 2 is 45%. Then the corresponding ratio of the battery of inverter 1 is 28 / (28+45)≈38%, and the corresponding ratio of the battery of inverter 2 is 45 / (28+45)≈62%.

[0054] S303: Allocate battery power to the battery of each inverter based on the ratio of each inverter and the total battery power.

[0055] In order to ensure that the battery SOC of each inverter is balanced, the power allocation scheme of this embodiment is allocated according to the SOC ratio. For example, a larger SOC is allocated more power, and a smaller SOC is allocated less power.

[0056] In one embodiment, allocating battery power to the battery of each inverter based on the ratio of each inverter and the total battery power includes:

[0057] The battery power allocated to the battery of each inverter is determined by multiplying the ratio of each inverter by the total battery power.

[0058] For example, according to the above example, the SOC ratio of inverter 1 is 38%, and the battery power allocated to inverter 1 is total battery power × 38%. Assuming the total battery power is 16KW, the battery power allocated to the battery of inverter 1 is 16kW / (28+45)*28=6.13kW.

[0059] The embodiment of the present application is applied to a parallel control device in an inverter parallel system, wherein the inverter parallel system includes at least two parallel inverters and a parallel control device, wherein the parallel control device is configured to: determine the total remaining capacity based on the remaining capacity of the battery of each inverter when the inverter parallel system sets the battery as the energy source first. Determine the ratio of the remaining capacity of the battery of each inverter to the total remaining capacity, and allocate battery power to the battery of each inverter based on the ratio of the remaining capacity of the battery of each inverter to the total remaining capacity and the total battery power. The embodiment of the present application can realize intelligent power scheduling of the inverter parallel system, and the battery power distribution of the inverter is distributed according to the battery SOC ratio, which can ensure the battery SOC balance of each inverter and improve the stability of the inverter parallel system.

[0060] In one embodiment, when the battery is charged, the battery power is the charging power, and the total battery power is the battery power setting value.

[0061] While the battery is charging, the total battery power is equal to the battery power setting value.

[0062] If the battery provides energy to the load and there is no other energy source to power the load, the total battery power is also equal to the battery power setting value.

[0063] In one embodiment, when the battery and the grid are discharged simultaneously, the battery power is the discharge power, and the method further includes:

[0064] The total battery power is determined based on the current battery discharge power of each inverter, the current grid output power, the preset excess power and the battery power setting value.

[0065] For example, total battery power = MAX((total battery power + grid power - excess power setting value), battery power setting value).

[0066] When the load draws power from the grid and the battery at the same time, when (grid power - excess power)>0, it means that the power currently drawn by the load from the grid exceeds the "excess power". In this case, the battery power needs to be increased to reduce the grid power to below the excess power to meet the over-demand prevention function.

[0067] In one embodiment, allocating battery power to the battery of each inverter based on the ratio of each inverter and the total battery power includes:

[0068] determining a change in battery power of each inverter based on the total battery power, the current battery power of each inverter, and the ratio of each inverter;

[0069] The battery power allocated to the battery of each inverter is determined based on the current battery power of each inverter and the battery power change.

[0070] For example, the battery power change of each inverter = (total battery power - current battery power) * SOC[i] * (~force charge flag [i])) / Sum (SOC[i] * (~force charge flag [i])).

[0071] The battery power of each inverter = the battery power of each inverter + the change in the battery power of each inverter.

[0072] Among them, the strong charge flag [i] represents the strong charge flag of the battery of the i-th inverter. If the flag is true, it means that strong charge is currently required and the inverter does not participate in the power distribution during discharge.

[0073] refer to Figure 4 , Figure 4 It is a flow chart of another inverter parallel control method provided by an embodiment of the present invention.

[0074] First, determine whether it is in external control mode, and if so, determine whether it is grid priority mode or battery priority mode.

[0075] In the grid priority mode, the total inverter power = active power setting value, and the inverter power of each inverter = total inverter power / number of online inverters.

[0076] In battery priority mode, when charging: total battery power = battery power setting value; when discharging, total battery power = MAX ((total battery power + grid power - excess power setting value), battery power setting value). The battery power of each inverter = the battery power of each inverter + the battery power change of each inverter.

[0077] In one embodiment, when the battery is discharged, after allocating battery power to the battery of each inverter, the method further includes:

[0078] If there is an inverter in the inverter parallel system whose battery-allocated discharge power is greater than the rated discharge power, the battery-allocated discharge power of the inverter is adjusted.

[0079] In one example, in external control mode, the battery discharges 16Kw first, inverter 1PV: 15kW, inverter 2PV: 12kW. The inverter parallel system does not turn on anti-reverse flow and anti-over-demand, the battery can be charged and discharged, no-load, and each inverter is equipped with 2 battery packs (each battery pack has a full discharge power of 4kW).

[0080] Assume that the energy associated with the inverter parallel system is displayed as PV: 10460w; grid: 24029w; battery: 13569w; load: 0w; balancing value: 0. The debugging platform shows that the battery power of inverter 1 is 6135w, SOC: 28%; the battery power of inverter 2 is 7992w, SOC: 45%. Neither inverter triggers derating, but the battery power of inverter 1 is not fully discharged, resulting in the battery discharge requirement of 16kW not being met.

[0081] The SOC of BAT1 is 28%, and the SOC of BAT2 is 45%. Therefore, the discharge power of BAT1 and BAT2 is distributed according to the SOC ratio, which is:

[0082] BAT1 = 16kW / (28+45)*28 = 6.13kW, the actual discharge power is 6.135kW, which meets the design;

[0083] BAT2=16kW / (28+45)*45=9.86kW;

[0084] Since each inverter is equipped with 2 battery packs, and the rated discharge power of a single battery pack is 4KW, the maximum battery discharge power of each inverter is 8KW. Therefore, the discharge power of BAT2 is limited to 8kW, resulting in the total battery discharge power of the parallel system = 6.135kW + 8kW = 14.135kW, which does not meet the set 16kW requirement.

[0085] To address this problem, after distributing the battery discharge power according to SOC during discharge, if there is an inverter in the inverter parallel system whose battery discharge power is greater than the rated discharge power, the portion of the discharge power allocated to the battery of the inverter that exceeds the rated discharge power is distributed to the battery of the inverter in the inverter parallel system whose discharge power is less than the rated discharge power. For example, the portion of BAT2 exceeding 8kW is distributed to BAT1.

[0086] In one example, the adjusting the discharge power of the battery of the inverter includes:

[0087] Arrange all inverters from large to small according to the remaining capacity of the battery to obtain the sorting result;

[0088] Starting from the inverter with the largest remaining battery capacity in the sorting result, the portion of the discharge power allocated to the battery that exceeds the rated discharge power is allocated to the battery of the next inverter in the sorting result in turn, until all inverters in the sorting result complete the discharge power allocation, wherein the discharge power of the battery of each inverter shall not be greater than the rated discharge power.

[0089] After distributing the battery discharge power according to SOC during discharge, the online inverters are sorted according to the size of SOC, such as Figure 5 As shown, Figure 5 1 is a flow chart of another inverter parallel control method provided by an embodiment of the present invention. Assume that the online inverters are sorted, and the SOCs are ranked from large to small: ESS[i], ESS[j], ESS[z], ESS[y].

[0090] First, fine-tune the power of ESS[i] to determine whether the battery power of ESS[i] is greater than the rated battery power*the number of battery packs of ESS[i]. If so, the fine-tuned power is ΔPbat[i]=battery power of ESS[i]-rated battery power*the number of battery packs of ESS[i]. After fine-tuning, the battery power of ESS[i]=rated battery power*the number of battery packs of ESS[i]. The fine-tuned power is allocated to ESS[j], and the battery power of ESS[j]+=ΔPbat[i].

[0091] If the battery power of ESS[i] is not greater than the rated battery power*the number of battery packs of ESS[i], then determine whether the battery power of ESS[j] is greater than the rated battery power*the number of battery packs of ESS[j]. If it is greater, the fine-tuned power is ΔPbat[j]=battery power of ESS[j]-rated battery power*the number of battery packs of ESS[j]. After fine-tuning, the battery power of ESS[j]=rated battery power*the number of battery packs of ESS[j]. The fine-tuned power is allocated to the battery power of ESS[z]+=ΔPbat[j].

[0092] If the battery power of ESS[j] is not greater than the rated battery power*the number of battery packs of ESS[j], then determine whether the battery power of ESS[z] is greater than the rated battery power*the number of battery packs of ESS[z]. If it is greater, then the fine-tuned power ΔPbat[z]=battery power of ESS[z]-rated battery power*the number of battery packs of ESS[z]. After fine-tuning, the battery power of ESS[z]=rated battery power*the number of battery packs of ESS[z]. The fine-tuned power is allocated to the battery power of ESS[y]+=ΔPbat[z].

[0093] If the battery power of ESS[z] is not greater than the rated battery power*the number of battery packs of ESS[z], then determine whether the battery power of ESS[y] is greater than the rated battery power*the number of battery packs of ESS[y]. If it is greater, since ESS[y] is the last inverter in the sorting result, the battery power of ESS[y] = rated battery power*the number of battery packs of ESS[y].

[0094] This embodiment proposes an effective solution to the problem of abnormal battery power allocated to inverter batteries in the inverter parallel system when battery priority is given, so that the battery power allocated to the batteries of all inverters does not exceed their rated power, thereby improving system stability.

[0095] In one example, when setting the battery charge and discharge power, the rated power of the single battery pack is used for limiting.

[0096] The charging and discharging power of each inverter shall not be greater than the rated power of a single battery pack*the number of batteries.

[0097] In order to implement the method of the embodiment of the present application, the embodiment of the present application also provides an inverter parallel control device, which corresponds to the above-mentioned inverter parallel control method, and each step in the above-mentioned inverter parallel control method embodiment is also fully applicable to the present inverter parallel control device embodiment.

[0098] The device includes:

[0099] A first determination module is used to determine the total remaining capacity based on the remaining capacity of the battery of each inverter when the inverter parallel system sets the battery as the energy source first;

[0100] A second determination module is used to determine the ratio of the remaining capacity of the battery of each inverter to the total remaining capacity;

[0101] A power allocation module is used to allocate battery power to the battery of each inverter based on the ratio of each inverter and the total battery power.

[0102] In one embodiment, the power distribution module is specifically used for:

[0103] The battery power allocated to the battery of each inverter is determined by multiplying the ratio of each inverter by the total battery power.

[0104] In one embodiment, the power distribution module is specifically used for:

[0105] determining a change in battery power of each inverter based on the total battery power, the current battery power of each inverter, and the ratio of each inverter;

[0106] The battery power allocated to the battery of each inverter is determined based on the current battery power of each inverter and the battery power change.

[0107] In one embodiment, when the battery is charged, the battery power is the charging power, and the total battery power is the battery power setting value.

[0108] In one embodiment, when the battery and the grid are discharged simultaneously, the battery power is the discharge power, and the device further includes:

[0109] The third determination module is used to determine the total battery power based on the current battery discharge power of each inverter, the current grid output power, the preset excess power and the battery power setting value.

[0110] In one embodiment, when the battery is discharged, the device further comprises:

[0111] The fine-tuning module is used to adjust the discharge power allocated to the battery of the inverter if there is an inverter in the inverter parallel system whose battery discharge power is greater than the rated discharge power.

[0112] In one embodiment, the fine-tuning module is specifically used for:

[0113] Arrange all inverters from large to small according to the remaining capacity of the battery to obtain the sorting result;

[0114] Starting from the inverter with the largest remaining battery capacity in the sorting result, the portion of the battery discharge power that exceeds the rated discharge power is allocated to the battery of the next inverter in the sorting result in turn, until all inverters in the sorting result complete the discharge power allocation, wherein the discharge power of the battery of each inverter shall not be greater than the rated discharge power.

[0115] In actual application, the first determination module, the second determination module and other modules can be implemented by a processor in the parallel control device. Of course, the processor needs to run the computer program in the memory to realize its function.

[0116] It should be noted that: the inverter parallel control device provided in the above embodiment only uses the division of the above program modules as an example when performing inverter parallel control and module training. In actual applications, the above processing can be assigned to different program modules as needed, that is, the internal structure of the device is divided into different program modules to complete all or part of the processing described above. In addition, the inverter parallel control device and the inverter parallel control method embodiment provided in the above embodiment belong to the same concept, and the specific implementation process is detailed in the method embodiment, which will not be repeated here.

[0117] Based on the hardware implementation of the above program modules, and in order to implement the method of the embodiment of the present application, the embodiment of the present application also provides a parallel control device. Figure 6 Schematic diagram of the hardware structure of the parallel control device of the present application embodiment. Figure 6 As shown, the parallel control device includes:

[0118] Communication interface 601, capable of exchanging information with other devices such as network devices;

[0119] The processor 602 is connected to the communication interface 601 to implement information exchange with other devices and is used to execute the method provided by one or more technical solutions when running a computer program. The computer program is stored in the memory 603.

[0120] Of course, in actual application, the various components in the parallel control device are coupled together through the bus system 604. It can be understood that the bus system 604 is used to realize the connection and communication between these components. In addition to the data bus, the bus system also includes a power bus, a control bus and a status signal bus. However, for the sake of clarity, Figure 6 Various buses are labeled as bus system 604 .

[0121] The memory 603 in the embodiment of the present application is used to store various types of data to support the operation of the computer device. Examples of such data include: any computer program used to operate on the parallel control device.

[0122] It can be understood that the memory 603 can be a volatile memory or a non-volatile memory, and can also include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a magnetic random access memory (FRAM), a flash memory, a magnetic surface memory, an optical disk, or a compact disc read-only memory (CD-ROM); the magnetic surface memory can be a disk memory or a tape memory. The volatile memory can be a random access memory (RAM), which is used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static random access memory (SRAM), synchronous static random access memory (SSRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), direct memory bus random access memory (DRRAM). The memory described in the embodiments of the present application is intended to include but is not limited to these and any other suitable types of memory.

[0123] The method disclosed in the above embodiment of the present application can be applied to a processor or implemented by a processor. The processor may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by an integrated logic circuit of hardware in the processor or an instruction in the form of software. The above processor may be a general-purpose processor, a DSP, or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. The processor can implement or execute the various methods, steps and logic block diagrams disclosed in the embodiments of the present application. The general-purpose processor may be a microprocessor or any conventional processor, etc. In combination with the steps of the method disclosed in the embodiment of the present application, it can be directly embodied as a hardware decoding processor to execute, or it can be executed by a combination of hardware and software modules in the decoding processor. The software module can be located in a storage medium, which is located in a memory, and the processor reads the program in the memory and completes the steps of the above method in combination with its hardware.

[0124] Optionally, when the processor 602 executes the program, it implements the corresponding processes implemented by the computer device in each method of the embodiments of the present application, which will not be described in detail here for the sake of brevity.

[0125] In an exemplary embodiment, the present application also provides a storage medium, namely a computer storage medium, specifically a computer-readable storage medium, for example, including a first memory storing a computer program, and the computer program can be executed by a processor of a computer device to complete the steps of the aforementioned method. The computer-readable storage medium can be a memory such as FRAM, ROM, PROM, EPROM, EEPROM, Flash Memory, magnetic surface storage, optical disk, or CD-ROM.

[0126] In the several embodiments provided in the present application, it should be understood that the disclosed devices, computer equipment and methods can be implemented in other ways. The device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as: multiple units or components can be combined, or can be integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the components shown or discussed can be through some interfaces, and the indirect coupling or communication connection of the devices or units can be electrical, mechanical or other forms.

[0127] The units described above as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units; some or all of the units may be selected according to actual needs to achieve the purpose of the scheme of this embodiment.

[0128] In addition, all functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may be a separate unit, or two or more units may be integrated into one unit; the above-mentioned integrated units may be implemented in the form of hardware or in the form of hardware plus software functional units.

[0129] A person of ordinary skill in the art can understand that: all or part of the steps of implementing the above-mentioned method embodiment can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium, which, when executed, executes the steps of the above-mentioned method embodiment; and the aforementioned storage medium includes: various media that can store program codes, such as mobile storage devices, ROM, RAM, disks or optical disks.

[0130] Alternatively, if the above-mentioned integrated unit of the present application is implemented in the form of a software function module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the embodiment of the present application can be essentially or partly embodied in the form of a software product that contributes to the relevant technology. The computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as mobile storage devices, ROM, RAM, magnetic disks or optical disks.

[0131] In an exemplary embodiment, the embodiment of the present application further provides a computer program product, including a computer program, which can be executed by the processor 602 of the parallel control device to complete the steps described in the inverter parallel control method of the embodiment of the present application.

[0132] It should be noted that: "first", "second", etc. are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0133] In addition, the technical solutions described in the embodiments of the present application can be combined arbitrarily without conflict.

[0134] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. An inverter parallel control method, applied to a parallel control device in an inverter parallel system, wherein the inverter parallel system comprises at least two parallel inverters and the parallel control device, characterized in that: The method comprises: In the case where the inverter parallel system is configured with batteries being preferentially used as energy sources, determining the total remaining capacity based on the remaining capacity of the battery of each inverter; Determining the ratio of the remaining capacity of the battery of each inverter to the total remaining capacity; Based on the ratio and the total battery power of each inverter, battery power is allocated to the battery of each inverter.

2. The method according to claim 1, characterized in that: The allocating battery power to the battery of each inverter based on the ratio of each inverter and the total battery power includes: The battery power allocated to the battery of each inverter is determined by multiplying the ratio of each inverter by the total battery power.

3. The method according to claim 1, characterized in that: The allocating battery power to the battery of each inverter based on the ratio of each inverter and the total battery power includes: determining a change in battery power of each inverter based on the total battery power, the current battery power of each inverter, and the ratio of each inverter; The battery power allocated to the battery of each inverter is determined based on the current battery power of each inverter and the battery power change.

4. The method according to claim 1, characterized in that: When the battery is charged, the battery power is the charging power, and the total battery power is the battery power setting value.

5. The method according to claim 1, characterized in that: In the case where the battery and the grid are discharged simultaneously, the battery power is the discharge power, and the method further includes: The total battery power is determined based on the current battery discharge power of each inverter, the current grid output power, the preset excess power and the battery power setting value.

6. The method according to claim 1, characterized in that: In the case where the battery is discharged, after allocating battery power to the battery of each inverter, the method further comprises: If there is an inverter in the inverter parallel system whose battery-allocated discharge power is greater than the rated discharge power, the battery-allocated discharge power of the inverter is adjusted.

7. The method according to claim 6, characterized in that: The step of adjusting the discharge power allocated to the battery of the inverter comprises: Arrange all inverters from large to small according to the remaining capacity of the battery to obtain the sorting result; Starting from the inverter with the largest remaining battery capacity in the sorting result, the portion of the discharge power allocated to the battery that exceeds the rated discharge power is allocated to the battery of the next inverter in the sorting result in turn, until all inverters in the sorting result complete the discharge power allocation, wherein the discharge power of the battery of each inverter shall not be greater than the rated discharge power.

8. An inverter parallel control device, characterized in that: include: A first determination module is used to determine the total remaining capacity based on the remaining capacity of the battery of each inverter when the inverter parallel system sets the battery as the energy source first; A second determination module is used to determine the ratio of the remaining capacity of the battery of each inverter to the total remaining capacity; A power allocation module is used to allocate battery power to the battery of each inverter based on the ratio of each inverter and the total battery power.

9. A parallel control device, characterized in that: include: A processor and a memory for storing a computer program that can be run on the processor, wherein the processor, when running the computer program, executes the steps of the method according to any one of claims 1 to 7.

10. An inverter parallel system, characterized in that: include: At least two parallel inverters and a parallel control device, wherein the parallel control device is used to execute the steps of the method according to any one of claims 1 to 7.

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