Three-phase parallel machine system and its power distribution method and device

Abstract

The present application relates to the technical field of energy storage systems, and discloses a three-phase parallel system and its power distribution method and device. By obtaining the initial distribution power of each phase of each energy storage inverter; according to the initial distribution power of each phase of each energy storage inverter, determining the locked phase and the unlocked phase, locking the energy storage inverter and the unlocked energy storage inverter; according to the locked energy storage inverter and the locked phase, determining the missing power of the locked phase of the locked energy storage inverter; according to the initial distribution power of the unlocked phase of the locked energy storage inverter, obtaining the charging margin; according to the initial distribution power of the unlocked phase of the unlocked energy storage inverter, obtaining the discharging margin; according to the missing power, charging margin and discharging margin, obtaining the target distribution power of each phase of each energy storage inverter. Through the overall calculation of the global margin, the problems of inter-phase power rigidity and single-point bottleneck restricting the overall performance of the traditional parallel system are solved, and the load adaptability and operation reliability of the parallel system are significantly improved.

Description

Technical Field

[0001] The present application relates to the technical field of energy storage systems, and in particular to a three-phase parallel system and a power distribution method and device thereof. Background Art

[0002] With the rapid development of the energy storage industry, especially the widespread adoption of home energy storage products, more and more users are beginning to rely on energy storage products to power their loads. Especially in parallel mode, achieving load matching between energy storage inverters and ensuring stable load power supply has become a key technological development.

[0003] Existing technical solutions primarily include three load distribution methods for parallel systems: 1. Sequential loading, where each inverter connects to the load in sequence according to the power system phase sequence, ensuring balanced load distribution; 2. Equal loading, where multiple inverters share the load, evenly distributing power; and 3. Proportional loading based on the state of charge (SOC) of the energy storage units. These three solutions can optimize the discharge of energy storage batteries and the power output of the inverters to a certain extent, improving overall system efficiency. However, when the discharge capacity of the energy storage batteries within a parallel system varies significantly, the system cannot fully match the load, which remains a challenge facing current technology. Summary of the Invention

[0004] The implementation methods of this application mainly solve the technical problem of how to reasonably and comprehensively distribute power to match the load.

[0005] To solve the above technical problems, a technical solution adopted in the embodiment of the present application is: to provide a power distribution method for a three-phase parallel system, wherein the three-phase parallel system includes at least two energy storage inverters, and the method includes: obtaining the initial distribution power of each phase of each energy storage inverter; determining a locked phase and an unlocked phase based on the initial distribution power of each phase of each energy storage inverter; determining a locked energy storage inverter and an unlocked energy storage inverter based on the initial distribution power of each phase of each energy storage inverter and the discharge limit of the energy storage battery corresponding to each energy storage inverter. ; According to the locked energy storage inverter and the locked phase, determine the missing power of the locked phase of the locked energy storage inverter; according to the initial allocation power of the non-locked phase of the locked energy storage inverter, obtain the charging margin; according to the initial allocation power of the non-locked phase of the non-locked energy storage inverter, obtain the discharging margin; according to the missing power, the charging margin and the discharging margin, obtain the target allocation power of each phase of each energy storage inverter; according to the target allocation power of each phase of each energy storage inverter, perform power output to match the load.

[0006] In some embodiments, determining the locked phase and the unlocked phase based on the initial allocated power of each phase of each energy storage inverter includes: obtaining the corresponding load power; calculating the total output power of each phase based on the initial allocated power of each phase of each energy storage inverter; comparing the total output power of each phase with the corresponding load power; defining the phase whose total output power is less than the corresponding load power as the locked phase; otherwise, it is the unlocked phase.

[0007] In some embodiments, the determining of a locked energy storage inverter and a non-locked energy storage inverter based on the initial allocated power of each phase of each energy storage inverter and the discharge limit of the energy storage battery corresponding to each energy storage inverter includes: calculating the three-phase total output power of each energy storage inverter based on the initial allocated power of each phase of each energy storage inverter; defining an energy storage inverter whose three-phase total output power is equal to the discharge limit of the energy storage battery as a locked energy storage inverter; and defining an energy storage inverter whose three-phase total output power is less than the discharge limit of the energy storage battery as a non-locked energy storage inverter.

[0008] In some embodiments, determining the missing power of the locked phase of the locked energy storage inverter based on the locked energy storage inverter and the locked phase includes: obtaining the sum of the initially allocated powers of the non-locked energy storage inverters in the locked phase; the difference between the load power corresponding to the locking and the sum of the initially allocated powers of the non-locked energy storage inverters in the locked phase is the sum of the missing powers; and determining the missing power of the locked phase of each locked energy storage inverter based on the sum of the missing powers, the number of the locked energy storage inverters, and the maximum allowable discharge power.

[0009] In some embodiments, obtaining the charging margin based on the initial allocated power of the non-locked phase of the locked energy storage inverter includes: determining whether the initial allocated power of the non-locked phase in the locked energy storage inverter is zero; if the initial allocated power of the non-locked phase is not zero, it indicates that the non-locked phase is used to power the load, and it is determined that the non-locked phase cannot perform a charging operation; if the initial allocated power of the non-locked phase is zero, it indicates that the non-locked phase is not used to power the load, and it is determined that the non-locked phase is a chargeable phase; and obtaining the maximum allowable charging power of the chargeable phase in the locked energy storage inverter as the charging margin.

[0010] In some embodiments, obtaining the discharge margin based on the initial allocated power of the non-locked phase of the non-locked energy storage inverter includes: obtaining the discharge limit of the energy storage battery corresponding to the non-locked energy storage inverter and the maximum allowable discharge power of the non-locked phase of the non-locked energy storage inverter; calculating the discharge margin based on the discharge limit of the energy storage battery corresponding to the non-locked energy storage inverter, the maximum allowable discharge power of the non-locked phase of the non-locked energy storage inverter and the initial allocated power.

[0011] In some embodiments, the target allocated power of each phase of each energy storage inverter is obtained according to the missing power, the charging margin, and the discharging margin, including: determining the non-locked phase for power scheduling in the non-locked energy storage inverter according to the discharging margin and the missing power, and obtaining the first scheduling power of the non-locked phase for power scheduling in the non-locked energy storage inverter; determining the non-locked phase for power scheduling in the locked energy storage inverter according to the charging margin and the missing power, and obtaining the second scheduling power of the non-locked phase for power scheduling in the locked energy storage inverter; obtaining the target allocated power of each phase of each energy storage inverter according to the missing power, the first scheduling power, and the second scheduling power.

[0012] In some embodiments, determining the non-locked phase for the power scheduling in the locked energy storage inverter based on the charging margin and the missing power, and obtaining the second scheduling power of the non-locked phase for the power scheduling in the locked energy storage inverter, includes: obtaining the load power corresponding to the non-locked phase for the power scheduling in the locked energy storage inverter and the discharge limit of the energy storage battery corresponding to the non-locked energy storage inverter; and obtaining the second scheduling power based on the first scheduling power, the load power, and the discharge limit of the energy storage battery.

[0013] In order to solve the above technical problems, another technical solution adopted in the embodiment of the present application is: to provide a power distribution device for a three-phase parallel system, wherein the three-phase parallel system includes at least two energy storage inverters, and the device includes: an acquisition module, wherein the acquisition module is used to obtain the initial distribution power of each phase of each energy storage inverter; a first confirmation module, wherein the first confirmation module is used to determine the locked phase and the unlocked phase according to the initial distribution power of each phase of each energy storage inverter; a second confirmation module, wherein the second confirmation module is used to determine the locked energy storage inverter and the unlocked energy storage inverter according to the initial distribution power of each phase of each energy storage inverter and the discharge limit of the energy storage battery corresponding to each energy storage inverter; a missing power calculation module, wherein the missing power calculation module is used to determine the locked energy storage inverter and the unlocked energy storage inverter according to the initial distribution power of each phase of each energy storage inverter and the discharge limit of the energy storage battery corresponding to each energy storage inverter; and a missing power calculation module. Lock the energy storage inverter and the locked phase, determine the missing power of the locked phase of the locked energy storage inverter; a charging margin calculation module, the charging margin calculation module is used to obtain the charging margin according to the initial allocation power of the non-locked phase of the locked energy storage inverter; a discharge margin calculation module, the discharge margin calculation module is used to obtain the discharge margin according to the initial allocation power of the non-locked phase of the non-locked energy storage inverter; a power scheduling calculation module, the power scheduling calculation module is used to obtain the target allocation power of each phase of each energy storage inverter according to the missing power, the charging margin and the discharge margin; a power distribution module, the power distribution module is used to output power to match the load according to the target allocation power of each phase of each energy storage inverter.

[0014] To solve the above technical problems, another technical solution adopted in the embodiment of the present application is: providing a three-phase parallel system, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the method described above.

[0015] Different from the related art, the present application provides a three-phase parallel system and its power distribution method and device. 1. Adopting a multi-stage progressive calculation process of "initial distribution → locked phase / locked energy storage inverter → margin redistribution", by obtaining key parameters such as load power, charging margin, discharge margin and missing power of each phase in real time, combined with a dynamic adjustment mechanism, it overcomes the limitation that traditional single-step distribution is difficult to cope with multi-phase load changes. 2. Based on the initial power distribution, the locked phase is obtained in combination with the load power, and the locked energy storage inverter is screened in combination with the discharge limit of the energy storage battery to achieve accurate positioning of the system bottleneck and provide a decision-making basis for subsequent cross-phase compensation. 3. Propose a joint calculation of the charging margin (the remaining amount of the non-locked phase of the locked energy storage inverter) and the discharging margin (the additional power that the non-locked inverter can generate), and compensate for the missing power of the locked phase through margin redistribution, breaking through the limitations of traditional independent distribution of the same phase, allowing the energy storage inverter to dynamically allocate power between different phases, and realize energy interaction between the three phases. 4. Through the coordinated calculation of global margins, cross-phase power is coordinated and dispatched among multiple energy storage inverters to avoid overloading of a single unit while maximizing the overall load capacity of the system. This solves the problems of rigid inter-phase power and single-point bottlenecks that restrict overall performance in traditional parallel systems, significantly improving the load adaptability and operational reliability of the parallel system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] One or more embodiments are exemplarily illustrated by corresponding drawings, which do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0017] Figure 1 This is a schematic structural diagram of a three-phase parallel system provided in an embodiment of the present application;

[0018] Figure 2 This is a flow chart of a power distribution method for a three-phase parallel system provided in an embodiment of the present application;

[0019] Figure 3 This is a flow chart of a target power allocation calculation process provided by an embodiment of the present application;

[0020] Figure 4 This is a schematic block diagram of the structure of a power distribution device for a three-phase parallel system provided in an embodiment of the present application;

[0021] Figure 5 Schematic diagram of the hardware structure of a three-phase parallel system for executing a power distribution method for a three-phase parallel system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0023] It should be noted that, if there is no conflict, the various features in the embodiments of the present application can be combined with each other and are all within the scope of protection of the present application. In addition, although the functional modules are divided in the device schematics and the logical order is shown in the flow charts, in some cases, the steps shown or described can be performed in a different order than the module division in the device schematics or the order in the flow charts.

[0024] Unless otherwise defined, all technical and scientific terms used in this specification have the same meanings as those commonly understood by those skilled in the art to which this application belongs. The terms used in this specification are intended only to describe specific embodiments and are not intended to limit this application. The term "and / or" as used in this specification includes any and all combinations of one or more of the relevant listed items.

[0025] See also Figure 1 , Figure 1 This is a schematic block diagram of the structure of a three-phase parallel system provided in an embodiment of the present application. Figure 1 As shown, the three-phase parallel system 100 comprises multiple stand-alone systems 10. Each stand-alone system 10 is a standardized three-phase energy storage system, integrating an energy storage battery and an energy storage inverter. Each subsystem utilizes a modular design to achieve plug-and-play scalability. The AC side of each stand-alone system's energy storage inverter utilizes low-impedance parallel connection technology to connect to a common bus, forming a multi-machine parallel power supply network that is synchronously connected to the load and grid access points. Each stand-alone system 10 establishes a real-time data exchange link with the higher-level energy management system (EMS) and grid dispatch center via a dual-mode communication channel using power carrier and CAN bus. This enables detection of the state-of-charge (SOC) status of the energy storage battery, synchronization of inverter operating parameters, and dynamic sensing of grid and load demand.

[0026] In this embodiment, a three-phase parallel system 100 includes at least two parallel stand-alone systems 10, specifically a three-phase energy storage system. The energy storage inverter converts direct current (DC) into alternating current (AC), and vice versa. Each energy storage inverter is capable of controlling the voltage and power output of each phase and adjusting the charge and discharge state according to the needs of the energy storage battery. Each phase of each inverter has a corresponding maximum allowable charge / discharge power, which is primarily limited by the inverter hardware itself, such as the rated parameters of the power devices. When the inverter models are the same, the maximum allowable charge / discharge power of each phase of each inverter is the same. Each energy storage battery may include multiple energy storage cells, each of which has different discharge power limits and charge power limits depending on its state of charge (SOC) value.

[0027] The three-phase parallel system 100 has three core operating modes: energy storage priority mode, hybrid power supply mode, and grid charging mode. When the energy storage battery of the three-phase parallel system 100 has sufficient energy, it adopts the energy storage priority mode, and the parallel system fully assumes the load power supply. The grid plays an important auxiliary role in the three-phase parallel system 100, especially when the load demand exceeds the discharge capacity of the three-phase parallel system 100. The grid provides an additional source of power. At this time, the three-phase parallel system 100 adopts the hybrid power supply mode. When the energy storage battery is insufficient, the three-phase parallel system 100 automatically switches to the grid charging mode. The grid provides power to the energy storage inverter to charge the battery, and the load is directly supplied by the grid. After the inverter obtains AC power from the grid, it converts it into DC power and charges the battery, ensuring that the energy storage system has sufficient power to meet future load demands.

[0028] The power grid and the three-phase parallel system 100 work together to ensure a stable supply of load power. Through a power scheduling algorithm, the grid can supplement the energy storage system's shortfalls when necessary, or absorb excess power when the energy storage system's output exceeds the load, preventing power waste.

[0029] In a parallel system, load matching can typically be achieved through inverter sequencing or evenly splitting, provided the total discharge limit of the BMS (Battery Management System) allows this approach. However, in some special cases, even if the total discharge limit of the parallel system's BMS is large enough to theoretically match the load demand, the significant differences in the discharge state of power (SOP) of the individual energy storage batteries within the system prevent the full utilization of the discharge capacity of all energy storage batteries, thus failing to fully meet the load demand. In this case, even if the total discharge limit is not exceeded, the discharge capacity of some energy storage batteries within the system is limited, forcing some loads to still require grid power. This situation is common in systems with uneven state of charge (SOC) of the energy storage batteries or significant variations in discharge efficiency, requiring additional grid support during peak load periods. Ideally, users or developers would prefer that the load be fully powered by the parallel system when the system's discharge power allows.

[0030] To do this, see Figure 2 , Figure 2 This is a flow chart of a power distribution method for a three-phase parallel system provided by an embodiment of the present application. Figure 2 As shown, the method is applied to the above-mentioned three-phase parallel system 100, and the method includes steps S101-S108:

[0031] S101: Obtaining the initial distributed power of each phase of each energy storage inverter.

[0032] First, you need to identify all grid-connected energy storage inverters in the parallel system. These energy storage inverters are typically three-phase inverters, capable of outputting three-phase AC power, and each inverter can allocate power to different phases (L1, L2, and L3). In this step, you need to determine the basic information of these inverters, including their serial number, rated power, current load, status, and the power output capacity of each phase.

[0033] Secondly, in order to obtain accurate initial power distribution, it is necessary to monitor the real-time working status of each energy storage inverter, including the following aspects: Load information: Obtain the current load power of each phase of each inverter. For example, the load power corresponding to phases L1, L2, and L3 of inverter A. Discharge status: The discharge status of the inverter is the discharge capacity of the energy storage battery. If the inverter is charging, the discharge power is zero; if it is discharging, the output power of each phase of the inverter is recorded. Battery management system (BMS) information: Obtain information such as the battery's state of health (SOH), remaining battery capacity (SOC), and charge / discharge power limit through the BMS, which helps calculate the target output power of each phase of each inverter.

[0034] Next, each energy storage inverter will have a preliminary power allocation, which is called the primary power allocation before secondary power scheduling. Specifically, the primary power allocation refers to the power initially allocated to each phase of each inverter before optimized scheduling, based on the current energy storage battery status, load demand, and the inverter's maximum allowable charge / discharge power. The primary power allocation can be based on existing strategies such as phase-by-phase sequential loading, equal loading, and SOC-based proportional loading.

[0035] The key to this step is real-time monitoring and collection of each phase's load power, battery status (battery charge and discharge limits), and the inverter's maximum allowable charge / discharge power, allowing for initial power allocation. Accurately capturing this initial power allocation lays the foundation for subsequent power scheduling, missing power calculation, and charge and discharge margin assessment.

[0036] S102: Determine a locked phase and a non-locked phase according to the initial distributed power of each phase of each energy storage inverter.

[0037] Determining locked phases and unlocked phases based on the initial allocated power of each phase of each energy storage inverter includes: obtaining the corresponding load power; calculating the total output power of each phase based on the initial allocated power of each phase of each energy storage inverter; comparing the total output power of each phase with the corresponding load power; defining a phase whose total output power is less than the corresponding load power as a locked phase; otherwise, it is an unlocked phase.

[0038] To determine the locked phase, the load power corresponding to each phase (L1, L2, and L3) must first be obtained. These load power values are typically determined by the system's load requirements or external load conditions. Each load power represents the total power demanded by the energy storage inverter for each phase. For example, assuming the load power on phase L1 is 4 kW, this means the total power demand on phase L1 of the energy storage inverter is 4 kW.

[0039] Next, obtain the initial power allocation for each phase of each energy storage inverter. It should be understood that the initial power allocation for each phase of each energy storage inverter refers to the power allocated by the inverter according to the currently configured allocation strategy. The initial power allocation for each inverter depends on the battery status, load demand, and the inverter's output capacity.

[0040] Next, calculate the total output power of each phase. It's understandable that the total output power of each phase is the sum of the power allocated by each inverter on that phase. For example, for phase L1, assuming there are two inverters, inverter A's initial power allocation on phase L1 is 2 kW, and inverter B's initial power allocation on phase L1 is 2 kW, then the total output power of phase L1 is 4 kW.

[0041] Next, the total output power of each phase is compared to the load power. It can be understood that the total output power of each phase is compared to the corresponding load power. The comparison results are as follows: If the total output power of a phase is less than the load power, it means that the phase cannot meet the load demand and is a "locked phase" and needs to enter the locked state. If the total output power of a phase is greater than or equal to the load power, then the phase can meet the load demand and is considered an "unlocked phase." For example, if the load power of phase L1 is 4 kW and the total output power of phase L1 is 4 kW, then phase L1 is an unlocked phase because its output power meets the load demand. If the load power of phase L1 is 4 kW, but the total output power of phase L1 is 3 kW, then phase L1 is a locked phase.

[0042] Finally, the locked phase is determined and the locked phase flag is output. It can be understood that by comparing the total output power and load power of each phase, the locked phase and the unlocked phase can be obtained: if the total output power of a phase is less than the load power, the phase is a locked phase. For example, if the total output power of phase L1 is 3 kW and the load power is 4 kW, then phase L1 is marked as a locked phase (lockphase[1] = 1). Conversely, if the total output power of a phase is greater than or equal to the load power, it is an unlocked phase. In practical applications, this comparison process can be implemented through programming to automatically check and set the locking status of each phase. Finally, the system will output the locking status of each phase. The purpose of marking the locked phase is to make corresponding power adjustments in subsequent power scheduling. The locked phase needs to borrow power from the unlocked phases of other inverters to balance the load demand.

[0043] This embodiment accurately calculates the total output power of each phase and compares it with the corresponding load power to accurately identify which phases cannot meet the load demand, thereby determining the locked phase. By identifying the locked phase, the system can perform targeted power scheduling, allowing the phase that cannot meet the load to borrow power from other phases, avoiding the overall system performance degradation caused by local power shortages, and improving the load adaptability and efficiency of the three-phase parallel system.

[0044] S103: Determine a locked energy storage inverter and a non-locked energy storage inverter according to the initial distributed power of each phase of each energy storage inverter and the discharge limit of the energy storage battery corresponding to each energy storage inverter.

[0045] Determining locked energy storage inverters and non-locked energy storage inverters based on the initial allocated power of each phase of each energy storage inverter and the discharge limit of the energy storage battery corresponding to each energy storage inverter includes: calculating the three-phase total output power of each energy storage inverter based on the initial allocated power of each phase of each energy storage inverter; defining an energy storage inverter whose three-phase total output power is less than the discharge limit of the energy storage battery as a non-locked energy storage inverter, and vice versa, as a locked energy storage inverter.

[0046] First, based on the initial power allocation for each phase of each energy storage inverter, the total three-phase output power of each energy storage inverter is calculated. In step S101, the initial power allocation data for each phase of all energy storage inverters has been obtained. For example, if the initial power allocation for energy storage inverter A on phase L1 is 2 kW, the initial power allocation for phase L2 is 0 kW, and the initial power allocation for phase L3 is 2 kW, then the total three-phase output power of energy storage inverter A is 4 kW.

[0047] Next, obtain the discharge limit of the energy storage battery corresponding to each energy storage inverter. The discharge limit of an energy storage battery indicates the maximum power or energy that the battery can provide from stored energy. The discharge limit of an energy storage battery is generally related to the battery state of charge (SOC), battery temperature, and battery state of health (SOH). The battery's BMS (battery management system) automatically calculates the corresponding discharge limit based on these factors. Typically, at low SOC, the BMS actively limits the discharge current, reducing the discharge (power) limit. At medium to high SOC, the discharge (power) limit typically reaches the nominal value. At high SOC, the upper limit of the discharge (power) limit is not limited by SOC, but the charge (power) limit is reduced. At low battery temperatures (e.g., <0°C) or high battery temperatures (e.g., >45°C), the discharge power is forcibly derated, meaning the discharge limit is reduced. The lower the SOH, the lower the discharge limit.

[0048] Next, the three-phase total output power of each energy storage inverter is compared with the discharge limit of the corresponding energy storage battery. An energy storage inverter whose three-phase total output power equals the discharge limit of the energy storage battery is defined as a locked energy storage inverter; an energy storage inverter whose three-phase total output power is less than the discharge limit of the energy storage battery is defined as an unlocked energy storage inverter. It can be understood that by comparing the three-phase total output power of each energy storage inverter with the discharge limit of the corresponding energy storage battery, it is possible to determine which energy storage batteries still have excess power (remaining available power) and which energy storage batteries have fully utilized their power due to insufficient energy. The specific operation is as follows: If the three-phase total output power of a certain energy storage inverter equals the discharge limit of the corresponding energy storage battery, the energy storage inverter can no longer provide excess power and is marked as a locked energy storage inverter. If the three-phase total output power of the energy storage inverter is less than the discharge limit of the corresponding energy storage battery, the energy storage inverter can still provide excess power and is marked as an unlocked energy storage inverter. For example, for the aforementioned energy storage inverter A, the initial allocated power for its L1, L2, and L3 phases is 2 kW, 0 kW, and 2 kW, respectively. When the energy storage battery's discharge limit is 4 kW, energy storage inverter A is marked as a locked energy storage inverter. When the energy storage battery's discharge limit is 6 kW, energy storage inverter A is marked as an unlocked energy storage inverter. Finally, based on the above power comparison, the system outputs which energy storage inverters are marked as locked energy storage inverters and which are marked as unlocked energy storage inverters. These locked energy storage inverters require special handling in subsequent power scheduling, and load demand must be met by borrowing power from unlocked energy storage inverters.

[0049] This embodiment effectively identifies which energy storage inverters have surplus power and which have exhausted their power by comparing the total three-phase output power of each energy storage inverter with the discharge limit of the corresponding energy storage battery. By clearly marking locked and unlocked energy storage inverters, the system can promptly adjust the power allocation strategy and lock inverters that have exhausted their power. This ensures that the total three-phase power output of the energy storage inverter does not exceed the maximum discharge capacity of the corresponding energy storage battery, preventing overload and battery loss. It also ensures that the entire parallel system can operate smoothly and stably, improving system safety and efficiency.

[0050] S104: Determine the missing power of the locked phase of the locked energy storage inverter according to the locked energy storage inverter and the locked phase.

[0051] According to the locked energy storage inverter and the locked phase, the missing power of the locked phase of the locked energy storage inverter is determined, including: obtaining the sum of the initial distribution powers of the non-locked energy storage inverters in the locked phase; the difference between the load power corresponding to the lock and the sum of the initial distribution powers of the non-locked energy storage inverters in the locked phase is the sum of the missing powers; according to the sum of the missing powers, the number of locked energy storage inverters and the maximum allowable discharge power, the missing power of the locked phase of each locked energy storage inverter is determined.

[0052] First, the sum of the initial allocated powers of the non-locked energy storage inverters in the locked phase is obtained. It is understandable that in the locked phase, the system needs to identify which energy storage inverters are marked as non-locked energy storage inverters. Then, the initial allocated powers of these non-locked energy storage inverters in that locked phase are obtained and summed. For example, phase L1 is the locked phase, energy storage inverter B is the locked inverter, energy storage inverter A is the non-locked energy storage inverter, and energy storage inverter C is the non-locked energy storage inverter. Assuming that in phase L1, the initial allocated power of inverter A is 1 kW and the initial allocated power of inverter C is 2 kW, the sum of the initial allocated powers of the non-energy storage inverters in the locked phase is 3 kW.

[0053] Next, calculate the total missing power. This is the difference between the total power required by the load and the power provided by the non-locked inverter. For example, if the load power on phase L1 is 5 kW and the total initial power allocated by the non-locked energy storage inverter is 3 kW, the total missing power is 2 kW.

[0054] Thirdly, the missing power is distributed in a sequential / equal / proportional / unfixed manner. It is understandable that based on the sum of the missing power of the locked phases, the system needs to reasonably distribute this power to all locked energy storage inverters. This process can be distributed in the following ways:

[0055] Equal distribution method: The sum of missing power is evenly distributed to all locked energy storage inverters. The power allocated to each locked energy storage inverter is:

[0056]

[0057] For example, assuming the total missing power is 2 kW and there are two locked energy storage inverters, the shared power is 1 kW.

[0058] Sequential allocation: Allocate the missing power to each locked energy storage inverter according to a specific sequence rule. For example, the missing power can be allocated based on factors such as the inverter's output capacity and load priority. If the maximum allowable discharge power of each locked energy storage inverter is different, the inverter with the smaller power can be allocated first until its maximum discharge power limit is reached. Then, allocation can be continued to the next inverter until the missing power is fully allocated.

[0059] Proportional allocation method: According to the unused margin of each locked energy storage inverter in the locked phase, the missing power is allocated to each locked energy storage inverter in a certain proportion.

[0060] For each energy storage inverter, the maximum allowable discharge power per phase is typically determined based on the inverter's power device parameters. This represents the maximum power the inverter can safely and stably output. For the same inverter model, the maximum allowable discharge power per phase is typically the same for each inverter.

[0061] The unused margin of each locked energy storage inverter in the locked phase refers to the difference between the maximum allowable discharge power and the initial distribution power.

[0062] For example, assuming that the locked phase is L3, inverter A is a non-locked energy storage inverter, inverter B and inverter C are both locked energy storage inverters, the initial allocated power of inverter B's L3 phase is 1 kW, the initial allocated power of inverter C's L3 phase is 0 kW, the sum of the missing power is 4 kW, and the maximum allowable discharge power of each phase of each energy storage inverter is 3 kW; then the unused margin of inverter B is 2 kW, the unused margin of inverter C is 3 kW, the missing power of inverter B is proportionally distributed as 2 / (2+3)*4=1.6 kW, and the missing power of inverter C is proportionally distributed as 3 / (2+3)*4=2.4 kW.

[0063] Variable allocation: Allocation is not based on fixed standards but can be flexibly determined based on actual conditions and a combination of factors. Using the example of the proportional allocation method, for example, the missing power of inverter B could be allocated as 1.8 kW, and the missing power of inverter C could be allocated as 2.2 kW.

[0064] It is understandable that, regardless of whether the equal distribution method, sequential distribution method, proportional distribution method, or variable quota distribution method is used, it is necessary to ensure that the sum of the missing power and the initial distribution power of each locked energy storage inverter does not exceed its maximum allowable discharge power. This is to prevent overload operation and protect the safety of the energy storage battery and energy storage inverter. If the calculated missing power exceeds the maximum allowable discharge power of a certain inverter, the inverter can only be allocated the maximum allowable discharge power. For example, according to the equal distribution method, the actual distribution can be limited by the following formula:

[0065] ;

[0066] in, is the maximum allowable discharge power of each energy storage inverter; It is the initial distribution power of the locked phase of each energy storage inverter.

[0067] Finally, according to the above allocation strategy, the missing power of each locked energy storage inverter is output as the basis for subsequent power scheduling. These inverters will output according to the calculated missing power until the load power is fully met as much as possible.

[0068] This embodiment rationally allocates and locks the missing power of the energy storage inverters, ensuring that each inverter provides the required power within its maximum allowable discharge power range. This not only helps balance the power output of each energy storage inverter in the system, preventing inverter overload, but also optimizes power scheduling efficiency, ensuring that the entire parallel system can stably and smoothly provide the required power to the load.

[0069] S105: Obtaining the charge margin according to the initial distribution power of the non-locked phase of the locked energy storage inverter.

[0070] Obtaining a charging margin based on an initial allocated power of a non-locked phase of a locked energy storage inverter, including: determining whether the initial allocated power of the non-locked phase in the locked energy storage inverter is zero; if the initial allocated power of a non-locked phase is not zero, it indicates that the non-locked phase is used to power a load, and determining that the non-locked phase cannot be charged; if the initial allocated power of a non-locked phase is zero, it indicates that the non-locked phase is not used to power a load, and determining that the non-locked phase is a chargeable phase; and obtaining a maximum allowable charging power of the chargeable phase in the locked energy storage inverter as the charging margin.

[0071] First, the system needs to determine whether the initial allocated power of the non-locked phase in the locked energy storage inverter is zero. Specifically, for each locked energy storage inverter, check its initial allocated power in the non-locked phase. If the power value is not zero, it means that the non-locked phase has been used to provide power to the load; if the initial allocated power is zero, it means that the non-locked phase is not powered by the load, so it can be used for charging. It can be understood that if the initial allocated power is not zero, it means that the non-locked phase has been used to power the load, so the phase cannot be charged, and the charging margin is zero in this case. If the initial allocated power is zero, it means that the non-locked phase is not used to power supply, so the phase is considered to be a rechargeable phase. At this point, the system can proceed to the next step to calculate the charging margin.

[0072] Next, for each locked energy storage inverter, obtain the maximum allowable charging power for the chargeable phase. This maximum allowable charging power is typically determined based on the parameters of the energy storage inverter's power components and represents the maximum power the inverter can safely and stably input. When all inverters are the same model, the maximum allowable charging power for each phase is generally the same.

[0073] Finally, after determining the chargeable phases, the system calculates the charge margin based on the maximum allowable charging power of the chargeable phases. The charge margin refers to the amount of power available for charging in the non-locked phases under the current load demand. The calculation formula is: Charge margin = Maximum allowable charging power - Initially allocated power.

[0074] Since the initial allocated power of the rechargeable phase is 0, the charging margin of the rechargeable box is equal to the maximum allowable charging power, that is: charging margin = maximum allowable charging power.

[0075] For example, if the maximum permissible charging power is 2 kW, the remaining charging capacity is 2 kW.

[0076] Finally, the remaining charge capacity is output based on the above calculations. This information will serve as the basis for subsequent power scheduling, coordinating the operation of other inverters in the system and ensuring that the energy storage inverter can charge or discharge as needed.

[0077] This embodiment identifies which inverters' non-locked phases are not being used to power the load, determines their charging capacity, and calculates the remaining charge capacity. This provides an important basis for system power scheduling, ensuring a balance between load demand and charging requirements, thereby efficiently utilizing the operating capacity of each inverter. By properly arranging charging and discharging, the efficiency of the energy storage system can be maximized, energy utilization can be optimized, over-discharge or over-charging can be prevented, and the reliability and endurance of the system can be enhanced.

[0078] S106: Obtaining a discharge margin according to the initial distribution power of the non-locked phase of the non-locked energy storage inverter.

[0079] Obtaining a discharge margin according to an initial allocated power of a non-locked phase of a non-locked energy storage inverter includes: obtaining a discharge limit value of an energy storage battery corresponding to the non-locked energy storage inverter and a maximum allowable discharge power of the non-locked phase of the non-locked energy storage inverter; and calculating the discharge margin according to the discharge limit value of the energy storage battery corresponding to the non-locked energy storage inverter, the maximum allowable discharge power of the non-locked phase of the non-locked energy storage inverter, and the initial allocated power.

[0080] First, it is necessary to obtain the discharge limit value of the energy storage battery corresponding to the non-locked energy storage inverter.

[0081] Secondly, the maximum allowable discharge power of the non-locked phase of the non-locked energy storage inverter is obtained.

[0082] Again, the initial distributed power of the non-locked phase of the non-locked energy storage inverter is obtained.

[0083] Finally, the discharge margin is calculated based on the above parameters. The calculation formula for the discharge margin is as follows:

[0084]

[0085] in, is the maximum allowable discharge power of the non-locked phase, is the initial power distribution of the non-locked phase, is the discharge limit of the energy storage battery corresponding to the inverter, It is the sum of the primary distributed power of each phase.

[0086] Through this formula, the system takes into account the maximum allowable discharge power of each phase, the initial distribution power and the discharge limit of the energy storage battery to derive the available discharge margin of the non-locked inverter.

[0087] For example, taking inverter A as an example, L3 phase is the locked phase, and the initial power distribution of L3 phase is 2kW. The maximum allowable discharge power for phases L1 and L2 is 3kW (the maximum allowable discharge power for phases L1 and L2). The initial power distribution for phase L1 is 2kW, and the initial power distribution for phase L2 is 1kW. The discharge limit of the energy storage battery is 6kW. According to the formula, for phase L1, the discharge margin is min{3-2, 6-(2+1+2)}=1kW. For phase L2, the discharge margin is min{3-1, 6-(2+1+2)}=1kW.

[0088] This embodiment rationally calculates the discharge margin by comprehensively considering the maximum allowable discharge capacity of each inverter at different phases, the discharge limit of the energy storage battery, and the initial power allocation. This ensures that the non-locked energy storage inverter has sufficient available power to meet system requirements, avoiding power shortages caused by the discharge limit of the energy storage battery, and preventing excessive system discharge or damage to battery safety. Furthermore, by ensuring reasonable power allocation, it can effectively balance the inverter load, optimize energy management, and improve the overall operating efficiency and stability of the system.

[0089] S107: Obtain target allocated power for each phase of each energy storage inverter according to the missing power, the charge margin, and the discharge margin.

[0090] See also Figure 3 , Figure 3 This is a flow chart of a target power allocation calculation process provided by an embodiment of the present application. Figure 3 As shown, according to the missing power, charging margin and discharging margin, the target allocated power of each phase of each energy storage inverter is obtained, including steps S1071-S1073:

[0091] S1071: Determine a non-locked phase for power scheduling in the non-locked energy storage inverter according to the discharge margin and the missing power, and obtain a first scheduling power of the non-locked phase for power scheduling in the non-locked energy storage inverter.

[0092] First, the missing power of the locked phase of the energy storage inverter can be obtained by the above step S104, which is recorded as . Secondly, the discharge margin of the non-locked energy storage inverter can be obtained from step S106 to determine which phases can provide power. Select the phase that can provide discharge power, record it as the first scheduling phase, and ensure that the discharge margin of this phase is greater than or equal to the missing power. Finally, calculate the first scheduling power. It can be understood that, assuming the discharge margin of the first scheduling phase is , then the first scheduling power The calculation formula is:

[0093]

[0094] In addition, it is also necessary to ensure that after power scheduling and allocation, the sum of the allocated power of each phase of the energy storage inverter does not exceed the total battery discharge limit of the energy storage inverter (that is, the discharge limit of the energy storage battery corresponding to the above-mentioned energy storage inverter), that is:

[0095]

[0096] For example, assuming two energy storage inverters, phase L3 of locked energy storage inverter B is locked and has a missing power of 1 kW, and the discharge margins of phases L1 and L2 of non-locked energy storage inverter A are 0 kW and 2 kW, respectively. This means that phase L2 of non-locked energy storage inverter A is determined to be available for power scheduling. According to the above formula, the first scheduling power is 1 kW, meaning that phase L2 of non-locked energy storage inverter A will be allocated 1 kW for power scheduling. Furthermore, if the discharge margins of phases L1 and L2 of non-locked energy storage inverter A are 1 kW and 2 kW, combined with the missing power, phase L1 is determined to be the phase for power scheduling. It can be understood that ensuring the discharge margin of the non-locked phase is greater than or equal to the missing power allows the non-locked phase with the smallest discharge margin to be selected for power scheduling while still meeting power scheduling requirements. Finally, after power redistribution, the sum of the allocated powers of each phase of the energy storage inverter must not exceed the total battery discharge limit of the energy storage inverter. It can be understood that, for example, after the secondary power distribution, the corresponding powers of L1, L2 and L3 of the non-locked inverter A are 2kW, 1kW, and 2kW, and the total battery discharge limit of the non-locked inverter A is 6 kW. According to the above formula, the total battery discharge limit condition is also met after the secondary power distribution, that is, the first power scheduling is reasonable.

[0097] S1072: Determine, based on the charge margin and the missing power, a non-locked phase for power scheduling in the locked energy storage inverter, and obtain a second scheduling power of the non-locked phase for power scheduling in the locked energy storage inverter.

[0098] Determining a non-locked phase for power scheduling in a locked energy storage inverter based on the charge margin and the missing power, and obtaining a second scheduling power of the non-locked phase for power scheduling in the locked energy storage inverter, including: obtaining a load power corresponding to the non-locked phase for power scheduling in the locked energy storage inverter and a discharge limit of an energy storage battery corresponding to the non-locked energy storage inverter; and obtaining the second scheduling power based on the first scheduling power, the load power, and the discharge limit of the energy storage battery.

[0099] First, the non-locked phases used for power scheduling and the first scheduling power are known from step S1071. Based on this, the charge margin of the locked energy storage inverter is obtained from step S105, and the phases that can be used for charging are determined. The chargeable phases are selected and recorded as the second scheduling phase.

[0100] Secondly, calculate the second dispatch power. It is understandable that when performing the second dispatch power, it is necessary to ensure the overall power balance of the second dispatch phase. Among them, the second dispatch power calculation formula is as follows:

[0101] ;

[0102] In addition, it is also necessary to ensure that after power scheduling and allocation, the sum of the allocated power of each phase of the energy storage inverter does not exceed the total battery discharge limit of the energy storage inverter (the discharge limit of the energy storage battery corresponding to the above-mentioned energy storage inverter), that is:

[0103]

[0104] Furthermore, it is necessary to ensure that the overall power of the second scheduling phase meets the corresponding load power demand.

[0105] For example, using step S1071 as an example, it is known that after the secondary power distribution of non-locked inverter A, the corresponding powers are 2 kW, 1 kW, and 2 kW. Assume that the load power of phase L2 is 0 kW, the total battery discharge limit of locked inverter B is 2 kW, and the corresponding powers of the non-locked phase of locked inverter B after the initial power distribution are 2 kW and 0 kW. The charge margin of the non-locked phase (phase L2) of locked inverter B is 2 kW, and the corresponding load power of L2 is 0 kW. According to the above formula, the second dispatch power of phase L2 of locked inverter B is -1 kW. At this point, it is also necessary to determine whether the sum of the power of each phase of locked inverter B does not exceed the total battery discharge limit of the energy storage inverter, that is, (2 + (-1) + 1) = 2. In addition, it is necessary to calculate whether the overall power of the second dispatched phase meets its corresponding load power requirement, that is, 1 + (-1) = 0. Based on this, the second power dispatch is reasonable.

[0106] S1073: Obtain target allocated power for each phase of each energy storage inverter according to the missing power, the first dispatching power, and the second dispatching power.

[0107] It is understood that after obtaining the missing power, the first dispatch power, and the second dispatch power, the first dispatch phase for power dispatch, the second dispatch phase for power dispatch, and the phase for borrowing power (the locked phase of the locked inverter) are also determined. Based on this, the target power allocation for each phase of each energy storage inverter can be obtained. This process requires calculating the power allocation for all phases to ensure that the missing power is fully compensated. It also calculates the total power allocation for all energy storage inverters to ensure that the discharge limit and maximum allowable charge and discharge power of the energy storage battery are met. It is understood that this process confirms whether the power allocation is reasonable, that is, to ensure that the total power allocation meets the power dispatch requirements. If the allocation is unreasonable, the dispatch power of the non-locked phases is adjusted to meet the power limit.

[0108] This embodiment ensures a balanced power supply and demand by properly scheduling the power of non-locked energy storage inverters and locked energy storage inverters, thus avoiding power waste or shortages. On the one hand, the discharge margin of non-locked energy storage inverters is fully utilized, enabling the system to more effectively utilize stored energy and improve the overall power distribution efficiency of the system. On the other hand, power scheduling balances the power distribution between inverters, ensuring that system instability due to power overload or power shortage will not occur, thereby improving the reliability of the energy storage system. In addition, after power scheduling, it is ensured that the discharge power and charging power of all energy storage inverters are within a reasonable range to avoid damage to batteries or equipment.

[0109] S108: Distribute power according to the target of each phase of each energy storage inverter and output power to match the load.

[0110] After obtaining the target allocated power of each phase of each energy storage inverter according to the above steps, each energy storage inverter needs to perform actual power output according to the target allocated power.

[0111] First, the power output of the non-locked energy storage inverter. Taking energy storage inverter A as an example: A's L2 phase needs to discharge 1 kW according to the calculation results of S107. Ensure that A's L2 phase power output reaches the set value and remains stable. Monitor A's battery discharge status to ensure that it does not exceed its battery discharge limit. If the power output is unstable, adjust it. For example, if the L2 phase power output fluctuates excessively, adjust the PWM (pulse width modulation) control strategy. If the battery voltage drops abnormally, it may be necessary to limit the discharge power.

[0112] Secondly, lock the power regulation of the energy storage inverter. Taking energy storage inverter B as an example: B's L2 phase needs to absorb 1 kW (i.e., charge) to balance the system; monitor B's battery charge status to ensure that it does not exceed its charging power limit; ensure that B's L3 phase receives the required 1 kW to meet the load demand; if B's battery charging is limited, adjust the power distribution of other phases to maintain overall system stability.

[0113] Secondly, load power matching. It's understandable that the load needs to receive the inverter's output power in real time to ensure grid-side power balance. The voltage and current sampling feedback system adjusts the power output of each phase in real time to prevent power shortages or overloads. If the load demand changes (for example, an increase in the power demand for phase L3), the system should quickly adjust the power output to dynamically adapt to the load.

[0114] Finally, during the power output process, the system needs to perform continuous monitoring to ensure the accuracy of power matching and make adjustments based on feedback information. Specific monitoring content includes: Real-time monitoring of voltage and current: Using current sensors, Hall sensors, and other devices, the output power data of each phase of the energy storage inverter is collected in real time; if a power deviation is found (for example, the target is 1kW, but the actual output is only 0.8 kW), the output power of the inverter needs to be adjusted. Battery status monitoring: Monitor the battery SOC (State of Charge) of the energy storage inverter; prevent overcharging and over-discharging, and adjust the power output limit when necessary. System safety control: Set abnormal status detection, such as overtemperature, overload, short circuit, etc., and take protective measures when an abnormality occurs; optimize power distribution through intelligent scheduling algorithms to make power output more stable.

[0115] This embodiment ensures the stability, safety, and efficiency of power scheduling through intelligent control strategies and real-time monitoring feedback. Ultimately, it enables the system to achieve precise power allocation, improve energy utilization, and ensure reliable system operation.

[0116] The power scheduling process of the power distribution method for the three-phase parallel system proposed in the above embodiment is explained below in conjunction with Tables 1 to 10:

[0117] Table 1 - Initial power distribution

[0118]

[0119] Table 2 - Secondary distribution power

[0120]

[0121] For Example 1, please refer to Tables 1 and 2, taking a locked energy storage inverter and a locked phase as an example. As shown in Table 1, it is known that the initial power distribution of each phase of the stand-alone system A (energy storage inverter) is 2, 0, 2. The initial power distribution of each phase of the stand-alone system B (energy storage inverter) is 2, 0, 0. The load power of L1, L2, and L3 is 4, 0, 3. The total battery discharge limit of the stand-alone systems A and B is 6 and 2. Assume that the maximum allowable charge and discharge power of each phase is 2. It should be noted that the total battery discharge limit here and in the following is the discharge limit of the energy storage battery described above, which will not be repeated here.

[0122] First, by comparing the total output power and load power of each phase, it can be determined that the locked phase is phase L3, and phases L1 and L2 are non-locked phases. Secondly, by comparing the three-phase total output power of each energy storage inverter and the discharge limit of the corresponding energy storage battery, it can be determined that the single-machine system B is a locked energy storage inverter and the single-machine system A is a non-locked energy storage inverter. Then, the difference between the load power corresponding to the lock and the sum of the initial allocated power of the non-locked energy storage inverter in the locked phase is calculated as the sum of the missing power. According to Table 1, the sum of the missing power is: 3-2=1, that is, the missing power required for phase L3 of the single-machine system B is 1.

[0123] Next, determine whether the initial power distribution of phases L1 and L2 in stand-alone system B is zero to determine the chargeable phase and remaining charge capacity. Table 1 shows that phase L2 in stand-alone system B is a chargeable phase with a remaining charge capacity of 2.

[0124] Next, the discharge margin is obtained based on the initial power distribution of phases L1 and L2 of the single-machine system A. According to Table 1, the discharge margin of phase L2 of the single-machine system A is 2.

[0125] Finally, based on the missing power, charge margin, and discharge margin, the target allocated power for each phase of each energy storage inverter is obtained. Following the power allocation process described in the above embodiment, the data in Table 2 is obtained: the corresponding allocated power for L3 of stand-alone system B is 1 (missing power), the corresponding allocated power for L2 of stand-alone system A is 1 (first dispatch power), and the corresponding allocated power for L2 of stand-alone system B is -1 (second dispatch power). Verification shows that the sum of the secondary allocated power for each phase of stand-alone systems A and B does not exceed their respective total battery discharge limits, the secondary allocated power for each phase does not exceed the maximum allowable charge and discharge power for each phase, and the overall power of each phase is equal to its corresponding load power. That is, after the secondary power allocation, the surplus power in the inverter's energy storage battery just fills the power gap, and there is no need to borrow power from the grid.

[0126] Table 3 - Initial power distribution

[0127]

[0128] Table 4 - Secondary distribution power

[0129]

[0130] For Example 2, please refer to Tables 3 and 4, using a locked energy storage inverter and a locked phase as an example. As shown in Table 3, the initial power distribution for each phase of single-machine system A is 2, 1, and 2. The initial power distribution for each phase of single-machine system B is 2, 0, and 0. The load powers of L1, L2, and L3 are 4, 1, and 3. The total battery discharge limit for single-machine systems A and B is 6 and 2 respectively. Assume that the maximum allowable charge and discharge power per phase is 2.

[0131] First, by comparing the total output power and load power of each phase, it can be determined that the locked phase is phase L3, and phases L1 and L2 are non-locked phases. Secondly, by comparing the three-phase total output power of each energy storage inverter and the discharge limit of the corresponding energy storage battery, it can be determined that the single-machine system B is a locked energy storage inverter and the single-machine system A is a non-locked energy storage inverter. Then, the difference between the load power corresponding to the lock and the sum of the initial allocated power of the non-locked energy storage inverter in the locked phase is calculated as the sum of the missing power. According to Table 3, the sum of the missing power is: 3-2=1, that is, the missing power required for phase L3 of the single-machine system B is 1.

[0132] Next, determine whether the initial power distribution of phases L1 and L2 in stand-alone system B is zero to determine the chargeable phase and remaining charge capacity. Table 3 shows that phase L2 in stand-alone system B is a chargeable phase with a remaining charge capacity of 2.

[0133] Next, the discharge margin is obtained based on the initial power distribution of phases L1 and L2 of the single-machine system A. According to Table 3, the discharge margin of phase L2 of the single-machine system A is 1.

[0134] Finally, based on the missing power, charge margin, and discharge margin, the target allocated power for each phase of each energy storage inverter is obtained. Following the power allocation process described in the above embodiment, the data in Table 4 is obtained: the corresponding allocated power for L3 of stand-alone system B is 1 (missing power), the corresponding reallocated power for L2 of stand-alone system A is 1 (first dispatch power), and the corresponding reallocated power for L2 of stand-alone system B is -1 (second dispatch power). This means that the target powers for each phase of stand-alone system B are 2, -1, and 1, respectively; and the target powers for each phase of stand-alone system A are 2, 2, and 2. Verification shows that the sum of the secondary allocated powers for each phase of stand-alone systems A and B does not exceed the total discharge limit of their respective batteries, the secondary allocated power for each phase does not exceed the maximum allowable charge and discharge power for each phase, and the overall power of each phase is equal to its corresponding load power. This means that after secondary power allocation, the excess power in the inverter's energy storage batteries just fills the power gap, without requiring power from the grid.

[0135] Table 5 - Initial power distribution

[0136]

[0137] Table 6 - Secondary distribution power

[0138]

[0139] For Example 3, please refer to Tables 5 and 6, using a locked energy storage inverter and a locked phase as an example. As shown in Table 5, the initial power distribution for each phase of single-machine system A is 2, 1, and 2. The initial power distribution for each phase of single-machine system B is 2, 0, and 0. The load powers of L1, L2, and L3 are 4, 1, and 4. The total battery discharge limit for single-machine systems A and B is 6 and 2 respectively. Assume that the maximum allowable charge and discharge power per phase is 2.

[0140] First, by comparing the total output power and load power of each phase, it can be determined that the locked phase is phase L3, and phases L1 and L2 are non-locked phases. Secondly, by comparing the three-phase total output power of each energy storage inverter and the discharge limit of the corresponding energy storage battery, it can be determined that the single-machine system B is a locked energy storage inverter and the single-machine system A is a non-locked energy storage inverter. Then, the difference between the load power corresponding to the lock and the sum of the initial allocated power of the non-locked energy storage inverters in the locked phase is calculated as the sum of the missing power. According to Table 5, the sum of the missing power is: 4-2=2, that is, the missing power required for phase L3 of the single-machine system B is 2.

[0141] Next, determine whether the initial power distribution of phases L1 and L2 in stand-alone system B is zero to determine the chargeable phase and remaining charge capacity. Table 5 shows that phase L2 in stand-alone system B is a chargeable phase with a remaining charge capacity of 2.

[0142] Next, the discharge margin is obtained based on the initial power distribution of phases L1 and L2 of the single-machine system A. According to Table 5, the discharge margin of phase L2 of the single-machine system A is 1.

[0143] Finally, based on the missing power, charge margin, and discharge margin, the target allocated power for each phase of each energy storage inverter is obtained. Following the power allocation process described in the above embodiment, the data in Table 6 is obtained: the corresponding allocated power for L3 of stand-alone system B is 1 (missing power), the corresponding reallocated power for L2 of stand-alone system A is 1 (first dispatched power), and the corresponding reallocated power for L2 of stand-alone system B is -1 (second dispatched power). Therefore, the target powers for each phase of stand-alone system B are 2, -1, and 1, respectively; and the target powers for each phase of stand-alone system A are 2, 2, and 2. Verification shows that the sum of the secondary allocated powers for each phase of stand-alone systems A and B does not exceed the total discharge limit of their respective batteries, and the secondary allocated power for each phase does not exceed the maximum allowable charge and discharge power for each phase. However, at this point, the total power of phase L3 is not equal to its corresponding load power. This means that after the secondary power allocation, the excess power in the inverter's energy storage battery is insufficient to fully compensate for the power shortfall. At this point, phase L3 needs to be supplied with another 1 from the grid, but this still reduces grid power consumption and saves costs.

[0144] Table 7 - Initial power distribution

[0145]

[0146] Table 8 - Secondary distribution power

[0147]

[0148] For Example 4, please refer to Tables 7 and 8, taking multiple locked energy storage inverters and one locked phase as an example. As shown in Table 7, it is known that the initial power distribution of each phase of single-machine system A is 2, 0, 2. The initial power distribution of each phase of single-machine system B is 2, 0, 0. The initial power distribution of each phase of single-machine system C is 2, 0, 2. The initial power distribution of each phase of single-machine system D is 2, 0, 0. The load power of L1, L2, and L3 is 8, 0, 6. The total battery discharge limit of single-machine systems A, B, C, and D is 6, 2, 6, and 2. Assume that the maximum allowable charge and discharge power of each phase is 2.

[0149] First, by comparing the total output power and load power of each phase, it can be determined that the locked phase is L3 phase, and phases L1 and L2 are non-locked phases. Secondly, by comparing the three-phase total output power of each energy storage inverter and the discharge limit of the corresponding energy storage battery, it can be determined that single-machine systems B and D are locked energy storage inverters, and single-machine systems A and C are non-locked energy storage inverters. Then, the difference between the load power corresponding to the lock and the sum of the initial distribution power of the non-locked energy storage inverters in the locked phase is calculated as the sum of the missing power. According to Table 7, the sum of the missing power is: 6-2-2=2, that is, the sum of the missing power required for the L3 phase of the single-machine systems B and D is 2. At this time, the equal division method can be used to determine that the missing power required for the L3 phase of the single-machine systems B and D is 1 respectively.

[0150] Next, determine whether the initial power distribution of phases L1 and L2 in stand-alone systems B and D is zero, thereby determining the chargeable phase and the remaining charge capacity. Table 7 shows that phase L2 in stand-alone systems B and D is a chargeable phase with a remaining charge capacity of 2.

[0151] Next, the discharge margin is obtained based on the initial power distribution of phases L1 and L2 of the stand-alone systems A and C. Table 7 shows that the discharge margin of phase L2 of the stand-alone systems A and C is 1.

[0152] Finally, based on the missing power, charge margin, and discharge margin, the target allocated power for each phase of each energy storage inverter is determined. Following the power allocation process described in the above embodiment, the data in Table 8 is obtained: the corresponding allocated power for L3 of stand-alone systems B and D is 1 (missing power), the corresponding reallocated power for L2 of stand-alone systems A and C is 1 (first dispatch power), and the corresponding reallocated power for L2 of stand-alone systems B and D is -1 (second dispatch power). This means that the target powers for each phase of stand-alone systems B and D are 2, -1, and 1, respectively; and the target powers for each phase of stand-alone systems A and C are 2, 1, and 2. Verification shows that the sum of the secondary allocated powers for each phase of stand-alone systems A through D does not exceed the total discharge limit of their respective batteries, the secondary allocated power for each phase does not exceed the maximum allowable charge and discharge power for each phase, and the overall power of each phase equals the corresponding load power. This means that after secondary power allocation, the excess power in the inverter's energy storage batteries not only compensates for the power shortfall but also provides a margin.

[0153] Table 9 - Initial power distribution

[0154]

[0155] Table 10 - Secondary distribution power

[0156]

[0157] For Example 5, please refer to Tables 9 and 10, taking multiple locked energy storage inverters and one locked phase as an example. As shown in Table 9, it is known that the initial power distribution of each phase of the single-machine system A is 2, 0, 2. The initial power distribution of each phase of the single-machine system B is 2, 0, 0. The initial power distribution of each phase of the single-machine system C is 2, 0, 2. The initial power distribution of each phase of the single-machine system D is 2, 0, 0. The load power of L1, L2, and L3 is 8, 0, and 6. The total battery discharge limit of the single-machine systems A, B, C, and D is 6, 2, 4, and 2. Assume that the maximum allowable charge and discharge power of each phase is 2.

[0158] First, by comparing the total output power of each phase with the load power, it can be determined that the locked phase is phase L3, and phases L1 and L2 are non-locked phases. Second, by comparing the three-phase total output power of each energy storage inverter with the discharge limit of the corresponding energy storage battery, it can be determined that single-machine systems B, C, and D are locked energy storage inverters, and single-machine system A is a non-locked energy storage inverter. It should be noted that although the three-phase total output power of single-machine system C is equal to the discharge limit of the corresponding energy storage battery, single-machine system C is set as a locked energy storage inverter. However, according to the unused margin of each locked energy storage inverter in the locked phase described above, the unused margin of phase L3 of single-machine system C is 0. Therefore, only power allocation for single-machine systems B and D needs to be considered. Then, the difference between the load power corresponding to the lock and the sum of the initially allocated powers of the non-locked energy storage inverters in the locked phase is calculated as the sum of the missing powers. According to Table 9, the sum of the missing powers is: 6-2-2=2, that is, the sum of the missing powers required for the L3 phase of the single-machine systems B and D is 2.

[0159] Next, determine whether the initial power distribution of phases L1 and L2 in stand-alone systems B and D is zero, thereby determining the chargeable phase and the remaining charge capacity. Table 9 shows that phase L2 in stand-alone systems B and D is a chargeable phase with a remaining charge capacity of 2.

[0160] Next, the discharge margin is calculated based on the initial power allocation for phases L1 and L2 of stand-alone system A. Table 9 shows that the discharge margin for phase L2 of stand-alone system A is 2. It's understandable that even if the discharge margin for phase L2 of stand-alone system A is 2, an additional 2 kW output still satisfies the total battery discharge limit for stand-alone system A.

[0161] Finally, based on the missing power, charge margin, and discharge margin, the target allocated power for each phase of each energy storage inverter is obtained. Following the power allocation process described in the above embodiment, the data in Table 10 is obtained: the corresponding allocated power for L3 of stand-alone system B is 2 (missing power), the corresponding reallocated power for L2 of stand-alone system A is 2 (first dispatch power), and the corresponding reallocated power for L2 of stand-alone system B is -2 (second dispatch power). That is, the target powers for each phase of stand-alone system B are 2, -2, and 2, respectively; the target powers for each phase of stand-alone system A are 2, 2, and 2; the target powers for each phase of stand-alone system C are 2, 0, and 2; and the target powers for each phase of stand-alone system D are 2, 0, and 0. Verification shows that the sum of the secondary allocated powers for each phase of stand-alone systems A through D does not exceed the total discharge limit of their respective batteries, the secondary allocated power for each phase does not exceed the maximum allowable charge and discharge power per phase, and the overall power of each phase equals the corresponding load power. In other words, after the secondary power allocation, the excess power in the inverter's energy storage batteries just compensates for the power shortfall.

[0162] The present embodiment provides a power allocation method for a three-phase parallel system. This method establishes a precise power scheduling foundation by acquiring current power demand information, including the load power, charge and discharge margin, and missing power of each phase. Subsequently, the target power of each phase is intelligently allocated based on the status of the energy storage inverter, ensuring that both the load demand is met and the energy storage device does not exceed the discharge or charge limits. Finally, power output is executed, and combined with real-time monitoring and feedback adjustment, the system can quickly respond to load changes and maintain grid stability. This solves the problems of inter-phase power rigidity and single-point bottlenecks that restrict overall performance in traditional parallel systems, significantly improving the load adaptability and operational reliability of the parallel system. Furthermore, the safety of the energy storage inverter is ensured, overload discharge or overcharging is avoided, and the equipment life is extended. Finally, through an intelligent power management mechanism, the distributed energy system can participate in grid scheduling more efficiently, with good economic efficiency, security, and scalability, and is suitable for a variety of energy storage and load scenarios.

[0163] Based on the power distribution method provided in the above embodiment, the present application embodiment further provides a power distribution device. Figure 4 , Figure 4 This is a schematic block diagram of the structure of the power distribution device. Figure 4 As shown, the power distribution device 200 includes: an acquisition module 210, a first confirmation module 220, a second confirmation module 230, a missing power calculation module 240, a charging margin calculation module 250, a discharging margin calculation module 260, a power scheduling calculation module 270 and a power distribution module 280. Among them, the acquisition module 210 is used to obtain the initial distribution power of each phase of each energy storage inverter; the first confirmation module 220 is used to determine the locked phase according to the initial distribution power of each phase of each energy storage inverter; the second confirmation module 230 is used to determine the locked energy storage inverter and the non-locked energy storage inverter according to the initial distribution power of each phase of each energy storage inverter and the discharge limit of the energy storage battery corresponding to each energy storage inverter; the missing power calculation module 240 is used to determine the missing of the locked phase of the locked energy storage inverter according to the locked energy storage inverter and the locked phase. Power; the charging margin calculation module 250 is used to obtain the charging margin based on the initial allocated power of the non-locked phase of the locked energy storage inverter; the discharging margin calculation module 260 is used to obtain the discharging margin based on the initial allocated power of the non-locked phase of the non-locked energy storage inverter; the power scheduling calculation module 270 is used to obtain the target allocated power of each phase of each energy storage inverter based on the missing power, the charging margin and the discharging margin; the power allocation module 280 is used to output power to match the load based on the target allocated power of each phase of each energy storage inverter.

[0164] It should be noted that the above-mentioned power distribution device can execute the power distribution method provided in the embodiment of the present application, and has the functional modules and beneficial effects corresponding to the execution method. For technical details not fully described in the embodiment of the power distribution device, please refer to the power distribution method provided in the embodiment of the present application.

[0165] The present application also provides a three-phase parallel system. Figure 5 , which shows the hardware structure of a three-phase parallel system capable of executing the method described in the above embodiment. The three-phase parallel system 300 includes: at least one processor 310; and a memory 320 in communication with the at least one processor 310. Figure 5 In the embodiment, a processor 310 is used as an example. The memory 320 stores instructions that can be executed by the at least one processor 310. The instructions are executed by the at least one processor 310 so that the at least one processor 310 can perform the power allocation method described in the above embodiment. The processor 310 and the memory 320 can be connected via a bus or other means. Figure 5 The bus connection is taken as an example.

[0166] Memory 320, as a non-volatile computer-readable storage medium, can be used to store non-volatile software programs, non-volatile computer-executable programs, and modules, such as the program instructions / modules corresponding to the power allocation method in the embodiments of the present application. Processor 310 executes the non-volatile software programs, instructions, and modules stored in memory 320 to execute various functional applications and data processing of the server, thereby implementing the power allocation method described in the above embodiments.

[0167] The memory 320 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and application programs required for at least one function; the data storage area may store data created based on the use of the computing device, etc. In addition, the memory 320 may include a high-speed random access memory and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some embodiments, the memory 320 may optionally include a memory remotely located relative to the processor 310, and these remote memories may be connected to the computing device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0168] The one or more modules are stored in the memory 320 , and when executed by the one or more processors 310 , perform the power allocation method described in the above embodiment.

[0169] The above-mentioned product can execute the method provided in the embodiment of this application, and has the functional modules and beneficial effects corresponding to the execution method. For technical details not fully described in this embodiment, please refer to the power allocation method described in any embodiment of this application.

[0170] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of this embodiment.

[0171] Through the description of the above embodiments, it is clear to those skilled in the art that each embodiment can be implemented by means of software plus a general hardware platform, or of course, by hardware. It is understood by those skilled in the art that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. The program can be stored in a computer-readable storage medium, and when the program is executed, it can include the processes of the embodiments of the above-mentioned methods. The storage medium can be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM).

[0172] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Based on the idea of the present application, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations in different aspects of the present application as above, which are not provided in detail for the sake of simplicity. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A power distribution method for a three-phase parallel system, wherein the three-phase parallel system includes at least two energy storage inverters, characterized in that: The method comprises: Obtaining the corresponding load power and the initial distribution power of each phase of each energy storage inverter; Calculating the total output power of each phase and the three-phase total output power of each energy storage inverter according to the initially distributed power of each phase of each energy storage inverter; Compare the total output power of each phase with the corresponding load power; define the phase whose total output power is less than the corresponding load power as a locked phase; otherwise, it is a non-locked phase; An energy storage inverter whose three-phase total output power is equal to the discharge limit of the energy storage battery is defined as a locked energy storage inverter; an energy storage inverter whose three-phase total output power is less than the discharge limit of the energy storage battery is defined as a non-locked energy storage inverter; Determining the missing power of the locked phase of the locked energy storage inverter according to the locked energy storage inverter and the locked phase; Determining the initial allocated power of the non-locked phase of the locked energy storage inverter to determine a chargeable phase, and obtaining the maximum allowable charging power of the chargeable phase in the locked energy storage inverter as a charging margin; Obtaining a discharge limit value of the energy storage battery corresponding to the non-locked energy storage inverter and a maximum allowable discharge power of the non-locked phase of the non-locked energy storage inverter; Calculating the discharge margin according to the discharge limit of the energy storage battery corresponding to the non-locked energy storage inverter, the maximum allowable discharge power of the non-locked phase of the non-locked energy storage inverter, and the initial allocated power; Obtaining a target allocated power for each phase of each energy storage inverter according to the missing power, the charging margin, and the discharging margin; According to the target distributed power of each phase of each energy storage inverter, power output is performed to match the load.

2. The power distribution method according to claim 1, wherein: The determining, based on the locked energy storage inverter and the locked phase, the missing power of the locked phase of the locked energy storage inverter includes: Obtaining the sum of the initially allocated powers of the non-locked energy storage inverters in the locked phase; The difference between the load power corresponding to the locking and the sum of the initial allocated powers of the non-locked energy storage inverters in the locking phase is the sum of the missing powers; The missing power of the locked phase of each locked energy storage inverter is determined according to the sum of the missing power, the number of the locked energy storage inverters and the maximum allowable discharge power.

3. The power distribution method according to claim 1, wherein: The determining of the initial allocated power of the non-locked phase of the locked energy storage inverter to determine a chargeable phase, and obtaining the maximum allowable charging power of the chargeable phase in the locked energy storage inverter as a charging margin, includes: Determining whether the initial distribution power of the non-locked phase in the locked energy storage inverter is zero; If the initially allocated power of the non-locked phase is not zero, it indicates that the non-locked phase is used to supply power to the load, and it is determined that the non-locked phase cannot perform a charging operation; If the initially allocated power of the non-locked phase is zero, it indicates that the non-locked phase is not used to power the load, and the non-locked phase is determined to be a chargeable phase; The maximum allowable charging power of the chargeable phase in the locked energy storage inverter is obtained as the charging margin.

4. The power distribution method according to claim 1, wherein: Obtaining the target allocated power of each phase of each energy storage inverter according to the missing power, the charging margin, and the discharging margin includes: Determine, according to the discharge margin and the missing power, a non-locked phase for power scheduling in the non-locked energy storage inverter, and obtain a first scheduling power of the non-locked phase for power scheduling in the non-locked energy storage inverter; Determine, according to the charge margin and the missing power, a non-locked phase for the power scheduling in the locked energy storage inverter, and obtain a second scheduling power of the non-locked phase for the power scheduling in the locked energy storage inverter; A target allocated power of each phase of each energy storage inverter is obtained according to the missing power, the first dispatching power, and the second dispatching power.

5. The power distribution method according to claim 4, characterized in that: The determining, based on the charge margin and the missing power, a non-locked phase for the power scheduling in the locked energy storage inverter, and obtaining a second scheduling power of the non-locked phase for the power scheduling in the locked energy storage inverter includes: Obtaining the load power corresponding to the non-locked state used for the power scheduling in the locked energy storage inverter and the discharge limit value of the energy storage battery corresponding to the non-locked energy storage inverter; The second scheduling power is obtained according to the first scheduling power, the load power and the discharge limit of the energy storage battery.

6. A power distribution device for a three-phase parallel system, the three-phase parallel system comprising at least two energy storage inverters, characterized in that: The device comprises: A first acquisition module, configured to acquire the corresponding load power and the initial allocated power of each phase of each energy storage inverter; a second acquisition module, configured to calculate the total output power of each phase and the three-phase total output power of each energy storage inverter based on the initial allocated power of each phase of each energy storage inverter; a first confirmation module, configured to compare the total output power of each phase with the corresponding load power; defining a phase whose total output power is less than the corresponding load power as a locked phase; otherwise, a phase whose total output power is less than the corresponding load power is a non-locked phase; a second confirmation module, configured to define an energy storage inverter whose three-phase total output power is equal to the discharge limit of the energy storage battery as a locked energy storage inverter; and define an energy storage inverter whose three-phase total output power is less than the discharge limit of the energy storage battery as a non-locked energy storage inverter; A missing power calculation module, the missing power calculation module is used to determine the missing power of the locked phase of the locked energy storage inverter according to the locked energy storage inverter and the locked phase; a charging remainder calculation module, the charging remainder calculation module being configured to determine the initial allocated power of the non-locked phase of the locked energy storage inverter to determine a chargeable phase, and to obtain the maximum allowable charging power of the chargeable phase in the locked energy storage inverter as the charging remainder; a third acquisition module, configured to acquire a discharge limit value of the energy storage battery corresponding to the non-locked energy storage inverter and a maximum allowable discharge power of the non-locked phase of the non-locked energy storage inverter; A discharge margin calculation module, configured to calculate the discharge margin based on the discharge limit of the energy storage battery corresponding to the non-locked energy storage inverter, the maximum allowable discharge power of the non-locked phase of the non-locked energy storage inverter, and the initial allocated power; A power scheduling calculation module, configured to obtain a target allocated power for each phase of each energy storage inverter according to the missing power, the charge margin, and the discharge margin; A power distribution module is used to distribute power according to the target of each phase of each energy storage inverter and output power to match the load.

7. A three-phase parallel system, characterized in that: include: at least one processor; as well as, a memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the method according to any one of claims 1 to 5.

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