Off-grid micro-grid network type energy storage balancing control method and system

Abstract

The present application belongs to the field of micro-grid energy storage unit control, and particularly relates to a network type energy storage balancing control method and system for off-grid micro-grid. The method comprises: if at least one energy storage unit SOC is lower than the emergency lower limit and is still discharging, and no other energy storage unit SOC exceeds the emergency upper limit and is still charging, among each network type energy storage unit of the off-grid micro-grid, taking the energy storage unit lower than the emergency lower limit and still discharging as a compensation required energy storage unit, and adjusting it downward one by one; taking the power of each compensation required energy storage unit adjusted downward each time as a first compensation required power, and distributing it to a first to-be-distributed energy storage unit; the first to-be-distributed energy storage unit is all energy storage units with SOC higher than the economic lower limit; the first compensation required power is distributed according to the proportion of the SOC of each energy storage unit in the sum of the SOCs of all to-be-distributed energy storage units, and the larger the proportion, the more it is distributed; if there is no first to-be-distributed energy storage unit, the adjustment is ended; the emergency lower limit is smaller than the economic lower limit.

Description

Technical Field

[0001] This invention belongs to the field of microgrid energy storage unit control, specifically relating to a grid-based energy storage equalization control method and system for off-grid microgrids. Background Technology

[0002] Currently, the efficient development and utilization of renewable energy (wind power, solar power, etc.) has become a core path for the green and low-carbon transformation of energy. Off-grid microgrids, as an important carrier for high-altitude, remote areas without grid coverage and for the local consumption of renewable energy, effectively solve problems such as insufficient coverage of traditional grids, power supply difficulties in remote areas, and obstacles to the consumption of new energy sources due to their flexible grid construction methods. They have been widely used in scenarios such as high-altitude pastoral areas, remote villages, and isolated island power supply. Among them, energy storage systems, as the key core for the efficient conversion and storage of renewable energy in off-grid microgrids, realize a closed loop of renewable energy "generation-storage-use" by accepting wind and solar power generation energy and smoothing power fluctuations. This provides a stable and reliable power supply solution for high-altitude and remote areas and has become an important support for the large-scale development of off-grid microgrids.

[0003] The stable and efficient operation of off-grid microgrids heavily relies on the support of energy storage systems, especially multi-grid energy storage systems (such as the synergistic use of multiple types of energy storage, including lithium batteries, flywheel energy storage, and hydrogen energy storage, or a grid cluster composed of multiple energy storage units). These systems not only serve as energy buffers and storage for renewable energy generation but also play a crucial role in grid support, maintaining voltage and frequency stability in the off-grid microgrid and ensuring continuous and reliable power supply for production, daily life, and emergency power needs in high-altitude and remote areas. However, off-grid microgrids lack the support and dispatch compensation of a large power grid. Coupled with the inherent randomness and volatility of wind and solar power generation, as well as the dynamic changes in electricity load in remote areas, multi-grid energy storage systems face severe energy imbalance problems. Among these, the imbalance of SOC (State of Charge) among multiple energy storage units is one of the core pain points.

[0004] In multi-grid energy storage systems, the charging and discharging characteristics, capacity parameters, and response speeds of different types of energy storage units (or different modules of the same type) vary significantly. Furthermore, influenced by fluctuations in wind and solar power generation and changes in electricity load demand in remote areas, the State of Charge (SOC) of each energy storage unit is prone to divergence. Some units may experience excessively high SOC due to overcharging, facing the risk of overcharge damage and lifespan reduction; others may experience excessively low SOC due to over-discharging, failing to meet grid support and energy supply requirements, and even causing system failure. This, in turn, affects the stable operation of off-grid microgrids and restricts the continuity and reliability of power supply to high-altitude and remote areas. Moreover, existing technologies lack a dynamic equilibrium control mechanism adapted to multi-grid energy storage systems. They cannot achieve precise energy allocation and dynamic equilibrium based on the SOC state, charging and discharging characteristics of each energy storage unit, and the operating conditions of the microgrid, making it difficult to meet the multiple requirements of stable operation, efficient energy storage, and reliable power supply for off-grid microgrids.

[0005] Chinese invention patent application CN108649593A discloses a coordinated control method for multiple energy storage units based on state of charge (SOC) in a DC microgrid. The DC microgrid includes a photovoltaic system, loads, and an energy storage system connected to a DC bus via converters. The energy storage system comprises multiple energy storage units. The method includes: when the voltage of the DC bus in the DC microgrid fluctuates, maintaining the voltage stability of the DC bus by controlling the total output power of the energy storage system. Each energy storage unit in the energy storage system allocates its output power according to its own SOC. Compared with existing technologies, this invention, by dynamically adjusting the charging and discharging power of each energy storage unit, can ensure SOC balance among the energy storage units, maintain the stability of the bus voltage, and prevent overcharging or over-discharging of the energy storage units, thus extending their lifespan. It has advantages such as simplicity, good scalability, and strong robustness, and is easy to implement in practical systems. However, this scheme requires the participation of many energy storage units in coordinated control, which may lead to excessively frequent adjustments and make it difficult to meet the stable operation requirements of off-grid microgrids. Summary of the Invention

[0006] The purpose of this invention is to provide a grid-based energy storage equalization control method and system for off-grid microgrids, which solves the problem that grid-based energy storage units in off-grid microgrids may adjust too frequently in the prior art, making it difficult to meet the stable operation requirements of off-grid microgrids.

[0007] To achieve the above objectives, the first aspect of the present invention provides a grid-based energy storage balancing control method for off-grid microgrids, comprising:

[0008] If, in each grid-type energy storage unit of an off-grid microgrid, there is at least one energy storage unit whose SOC is below the emergency lower limit and is still discharging, and no other energy storage unit whose SOC is above the emergency upper limit and is still charging, then the energy storage unit that is discharging below the emergency lower limit is the one that needs compensation, and the energy storage units are adjusted downward one by one.

[0009] The first compensation power is allocated to the first energy storage units to be allocated, with the power reduction of each energy storage unit required for compensation each time being the first compensation power. The first energy storage units to be allocated are all energy storage units with a State of Charge (SOC) higher than the economic minimum. The first compensation power is allocated according to the ratio of the SOC of each energy storage unit to the sum of the SOCs of all energy storage units to be allocated, with a larger ratio resulting in more units being allocated. If, after the allocated compensation power is added, there is an energy storage unit to be allocated that exceeds the maximum charging power, then that energy storage unit is removed from the first energy storage units to be allocated, and the first compensation power is redistributed to the remaining energy storage units to be allocated. If there is no energy storage unit to be allocated, the adjustment ends.

[0010] The emergency floor is less than the economic floor.

[0011] The first aspect of this invention provides a grid-based energy storage balancing control method for off-grid microgrids, which, in one possible implementation, further includes:

[0012] If, in each grid-type energy storage unit of an off-grid microgrid, there is at least one energy storage unit whose SOC exceeds the emergency upper limit and is still charging, and no other energy storage unit whose SOC is below the emergency lower limit and is still discharging, then the energy storage unit that exceeds the emergency upper limit and is still charging is the energy storage unit that needs compensation, and the compensation is adjusted upwards one by one.

[0013] The second compensation power is allocated to the second energy storage units to be allocated, with each increase in power of the energy storage unit requiring compensation being the second compensation power. The second energy storage units to be allocated are all energy storage units with a State of Charge (SOC) below the economic limit. The second compensation power is allocated according to the ratio of the discharge depth of each energy storage unit to the sum of the discharge depths of all energy storage units to be allocated; the larger the ratio, the more is allocated. If, after the allocated compensation power is added, there is a second energy storage unit to be allocated that exceeds the maximum discharge power, then that energy storage unit is removed from the second energy storage units to be allocated, and the second compensation power is redistributed to the remaining second energy storage units to be allocated. If there are no second energy storage units to be allocated, the adjustment ends.

[0014] The emergency cap is greater than the economic cap.

[0015] The first aspect of this invention provides a grid-based energy storage balancing control method for off-grid microgrids, which, in one possible implementation, further includes:

[0016] If, in an off-grid microgrid, at least one energy storage unit has a State of Charge (SOC) below the emergency lower limit while still discharging, and at least one energy storage unit has a SOC above the emergency upper limit while still charging, resulting in improper circulating current among the energy storage units, then the two energy storage units with the highest current discharge power and the highest current charging power are selected. Under total power discharge conditions, the energy storage units with the highest discharge and charging power allocate the adjustment target according to the proportion of their own SOC to the sum of their own and the other's SOCs; the larger the proportion, the larger the proportion of the allocated adjustment target. Under total power charging conditions, the energy storage units with the highest discharge and charging power allocate the adjustment target according to the proportion of their own discharge depth to the sum of their own and the other's discharge depths; the larger the proportion, the larger the proportion of the allocated adjustment target. The adjustment target is determined based on the combined power of the two energy storage units to be adjusted. After adjustment, the two energy storage units with the highest current discharge and charging power are reselected, and adjustment continues until improper circulating current is eliminated.

[0017] The first aspect of this invention provides a grid-based energy storage balancing control method for off-grid microgrids, which, in one possible implementation, further includes:

[0018] If all grid-type energy storage units in an off-grid microgrid are in a discharging state, the minimum SOC of an energy storage unit is below the economic minimum limit, the difference between the maximum and minimum SOC of an energy storage unit is greater than the economic minimum limit of a first set proportion, and the discharge power of the energy storage unit with the maximum SOC is less than the discharge power of the energy storage unit with the minimum SOC, then the power regulation targets for the maximum and minimum SOC energy storage units are allocated according to the proportion of their own SOC to the sum of their own and the other's SOC. The larger the proportion, the larger the proportion of the allocated regulation target. The regulation target is determined based on the combined power of the two energy storage units to be regulated.

[0019] The first aspect of this invention provides a grid-based energy storage balancing control method for off-grid microgrids, which, in one possible implementation, further includes:

[0020] If all grid-type energy storage units in an off-grid microgrid are in a charging state, the largest energy storage unit's SOC is higher than the economic upper limit, the difference between the largest and smallest energy storage units' SOC is greater than the second set proportion of the economic upper limit, and the charging power of the energy storage unit with the largest SOC is greater than the charging power of the energy storage unit with the smallest SOC, then the power regulation targets for the largest and smallest SOC energy storage units are allocated according to the proportion of their own discharge depth to the sum of their own and the other's discharge depths. The larger the proportion, the larger the proportion of the allocated regulation target. The regulation target is determined based on the combined power of the two energy storage units to be regulated.

[0021] The first aspect of the present invention provides a grid-based energy storage equalization control method for off-grid microgrids. In one possible implementation, when each energy storage unit requiring compensation is adjusted upwards, the adjustment is carried out in order from the furthest to the nearest time since the last control.

[0022] The first aspect of the present invention provides a grid-based energy storage balancing control method for off-grid microgrids. In one possible implementation, when each energy storage unit requiring compensation is adjusted downwards, the adjustment is carried out in order from the furthest to the nearest time since the last control.

[0023] The first aspect of this invention provides a grid-connected energy storage balancing control method for off-grid microgrids. In one possible implementation, the method for determining whether the power regulation of the current energy storage unit requiring compensation has been completed includes:

[0024] If the power of the energy storage unit that needs compensation has been adjusted to within the set power control dead zone, the determination bit completes the power adjustment of the energy storage unit that needs compensation; the actual power of the energy storage unit within the set power control dead zone is 0.

[0025] The first aspect of this invention provides a grid-based energy storage balancing control method for off-grid microgrids. In one possible implementation, the adjustment amount of each energy storage unit requiring compensation does not exceed a set step size until the power regulation of the current energy storage unit requiring compensation is completed.

[0026] The above-described technical solution of the present invention provides a novel grid-based energy storage balancing control method for off-grid microgrids, the beneficial effects of which include:

[0027] Based on the setting of emergency and economic upper and lower limits, specifically targeting each grid-type energy storage unit in off-grid microgrids, there is a situation where at least one energy storage unit is discharging below the emergency lower limit, and no other energy storage unit is charging above the emergency upper limit. In other words, there is an energy imbalance where some energy storage units are over-discharged and there is no overcharging. By controlling the SOC between the emergency upper and lower limits, overcharging and over-discharging of energy storage can be avoided, effectively extending the life of energy storage.

[0028] A second aspect of the present invention provides a grid-based energy storage balancing control system for an off-grid microgrid, comprising a memory, a processor, and a computer program stored in the memory. The processor executes the computer program to implement the following steps of a grid-based energy storage balancing control method for an off-grid microgrid, specifically including:

[0029] If, in each grid-type energy storage unit of an off-grid microgrid, there is at least one energy storage unit whose SOC is below the emergency lower limit and is still discharging, and no other energy storage unit whose SOC is above the emergency upper limit and is still charging, then the energy storage unit that is discharging below the emergency lower limit is the one that needs compensation, and the energy storage units are adjusted downward one by one.

[0030] The first compensation power is allocated to the first energy storage units to be allocated, with the power reduction of each energy storage unit required for compensation each time being the first compensation power. The first energy storage units to be allocated are all energy storage units with a State of Charge (SOC) higher than the economic minimum. The first compensation power is allocated according to the ratio of the SOC of each energy storage unit to the sum of the SOCs of all energy storage units to be allocated, with a larger ratio resulting in more units being allocated. If, after the allocated compensation power is added, there is an energy storage unit to be allocated that exceeds the maximum charging power, then that energy storage unit is removed from the first energy storage units to be allocated, and the first compensation power is redistributed to the remaining energy storage units to be allocated. If there is no energy storage unit to be allocated, the adjustment ends.

[0031] The emergency floor is less than the economic floor.

[0032] The second aspect of the present invention provides a grid-connected energy storage balancing control system for an off-grid microgrid, which, in one possible implementation, further includes:

[0033] If, in each grid-type energy storage unit of an off-grid microgrid, there is at least one energy storage unit whose SOC exceeds the emergency upper limit and is still charging, and no other energy storage unit whose SOC is below the emergency lower limit and is still discharging, then the energy storage unit that exceeds the emergency upper limit and is still charging is the energy storage unit that needs compensation, and the compensation is adjusted upwards one by one.

[0034] The second compensation power is allocated to the second energy storage units to be allocated, with each increase in power of the energy storage unit requiring compensation being the second compensation power. The second energy storage units to be allocated are all energy storage units with a State of Charge (SOC) below the economic limit. The second compensation power is allocated according to the ratio of the discharge depth of each energy storage unit to the sum of the discharge depths of all energy storage units to be allocated; the larger the ratio, the more is allocated. If, after the allocated compensation power is added, there is a second energy storage unit to be allocated that exceeds the maximum discharge power, then that energy storage unit is removed from the second energy storage units to be allocated, and the second compensation power is redistributed to the remaining second energy storage units to be allocated. If there are no second energy storage units to be allocated, the adjustment ends.

[0035] The emergency cap is greater than the economic cap.

[0036] The second aspect of the present invention provides a grid-connected energy storage balancing control system for an off-grid microgrid, which, in one possible implementation, further includes:

[0037] If, in an off-grid microgrid, at least one energy storage unit has a State of Charge (SOC) below the emergency lower limit while still discharging, and at least one energy storage unit has a SOC above the emergency upper limit while still charging, resulting in improper circulating current among the energy storage units, then the two energy storage units with the highest current discharge power and the highest current charging power are selected. Under total power discharge conditions, the energy storage units with the highest discharge and charging power allocate the adjustment target according to the proportion of their own SOC to the sum of their own and the other's SOCs; the larger the proportion, the larger the proportion of the allocated adjustment target. Under total power charging conditions, the energy storage units with the highest discharge and charging power allocate the adjustment target according to the proportion of their own discharge depth to the sum of their own and the other's discharge depths; the larger the proportion, the larger the proportion of the allocated adjustment target. The adjustment target is determined based on the combined power of the two energy storage units to be adjusted. After adjustment, the two energy storage units with the highest current discharge and charging power are reselected, and adjustment continues until improper circulating current is eliminated.

[0038] The second aspect of the present invention provides a grid-connected energy storage balancing control system for an off-grid microgrid, which, in one possible implementation, further includes:

[0039] If all grid-type energy storage units in an off-grid microgrid are in a discharging state, the minimum SOC of an energy storage unit is below the economic minimum limit, the difference between the maximum and minimum SOC of an energy storage unit is greater than the economic minimum limit of a first set proportion, and the discharge power of the energy storage unit with the maximum SOC is less than the discharge power of the energy storage unit with the minimum SOC, then the power regulation targets for the maximum and minimum SOC energy storage units are allocated according to the proportion of their own SOC to the sum of their own and the other's SOC. The larger the proportion, the larger the proportion of the allocated regulation target. The regulation target is determined based on the combined power of the two energy storage units to be regulated.

[0040] The second aspect of the present invention provides a grid-connected energy storage balancing control system for an off-grid microgrid, which, in one possible implementation, further includes:

[0041] If all grid-type energy storage units in an off-grid microgrid are in a charging state, the largest energy storage unit's SOC is higher than the economic upper limit, the difference between the largest and smallest energy storage units' SOC is greater than the second set proportion of the economic upper limit, and the charging power of the energy storage unit with the largest SOC is greater than the charging power of the energy storage unit with the smallest SOC, then the power regulation targets for the largest and smallest SOC energy storage units are allocated according to the proportion of their own discharge depth to the sum of their own and the other's discharge depths. The larger the proportion, the larger the proportion of the allocated regulation target. The regulation target is determined based on the combined power of the two energy storage units to be regulated.

[0042] The second aspect of the present invention provides a grid-type energy storage balancing control system for an off-grid microgrid. In one possible implementation, when each energy storage unit requiring compensation is adjusted upwards, the adjustments are made sequentially from the earliest to the latest time since the last control.

[0043] The second aspect of the present invention provides a grid-type energy storage balancing control system for an off-grid microgrid. In one possible implementation, when each energy storage unit requiring compensation is adjusted downwards, the units are adjusted one by one in order from the furthest to the nearest time since the last control.

[0044] The second aspect of this invention provides a grid-connected energy storage balancing control system for an off-grid microgrid. In one possible implementation, the method for determining whether the power regulation of the current energy storage unit requiring compensation has been completed includes:

[0045] If the power of the energy storage unit that needs compensation has been adjusted to within the set power control dead zone, the determination bit completes the power adjustment of the energy storage unit that needs compensation; the actual power of the energy storage unit within the set power control dead zone is 0.

[0046] The second aspect of the present invention provides a grid-based energy storage equalization control system for an off-grid microgrid. In one possible implementation, the adjustment amount of each energy storage unit requiring compensation does not exceed a set step size until the power adjustment of the current energy storage unit requiring compensation is completed.

[0047] The technical solution of the off-grid microgrid grid-based energy storage equalization control system described above can achieve the same beneficial effects as the off-grid microgrid grid-based energy storage equalization control method described above. Attached Figure Description

[0048] Figure 1 These are example diagrams of the architecture of an off-grid microgrid in the first, second, third, fourth, and fifth embodiments of the grid-based energy storage equalization control method for off-grid microgrids of the present invention.

[0049] Figure 2 This is a flowchart of the grid-based energy storage equalization control method for off-grid microgrids in the first embodiment of the present invention.

[0050] Figure 3 This is a flowchart of the grid-based energy storage balance control method for off-grid microgrids in the second embodiment of the present invention.

[0051] Figure 4 This is a flowchart of the grid-based energy storage balance control method for off-grid microgrids in the third embodiment of the present invention.

[0052] Figure 5 This is a flowchart of the grid-based energy storage equalization control method for off-grid microgrids in the fourth embodiment of the present invention.

[0053] Figure 6 This is a flowchart of the grid-based energy storage equalization control method for off-grid microgrids in the fifth embodiment of the present invention.

[0054] Figure 7 These are structural example diagrams of the grid-based energy storage equalization control system for off-grid microgrids in the first, second, third, fourth, and fifth embodiments of the present invention. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0056] Figure 1 This invention relates to an off-grid microgrid, primarily comprising photovoltaic (PV) systems, energy storage stations, diesel generators, and loads. Addressing the issue of energy imbalance across multiple state-of-the-art (SOC) states in multi-grid energy storage systems within off-grid microgrids, the invention considers the SOC state of the multi-grid energy storage systems. Based on principles such as maintaining a reasonable SOC state and avoiding circulating current SOC imbalance, it achieves precise control and autonomous balancing of the multi-grid off-grid energy storage system. The off-grid microgrid energy storage balancing control method and the strategy adjustments in various system implementations are based on this off-grid microgrid architecture, preventing the activation of voltage fluctuation suppression strategies, and these strategies are secondary adjustments.

[0057] Specifically, for ease of explanation, we will refer to the i-th energy storage unit, i.e. #Energy Storage (where N is the total number of grid-connected energy storage units in the off-grid microgrid), and the discharge power is denoted as . The constraints (each energy storage unit's constraints are independent) are: ,in (Specifically, negative values) are #Maximum discharge power of energy storage (Specifically, positive values) are #Maximum charging power of energy storage; that is, each energy storage unit must not exceed the maximum charging and discharging power of energy storage.

[0058] First Implementation Method of Grid-Based Energy Storage Balance Control Method for Off-Grid Microgrids

[0059] This embodiment presents a technical solution for a grid-based energy storage balancing control method in an off-grid microgrid. Based on setting emergency upper and lower limits, it specifically addresses the situation where, in each grid-based energy storage unit of the off-grid microgrid, at least one energy storage unit is discharging even when its SOC is below the emergency lower limit, while no other energy storage unit is charging even when its SOC is above the emergency upper limit. This indicates an energy imbalance where some energy storage units are over-discharged but there is no overcharging. By controlling the SOC between the emergency upper and lower limits, overcharging and over-discharging of the energy storage are avoided, effectively extending the energy storage life.

[0060] The method includes:

[0061] If, in each grid-type energy storage unit of an off-grid microgrid, there is at least one energy storage unit whose SOC is below the emergency lower limit and is still discharging, and no other energy storage unit whose SOC is above the emergency upper limit and is still charging, then the energy storage unit that is discharging below the emergency lower limit is the one that needs compensation, and the energy storage units are adjusted downward one by one.

[0062] The first compensation power is allocated to the first energy storage units to be allocated, with the power reduction of each energy storage unit required for compensation each time being the first compensation power. The first energy storage units to be allocated are all energy storage units with a State of Charge (SOC) higher than the economic minimum. The first compensation power is allocated according to the ratio of the SOC of each energy storage unit to the sum of the SOCs of all energy storage units to be allocated, with a larger ratio resulting in more units being allocated. If, after the allocated compensation power is added, there is an energy storage unit to be allocated that exceeds the maximum charging power, then that energy storage unit is removed from the first energy storage units to be allocated, and the first compensation power is redistributed to the remaining energy storage units to be allocated. If there is no energy storage unit to be allocated, the adjustment ends.

[0063] Specifically, the emergency floor is lower than the economic floor.

[0064] Therefore, this method addresses the energy imbalance situation where some energy storage units are over-discharged but not overcharged. It fully considers SOC control, maintaining the SOC between the emergency upper and lower limits to prevent overcharging and over-discharging, effectively extending the energy storage lifespan. The power reduction for over-discharged energy storage units is achieved by evenly distributing the power only to units whose SOC does not exceed the economic upper and lower limits. This unifies energy storage SOC balance control, off-grid microgrid stable operation, and reliable power supply in remote areas within a single control framework. While maximizing renewable energy absorption and ensuring the safe and stable operation of the energy storage system, it strictly ensures that the SOC of each energy storage unit does not fall below the emergency lower limit, meeting the grid support requirements of multi-grid energy storage systems. Simultaneously, it ensures that the SOC of each energy storage unit does not exceed the economic upper and lower limits, effectively avoiding the risks of overcharging damage and lifespan degradation, thus extending the lifespan of the energy storage system and reducing operation and maintenance costs. Its application scenarios are not limited to off-grid microgrids in high-altitude remote areas; it can also be extended to various off-grid scenarios without large-scale grid support, such as high-altitude pastoral areas, remote villages, and isolated island power supply, demonstrating broad applicability and outstanding practical value.

[0065] In this embodiment, each energy storage unit requiring compensation is adjusted upwards sequentially, following the order from oldest to youngest since the last control. This minimizes frequent adjustments to certain energy storage units, thereby extending their lifespan and ensuring the safe and stable operation of the energy storage system. In other embodiments, the energy storage units requiring compensation are adjusted upwards in a different order, such as by pre-defined numbers or according to importance.

[0066] In addition, during power regulation, the adjustment amplitude of a single energy storage unit requiring compensation is strictly limited to a set step size until the predetermined power regulation task is completed. The small-step gradual adjustment mode can prevent the single power regulation amplitude (i.e., the first power requiring compensation in a single operation) from being too large, resulting in an insufficient number of available energy storage units for power allocation, and can also effectively suppress large fluctuations in power and voltage in off-grid microgrids.

[0067] In one specific embodiment, the definition is... #The SOC of energy storage is And its range is Set an allowable upper limit for the State of Charge (SOC) of energy storage. The emergency limit is 0.9. The economic ceiling is 0.8. The lower limit of the economic curve is 0.7. The emergency lower limit is 0.3. The lower limit is 0.2. It is 0.1.

[0068] In this embodiment, among the grid-type energy storage units of the off-grid microgrid, there exists at least one energy storage unit whose SOC is below the emergency lower limit and is still discharging, while no other energy storage unit has an SOC above the emergency upper limit and is still charging; that is, there exists a non-empty subset. , so that: , And for other energy storage units: , .

[0069] First, adjust the grid-type energy storage units (i.e., grid-type energy storage units) that were last controlled a long time ago. Assuming... #Energy storage (of which) The primary regulating energy storage unit (i.e., the first energy storage unit requiring compensation) is adjusted in stages, with each adjustment not exceeding the step size, until its power reaches the upper limit of the energy storage's power control dead zone; each downward adjustment (i.e., the first power requiring compensation) is denoted as... Based on this, the specific allocation method is as follows:

[0070] All other grid-type energy storage systems with a SOC higher than the economic SOC lower limit are allocated power deviations based on SOC, assuming a aggregate... Set A is the set of grid-type energy storage units that will not exceed the maximum charging power of energy storage among all other grid-type energy storage units with SOC higher than the economic SOC lower limit, i.e. the set of the first energy storage units to be allocated;

[0071] Among them, for #Energy storage (of which) ,Right now (If the energy storage SOC is higher than the economic SOC lower limit, but the actual output does not exceed its maximum discharge power, the downward adjustment amount is...) This is equivalent to weighting the compensation power corresponding to the power reduction of the currently controlled energy storage unit according to the weight of each unit's SOC relative to the total SOC of all grid-connected energy storage units in set A. The higher the unit's SOC ratio, the greater the allocated compensation power (i.e., the higher the energy storage's SOC, the greater the downward adjustment it can withstand, and the stronger its external power support capability). If the charging power of the energy storage unit exceeds its own maximum charging power limit after the compensation power is added together (i.e., ...), If the set is empty, the unit is removed from set A and re-allocated within set A using the aforementioned allocation algorithm to complete the compensation power allocation; if set A is empty, the current power adjustment process is terminated prematurely. Finally, #Power regulation of the energy storage unit to its target value (wherein) That is, before adjustment (The energy storage SOC has fallen below the emergency lower limit, but discharge continues), meaning the power is adjusted to the upper limit of the energy storage power control dead zone, and the index subset of energy storage units requiring compensation is selected. The units within the unit perform adjustment operations sequentially until completion. Adjustments are made after the collection traversal ends.

[0072] Taking an off-grid microgrid containing three grid-connected energy storage units as an example, assuming that energy storage unit #1 meets the following requirements... Neither Energy Storage Unit 2 nor Energy Storage Unit 3 meets the requirements. Its flowchart is as follows Figure 2 As shown.

[0073] Furthermore, to avoid frequent switching of charging and discharging states by the energy storage unit near zero power, the methods for determining whether the power regulation of the current energy storage unit requiring compensation has been completed include:

[0074] If the power of the energy storage unit requiring compensation has been adjusted to within the set power control dead zone, the determination bit indicates that the power adjustment of the current energy storage unit requiring compensation is complete; the actual power of the energy storage unit within the set power control dead zone is 0. In one specific embodiment, the power control dead zone of the energy storage is set to ±5% of the rated power; that is, if the rated power of each energy storage unit is 100kW, then when the commanded power is between -5kW and +5kW, it is considered that the energy storage unit is within the set power control dead zone, and the actual power of the energy storage unit is 0. In other embodiments, the conditions for determining whether the power adjustment of the current energy storage unit requiring compensation is complete can also be flexibly set, such as adjusting the power of the current energy storage unit requiring compensation to a specified value or meeting a certain number of adjustment times.

[0075] The off-grid microgrid grid-based energy storage balancing control method in this embodiment establishes a dynamic regulation mechanism, taking into account both grid constraints and economic objectives. It achieves precise balancing control of multiple SOCs under multiple grid-based energy storage, while ensuring the stable operation of the off-grid microgrid and the reliability of power supply in remote areas. This promotes the large-scale application and high-quality development of off-grid microgrids in high-altitude and remote areas.

[0076] First Implementation Method of Grid-Based Energy Storage Balance Control System for Off-Grid Microgrids

[0077] This embodiment presents a technical solution for a grid-connected energy storage balancing control system for an off-grid microgrid, referring to... Figure 7 This includes a memory, a processor, and a computer program stored in the memory. The processor executes the computer program to implement the following steps of a grid-connected energy storage balancing control method for off-grid microgrids, specifically including:

[0078] If, in each grid-type energy storage unit of an off-grid microgrid, there is at least one energy storage unit whose SOC is below the emergency lower limit and is still discharging, and no other energy storage unit whose SOC is above the emergency upper limit and is still charging, then the energy storage unit that is discharging below the emergency lower limit is the one that needs compensation, and the energy storage units are adjusted downward one by one.

[0079] The first compensation power is allocated to the first energy storage units to be allocated, with the power reduction of each energy storage unit required for compensation each time being the first compensation power. The first energy storage units to be allocated are all energy storage units with a State of Charge (SOC) higher than the economic minimum. The first compensation power is allocated according to the ratio of the SOC of each energy storage unit to the sum of the SOCs of all energy storage units to be allocated, with a larger ratio resulting in more units being allocated. If, after the allocated compensation power is added, there is an energy storage unit to be allocated that exceeds the maximum charging power, then that energy storage unit is removed from the first energy storage units to be allocated, and the first compensation power is redistributed to the remaining energy storage units to be allocated. If there is no energy storage unit to be allocated, the adjustment ends.

[0080] Specifically, the emergency floor is lower than the economic floor.

[0081] Therefore, this system addresses the energy imbalance situation where some energy storage units are over-discharged but not overcharged. It fully considers SOC control, maintaining the SOC between the emergency upper and lower limits to prevent overcharging and over-discharging, effectively extending the energy storage lifespan. The power reduction for over-discharged energy storage units is balanced only among those with SOCs within the economic upper and lower limits. This unifies energy storage SOC balance control, off-grid microgrid stability, and reliable power supply in remote areas within a single control framework. While maximizing renewable energy absorption and ensuring the safe and stable operation of the energy storage system, it strictly ensures that the SOC of each energy storage unit does not fall below the emergency lower limit, meeting the grid support requirements for multi-grid energy storage systems. Simultaneously, it guarantees that the SOC of each energy storage unit does not exceed the economic upper and lower limits, effectively avoiding the risks of overcharging damage and lifespan degradation, thus extending the energy storage system's lifespan and reducing operation and maintenance costs. Its application scenarios are not limited to off-grid microgrids in high-altitude remote areas; it can also be extended to various off-grid scenarios without large-scale grid support, such as high-altitude pastoral areas, remote villages, and isolated island power supply, demonstrating broad applicability and outstanding practical value.

[0082] In this embodiment, each energy storage unit requiring compensation is adjusted upwards sequentially, following the order from oldest to youngest since the last control. This minimizes frequent adjustments to certain energy storage units, thereby extending their lifespan and ensuring the safe and stable operation of the energy storage system. In other embodiments, the energy storage units requiring compensation are adjusted upwards in a different order, such as by pre-defined numbers or according to importance.

[0083] In addition, during power regulation, the adjustment amplitude of a single energy storage unit requiring compensation is strictly limited to a set step size until the predetermined power regulation task is completed. The small-step gradual adjustment mode can prevent the single power regulation amplitude (i.e., the first power requiring compensation in a single operation) from being too large, resulting in an insufficient number of available energy storage units for power allocation, and can also effectively suppress large fluctuations in power and voltage in off-grid microgrids.

[0084] In one specific embodiment, the definition is... #The SOC of energy storage is And its range is Set an allowable upper limit for the State of Charge (SOC) of energy storage. The emergency limit is 0.9. The economic ceiling is 0.8. The lower limit of the economic curve is 0.7. The emergency lower limit is 0.3. The lower limit is 0.2. It is 0.1.

[0085] In this embodiment, among the grid-type energy storage units of the off-grid microgrid, there exists at least one energy storage unit whose SOC is below the emergency lower limit and is still discharging, while no other energy storage unit has an SOC above the emergency upper limit and is still charging; that is, there exists a non-empty subset. , so that: , And for other energy storage units: , .

[0086] First, adjust the grid-type energy storage units (i.e., grid-type energy storage units) that were last controlled a long time ago. Assuming... #Energy storage (of which) The primary regulating energy storage unit (i.e., the first energy storage unit requiring compensation) is adjusted in stages, with each adjustment not exceeding the step size, until its power reaches the upper limit of the energy storage's power control dead zone; each downward adjustment (i.e., the first power requiring compensation) is denoted as... Based on this, the specific allocation method is as follows:

[0087] All other grid-type energy storage systems with a SOC higher than the economic SOC lower limit are allocated power deviations based on SOC, assuming a aggregate... Set A is the set of grid-type energy storage units that will not exceed the maximum charging power of energy storage among all other grid-type energy storage units with SOC higher than the economic SOC lower limit, i.e. the set of the first energy storage units to be allocated;

[0088] Among them, for #Energy storage (of which) ,Right now (If the energy storage SOC is higher than the economic SOC lower limit, but the actual output does not exceed its maximum discharge power, the downward adjustment amount is...) This is equivalent to weighting the compensation power corresponding to the power reduction of the currently controlled energy storage unit according to the weight of each unit's SOC relative to the total SOC of all grid-connected energy storage units in set A. The higher the unit's SOC ratio, the greater the allocated compensation power (i.e., the higher the energy storage's SOC, the greater the downward adjustment it can withstand, and the stronger its external power support capability). If the charging power of the energy storage unit exceeds its own maximum charging power limit after the compensation power is added together (i.e., ...), If the set is empty, the unit is removed from set A and re-allocated within set A using the aforementioned allocation algorithm to complete the compensation power allocation; if set A is empty, the current power adjustment process is terminated prematurely. Finally, #Power regulation of the energy storage unit to its target value (wherein) That is, before adjustment (The energy storage SOC has fallen below the emergency lower limit, but discharge continues), meaning the power is adjusted to the upper limit of the energy storage power control dead zone, and the index subset of energy storage units requiring compensation is selected. The units within the unit perform adjustment operations sequentially until completion. Adjustments are made after the collection traversal ends.

[0089] Taking an off-grid microgrid containing three grid-connected energy storage units as an example, assuming that energy storage unit #1 meets the following requirements... Neither Energy Storage Unit 2 nor Energy Storage Unit 3 meets the requirements. .

[0090] Furthermore, to avoid frequent switching of charging and discharging states by the energy storage unit near zero power, the methods for determining whether the power regulation of the current energy storage unit requiring compensation has been completed include:

[0091] If the power of the energy storage unit requiring compensation has been adjusted to within the set power control dead zone, the determination bit indicates that the power adjustment of the current energy storage unit requiring compensation is complete; the actual power of the energy storage unit within the set power control dead zone is 0. In one specific embodiment, the power control dead zone of the energy storage is set to ±5% of the rated power; that is, if the rated power of each energy storage unit is 100kW, then when the commanded power is between -5kW and +5kW, it is considered that the energy storage unit is within the set power control dead zone, and the actual power of the energy storage unit is 0. In other embodiments, the conditions for determining whether the power adjustment of the current energy storage unit requiring compensation is complete can also be flexibly set, such as adjusting the power of the current energy storage unit requiring compensation to a specified value or meeting a certain number of adjustment times.

[0092] The off-grid microgrid grid-based energy storage equalization control system in this embodiment establishes a dynamic regulation mechanism, taking into account both grid constraints and economic objectives. This achieves precise equalization control of multiple SOCs under multiple grid-based energy storage systems, while ensuring the stable operation of the off-grid microgrid and the reliability of power supply in remote areas. This promotes the large-scale application and high-quality development of off-grid microgrids in high-altitude and remote areas.

[0093] Second Implementation Method of Grid-Based Energy Storage Balance Control Method for Off-Grid Microgrids

[0094] This embodiment presents a technical solution for a grid-based energy storage balancing control method in an off-grid microgrid. Based on setting emergency upper and lower limits, it specifically addresses the situation where, in each grid-based energy storage unit of the off-grid microgrid, at least one energy storage unit is charging even when its SOC exceeds the emergency upper limit, while no other energy storage unit is discharging even when its SOC is below the emergency lower limit. This indicates an energy imbalance where some energy storage units are overcharged but there is no over-discharge. By controlling the SOC to between the emergency upper and lower limits, overcharging and over-discharging of the energy storage are avoided, effectively extending the energy storage life.

[0095] The method includes:

[0096] If, in each grid-type energy storage unit of an off-grid microgrid, there is at least one energy storage unit whose SOC exceeds the emergency upper limit and is still charging, and no other energy storage unit whose SOC is below the emergency lower limit and is still discharging, then the energy storage unit that exceeds the emergency upper limit and is still charging is the energy storage unit that needs compensation, and the compensation is adjusted upwards one by one.

[0097] The second compensation power is allocated to the second energy storage units to be allocated, with each increase in power of the energy storage unit requiring compensation being the second compensation power. The second energy storage units to be allocated are all energy storage units with a State of Charge (SOC) below the economic limit. The second compensation power is allocated according to the ratio of the discharge depth of each energy storage unit to the sum of the discharge depths of all energy storage units to be allocated; the larger the ratio, the more is allocated. If, after the allocated compensation power is added, there is a second energy storage unit to be allocated that exceeds the maximum discharge power, then that energy storage unit is removed from the second energy storage units to be allocated, and the second compensation power is redistributed to the remaining second energy storage units to be allocated. If there are no second energy storage units to be allocated, the adjustment ends.

[0098] The emergency cap is greater than the economic cap.

[0099] Therefore, this method addresses the energy imbalance situation where some energy storage units are overcharged but not over-discharged. It fully considers SOC control, maintaining the SOC between the emergency upper and lower limits to prevent overcharging and over-discharging, effectively extending the energy storage lifespan. The increased power from overcharged energy storage units is evenly distributed only to units whose SOC does not exceed the economic upper and lower limits. This unifies energy storage SOC balance control, off-grid microgrid stable operation, and reliable power supply in remote areas within a single control framework. While maximizing renewable energy absorption and ensuring the safe and stable operation of the energy storage system, it strictly ensures that the SOC of each energy storage unit does not fall below the emergency lower limit, meeting the grid support requirements of multi-grid energy storage systems. Simultaneously, it guarantees that the SOC of each energy storage unit does not exceed the economic upper and lower limits, effectively avoiding the risks of overcharging damage and lifespan degradation, thus extending the lifespan of the energy storage system and reducing operation and maintenance costs. Its application scenarios are not limited to off-grid microgrids in high-altitude remote areas; it can also be extended to various off-grid scenarios without large-scale grid support, such as high-altitude pastoral areas, remote villages, and isolated island power supply, demonstrating broad applicability and outstanding practical value.

[0100] In this embodiment, each energy storage unit requiring compensation is adjusted downwards sequentially, following the order from oldest to youngest since the last control. This minimizes frequent adjustments to certain energy storage units, extending their lifespan and ensuring the safe and stable operation of the energy storage system. In other embodiments, the energy storage units requiring compensation are adjusted downwards in a different order, such as by pre-defined numbers or according to importance.

[0101] In addition, during power regulation, the adjustment amplitude of a single energy storage unit requiring compensation is strictly limited to a set step size until the predetermined power regulation task is completed. The small-step gradual adjustment mode can prevent the single power regulation amplitude (i.e., the second power requiring compensation in a single instance) from being too large, resulting in an insufficient number of available energy storage units for allocating power, and can also effectively suppress large fluctuations in power and voltage in off-grid microgrids.

[0102] In one specific embodiment, the definition is... #The SOC of energy storage is And its range is Set an allowable upper limit for the State of Charge (SOC) of energy storage. The emergency limit is 0.9. The economic ceiling is 0.8. The lower limit of the economic curve is 0.7. The emergency lower limit is 0.3. The lower limit is 0.2. It is 0.1.

[0103] In this embodiment, among the grid-type energy storage units of the off-grid microgrid, there exists at least one energy storage unit whose SOC exceeds the emergency upper limit and is still charging, while no other energy storage unit has an SOC below the emergency lower limit and is still discharging; that is, there exists a non-empty subset. , so that: , And for other energy storage units: , .

[0104] First, adjust the grid-type energy storage system, which was implemented a long time ago. Assuming... #Energy storage (of which) The primary energy storage unit to be adjusted (i.e., the first energy storage unit that needs compensation) is adjusted in steps, with each adjustment amount not exceeding the step size, until its power is adjusted to the lower limit of the power control dead zone of the energy storage unit.

[0105] Each upward adjustment amount is recorded as Based on this, the allocation method is to allocate power deviation according to the SOC of all other grid-type energy storage with a SOC lower than the economic SOC upper limit, assuming... B represents the set of all other grid-type energy storage units with a State of Charge (SOC) below the economic SOC upper limit that will not exceed the maximum discharge power of the energy storage, i.e., the set of the second energy storage units to be allocated; where, for #Energy storage (of which) The upward adjustment amount (i.e., the second power to be compensated) is This is equivalent to allocating the required compensation power corresponding to the upward adjustment amount of the energy storage unit to be controlled according to the proportion of the discharge depth of each grid-type energy storage unit to the sum of the discharge depths of all grid-type energy storage units in B (the discharge depth is the complement of the SOC). The larger the proportion, the more compensation power is allocated. If there is an energy storage unit whose allocated compensation power exceeds the maximum discharge power of the energy storage, then the energy storage unit is removed from B, and the compensation power is redistributed among the energy storage units in B. If so, the adjustment will end prematurely. After adjusting the power of the energy storage unit to its target value, continue to retrieve the energy storage unit index subset. The elements in, until completion. Set traversal. Taking an off-grid microgrid containing three grid-connected energy storage units as an example, the flowchart is as follows: Figure 3 .

[0106] Furthermore, to avoid frequent switching of charging and discharging states by the energy storage unit near zero power, the methods for determining whether the power regulation of the current energy storage unit requiring compensation has been completed include:

[0107] If the power of the energy storage unit requiring compensation has been adjusted to within the set power control dead zone, the determination bit indicates that the power adjustment of the current energy storage unit requiring compensation is complete; the actual power of the energy storage unit within the set power control dead zone is 0. In one specific embodiment, the power control dead zone of the energy storage is set to ±5% of the rated power; that is, if the rated power of each energy storage unit is 100kW, then when the commanded power is between -5kW and +5kW, it is considered that the energy storage unit is within the set power control dead zone, and the actual power of the energy storage unit is 0. In other embodiments, the conditions for determining whether the power adjustment of the current energy storage unit requiring compensation is complete can also be flexibly set, such as adjusting the power of the current energy storage unit requiring compensation to a specified value or meeting a certain number of adjustment times.

[0108] The off-grid microgrid grid-based energy storage balancing control method in this embodiment establishes a dynamic regulation mechanism, taking into account both grid constraints and economic objectives. It achieves precise balancing control of multiple SOCs under multiple grid-based energy storage, while ensuring the stable operation of the off-grid microgrid and the reliability of power supply in remote areas. This promotes the large-scale application and high-quality development of off-grid microgrids in high-altitude and remote areas.

[0109] Furthermore, this embodiment can not only be applied independently to the situation where some energy storage units are overcharged but there is no energy imbalance due to over-discharge, but it can also be combined with the first embodiment of the above method. When it is necessary to address the situation where some energy storage units are over-discharged but there is no energy imbalance due to overcharging, the above solution of the first embodiment of the above method can be adopted; when it is necessary to address the situation where some energy storage units are overcharged but there is no energy imbalance due to over-discharge, the above solution of this embodiment can be adopted.

[0110] Second Implementation Method of Grid-Based Energy Storage Balance Control System for Off-Grid Microgrids

[0111] This embodiment presents a technical solution for a grid-connected energy storage balancing control system for an off-grid microgrid, referring to... Figure 7 This includes a memory, a processor, and a computer program stored in the memory. The processor executes the computer program to implement the following steps of a grid-connected energy storage balancing control method for off-grid microgrids, specifically including:

[0112] If, in each grid-type energy storage unit of an off-grid microgrid, there is at least one energy storage unit whose SOC exceeds the emergency upper limit and is still charging, and no other energy storage unit whose SOC is below the emergency lower limit and is still discharging, then the energy storage unit that exceeds the emergency upper limit and is still charging is the energy storage unit that needs compensation, and the compensation is adjusted upwards one by one.

[0113] The second compensation power is allocated to the second energy storage units to be allocated, with each increase in power of the energy storage unit requiring compensation being the second compensation power. The second energy storage units to be allocated are all energy storage units with a State of Charge (SOC) below the economic limit. The second compensation power is allocated according to the ratio of the discharge depth of each energy storage unit to the sum of the discharge depths of all energy storage units to be allocated; the larger the ratio, the more is allocated. If, after the allocated compensation power is added, there is a second energy storage unit to be allocated that exceeds the maximum discharge power, then that energy storage unit is removed from the second energy storage units to be allocated, and the second compensation power is redistributed to the remaining second energy storage units to be allocated. If there are no second energy storage units to be allocated, the adjustment ends.

[0114] The emergency cap is greater than the economic cap.

[0115] Therefore, this system addresses the energy imbalance situation where some energy storage units are overcharged but not over-discharged. It fully considers SOC control, maintaining the SOC between the emergency upper and lower limits to prevent overcharging and over-discharging, effectively extending the energy storage lifespan. The increased power from overcharged energy storage units is evenly distributed only to units whose SOC does not exceed the economic upper and lower limits. This unifies energy storage SOC balance control, off-grid microgrid stable operation, and reliable power supply in remote areas within a single control framework. While maximizing renewable energy absorption and ensuring the safe and stable operation of the energy storage system, it strictly ensures that the SOC of each energy storage unit does not fall below the emergency lower limit, meeting the grid support requirements of multi-grid energy storage systems. Simultaneously, it ensures that the SOC of each energy storage unit does not exceed the economic upper and lower limits, effectively avoiding the risks of overcharging damage and lifespan degradation, thus extending the lifespan of the energy storage system and reducing operation and maintenance costs. Its application scenarios are not limited to off-grid microgrids in high-altitude remote areas; it can also be extended to various off-grid scenarios without large-scale grid support, such as high-altitude pastoral areas, remote villages, and isolated island power supply, demonstrating broad applicability and outstanding practical value.

[0116] In this embodiment, each energy storage unit requiring compensation is adjusted downwards sequentially, following the order from oldest to youngest since the last control. This minimizes frequent adjustments to certain energy storage units, extending their lifespan and ensuring the safe and stable operation of the energy storage system. In other embodiments, the energy storage units requiring compensation are adjusted downwards in a different order, such as by pre-defined numbers or according to importance.

[0117] In addition, during power regulation, the adjustment amplitude of a single energy storage unit requiring compensation is strictly limited to a set step size until the predetermined power regulation task is completed. The small-step gradual adjustment mode can prevent the single power regulation amplitude (i.e., the second power requiring compensation in a single instance) from being too large, resulting in an insufficient number of available energy storage units for allocating power, and can also effectively suppress large fluctuations in power and voltage in off-grid microgrids.

[0118] In one specific embodiment, the definition is... #The SOC of energy storage is And its range is Set an allowable upper limit for the State of Charge (SOC) of energy storage. The emergency limit is 0.9. The economic ceiling is 0.8. The lower limit of the economic curve is 0.7. The emergency lower limit is 0.3. The lower limit is 0.2. It is 0.1.

[0119] In this embodiment, among the grid-type energy storage units of the off-grid microgrid, there exists at least one energy storage unit whose SOC exceeds the emergency upper limit and is still charging, while no other energy storage unit has an SOC below the emergency lower limit and is still discharging; that is, there exists a non-empty subset. , so that: , And for other energy storage units: , .

[0120] First, adjust the grid-type energy storage system, which was implemented a long time ago. Assuming... #Energy storage (of which) The primary energy storage unit to be adjusted (i.e., the first energy storage unit that needs compensation) is adjusted in steps, with each adjustment amount not exceeding the step size, until its power is adjusted to the lower limit of the power control dead zone of the energy storage unit.

[0121] Each upward adjustment amount is recorded as Based on this, the allocation method is to allocate power deviation according to the SOC of all other grid-type energy storage with a SOC lower than the economic SOC upper limit, assuming... B represents the set of all other grid-type energy storage units with a State of Charge (SOC) below the economic SOC upper limit that will not exceed the maximum discharge power of the energy storage, i.e., the set of the second energy storage units to be allocated; where, for #Energy storage (of which) The upward adjustment amount (i.e., the second power to be compensated) is This is equivalent to allocating the required compensation power corresponding to the upward adjustment amount of the energy storage unit to be controlled according to the proportion of the discharge depth of each grid-type energy storage unit to the sum of the discharge depths of all grid-type energy storage units in B (the discharge depth is the complement of the SOC). The larger the proportion, the more compensation power is allocated. If there is an energy storage unit whose allocated compensation power exceeds the maximum discharge power of the energy storage, then the energy storage unit is removed from B, and the compensation power is redistributed among the energy storage units in B. If so, the adjustment will end prematurely. After adjusting the power of the energy storage unit to its target value, continue to retrieve the energy storage unit index subset. The elements in, until completion. Set traversal. Taking an off-grid microgrid containing three grid-connected energy storage units as an example.

[0122] Furthermore, to avoid frequent switching of charging and discharging states by the energy storage unit near zero power, the methods for determining whether the power regulation of the current energy storage unit requiring compensation has been completed include:

[0123] If the power of the energy storage unit requiring compensation has been adjusted to within the set power control dead zone, the determination bit indicates that the power adjustment of the current energy storage unit requiring compensation is complete; the actual power of the energy storage unit within the set power control dead zone is 0. In one specific embodiment, the power control dead zone of the energy storage is set to ±5% of the rated power; that is, if the rated power of each energy storage unit is 100kW, then when the commanded power is between -5kW and +5kW, it is considered that the energy storage unit is within the set power control dead zone, and the actual power of the energy storage unit is 0. In other embodiments, the conditions for determining whether the power adjustment of the current energy storage unit requiring compensation is complete can also be flexibly set, such as adjusting the power of the current energy storage unit requiring compensation to a specified value or meeting a certain number of adjustment times.

[0124] The off-grid microgrid grid-based energy storage equalization control system in this embodiment establishes a dynamic regulation mechanism, taking into account both grid constraints and economic objectives. This achieves precise equalization control of multiple SOCs under multiple grid-based energy storage systems, while ensuring the stable operation of the off-grid microgrid and the reliability of power supply in remote areas. This promotes the large-scale application and high-quality development of off-grid microgrids in high-altitude and remote areas.

[0125] Furthermore, this embodiment can not only be applied independently to the situation where some energy storage units are overcharged but there is no energy imbalance due to over-discharge, but it can also be combined with the first embodiment of the system described above. When it is necessary to address the situation where some energy storage units are over-discharged but there is no energy imbalance due to overcharging, the above-described solution of the first embodiment of the system is adopted; when it is necessary to address the situation where some energy storage units are overcharged but there is no energy imbalance due to over-discharge, the above-described solution of this embodiment is adopted.

[0126] Third Implementation Method of Grid-Based Energy Storage Balance Control Method for Off-Grid Microgrids

[0127] This embodiment presents a technical solution for a grid-based energy storage balancing control method in an off-grid microgrid. Based on setting emergency upper and lower limits, it specifically addresses the situation where, in each grid-based energy storage unit of the off-grid microgrid, at least one energy storage unit is discharging even when its State of Charge (SOC) is below the emergency lower limit, and at least one energy storage unit is charging even when its SOC is above the emergency upper limit. This results in improper circulating currents among the energy storage units, i.e., an energy imbalance due to improper circulating currents. The SOC is then used to sequentially control the power of each pair of energy storage units with the highest current discharge power and the highest current charging power to eliminate improper circulating currents.

[0128] The method includes: if, in an off-grid microgrid, at least one energy storage unit has a State of Charge (SOC) below the emergency lower limit and is still discharging, and at least one energy storage unit has a SOC above the emergency upper limit and is still charging, resulting in improper circulating current between the energy storage units, then the two energy storage units with the highest current discharge power and the highest current charging power are selected; under total power discharge conditions, the energy storage units with the highest discharge and charging power allocate the adjustment target according to the proportion of their own SOC to the sum of their own and the other's SOC, with a larger proportion allocating a larger proportion of the adjustment target; under total power charging conditions, the energy storage units with the highest discharge and charging power allocate the adjustment target according to the proportion of their own discharge depth to the sum of their own and the other's discharge depth, with a larger proportion allocating a larger proportion of the adjustment target; the adjustment target is determined based on the combined power of the two energy storage units to be adjusted; after adjustment, the two energy storage units with the highest current discharge power and the highest current current charging power are reselected, and adjustment continues until there is no improper circulating current.

[0129] Therefore, this method addresses energy imbalances caused by improper circulating currents. By adjusting only the two energy storage units with the highest current discharge and charging power in each adjustment cycle, and repeatedly selecting and balancing these two units, it ultimately eliminates all circulating currents within the entire microgrid framework. This unifies energy storage SOC balancing control, off-grid microgrid stable operation, and reliable power supply in remote areas within a single control framework. It improves renewable energy absorption, ensures the safe and stable operation of the energy storage system, and effectively avoids the risks of overcharging damage and lifespan degradation, thereby extending the system's lifespan and reducing maintenance costs. Its application scenarios are not limited to off-grid microgrids in high-altitude remote areas; it can also be extended to various off-grid scenarios without large-scale grid support, such as high-altitude pastoral areas, remote villages, and isolated island power supply, demonstrating broad applicability and outstanding practical value.

[0130] In one specific embodiment, among the grid-connected energy storage units in an off-grid microgrid, at least one energy storage unit is discharging even when its State of Charge (SOC) is below the emergency lower limit, and at least one energy storage unit is charging even when its SOC is above the emergency upper limit. This results in an improper circulating current among the energy storage units, i.e., the existence of a non-empty subset. ,and , so that: , ,and , And for , .

[0131] First, select the two energy storage units with the highest discharge power and the highest charging power for adjustment, assuming... #Energy Storage and #Energy storage is at its maximum discharge power and maximum charging power, i.e. , Then, based on the total power of both and the state of charge / discharge of the total power, the adjustment result is proportionally adjusted according to the SOC.

[0132] That is, under total power discharge conditions, #Energy storage power adjustment , #Energy storage power adjustment This is equivalent to allocating the adjustment target based on the proportion of the energy storage unit with the largest discharge power and the largest charging power to the sum of its own SOC and the other party's SOC. The larger the proportion, the larger the proportion of the adjustment target allocated. The adjustment target is determined based on the combined power of the two energy storage units to be adjusted.

[0133] Under total power charging conditions #Energy storage power adjustment , #Energy storage power adjustment This means that the energy storage units with the highest discharge power and the highest charging power allocate the adjustment target according to the proportion of their own discharge depth to the sum of their own and the other's discharge depths. The larger the proportion, the larger the proportion of the adjustment target allocated. The adjustment target is determined based on the combined power of the two energy storage units to be adjusted.

[0134] After multiple rounds of adjustment, the adjustment process ends when no improper circulation is found. Specifically, as follows... Figure 4 As shown.

[0135] Furthermore, this embodiment can not only be applied independently to situations where at least one energy storage unit in an off-grid microgrid is discharging below the emergency lower limit and charging above the emergency upper limit, resulting in improper circulating currents between energy storage units, but it can also be combined with at least one scheme in the first and second embodiments of the above-mentioned method. When it is necessary to address the energy imbalance situation where some energy storage units are over-discharged but there is no overcharging, the scheme of the first embodiment of the above-mentioned method is adopted; when it is necessary to address the energy imbalance situation where some energy storage units are overcharged but there is no over-discharge, the scheme of the second embodiment of the above-mentioned method is adopted; and when it is necessary to address the situation where at least one energy storage unit in an off-grid microgrid is discharging below the emergency lower limit and charging above the emergency upper limit, resulting in improper circulating currents between energy storage units, the above-mentioned scheme of this embodiment is adopted.

[0136] Third Implementation Method of Grid-Based Energy Storage Balance Control System for Off-Grid Microgrids

[0137] This embodiment presents a technical solution for a grid-connected energy storage balancing control system for an off-grid microgrid, referring to... Figure 7 This includes a memory, a processor, and a computer program stored in the memory. The processor executes the computer program to implement the following steps of a grid-connected energy storage balancing control method for off-grid microgrids, specifically including:

[0138] If, in an off-grid microgrid, at least one energy storage unit has a State of Charge (SOC) below the emergency lower limit while still discharging, and at least one energy storage unit has a SOC above the emergency upper limit while still charging, resulting in improper circulating current among the energy storage units, then the two energy storage units with the highest current discharge power and the highest current charging power are selected. Under total power discharge conditions, the energy storage units with the highest discharge and charging power allocate the adjustment target according to the proportion of their own SOC to the sum of their own and the other's SOCs; the larger the proportion, the larger the proportion of the allocated adjustment target. Under total power charging conditions, the energy storage units with the highest discharge and charging power allocate the adjustment target according to the proportion of their own discharge depth to the sum of their own and the other's discharge depths; the larger the proportion, the larger the proportion of the allocated adjustment target. The adjustment target is determined based on the combined power of the two energy storage units to be adjusted. After adjustment, the two energy storage units with the highest current discharge and charging power are reselected, and adjustment continues until improper circulating current is eliminated.

[0139] Therefore, this system addresses energy imbalances caused by improper circulating currents by balancing the power distribution between the two energy storage units with the highest current discharge and charging power in each adjustment cycle. This process is repeated cyclically, ultimately eliminating all circulating currents within the energy storage units of the entire microgrid. This unifies energy storage SOC balancing control, off-grid microgrid stability, and reliable power supply in remote areas within a single control framework. It improves renewable energy absorption, ensures the safe and stable operation of the energy storage system, and effectively avoids the risks of overcharging damage and lifespan degradation, thereby extending the system's lifespan and reducing maintenance costs. Its application scenarios are not limited to off-grid microgrids in high-altitude remote areas; it can also be extended to various off-grid scenarios without large-scale grid support, such as high-altitude pastoral areas, remote villages, and isolated island power supply, demonstrating broad applicability and outstanding practical value.

[0140] In one specific embodiment, among the grid-connected energy storage units in an off-grid microgrid, at least one energy storage unit is discharging even when its State of Charge (SOC) is below the emergency lower limit, and at least one energy storage unit is charging even when its SOC is above the emergency upper limit. This results in an improper circulating current among the energy storage units, i.e., the existence of a non-empty subset. ,and , so that: , ,and , And for , .

[0141] First, select the two energy storage units with the highest discharge power and the highest charging power for adjustment, assuming... #Energy Storage and #Energy storage is at its maximum discharge power and maximum charging power, i.e. , Then, based on the total power of both and the state of charge / discharge of the total power, the adjustment result is proportionally adjusted according to the SOC.

[0142] That is, under total power discharge conditions, #Energy storage power adjustment , #Energy storage power adjustment This is equivalent to allocating the adjustment target based on the proportion of the energy storage unit with the largest discharge power and the largest charging power to the sum of its own SOC and the other party's SOC. The larger the proportion, the larger the proportion of the adjustment target allocated. The adjustment target is determined based on the combined power of the two energy storage units to be adjusted.

[0143] Under total power charging conditions #Energy storage power adjustment , #Energy storage power adjustment This means that the energy storage units with the highest discharge power and the highest charging power allocate the adjustment target according to the proportion of their own discharge depth to the sum of their own and the other's discharge depths. The larger the proportion, the larger the proportion of the adjustment target allocated. The adjustment target is determined based on the combined power of the two energy storage units to be adjusted.

[0144] After multiple rounds of adjustment, the adjustment ends when there is no longer any improper circulation.

[0145] Furthermore, this embodiment can not only be applied independently to situations where at least one energy storage unit in an off-grid microgrid is discharging below the emergency lower limit and charging above the emergency upper limit, resulting in improper circulating currents between energy storage units, but it can also be combined with at least one scheme in the first and second embodiments of the system described above. When it is necessary to address the energy imbalance situation where some energy storage units are over-discharged but there is no overcharging, the scheme of the first embodiment of the system is adopted; when it is necessary to address the energy imbalance situation where some energy storage units are overcharged but there is no over-discharge, the scheme of the second embodiment of the system is adopted; and when it is necessary to address the situation where at least one energy storage unit in an off-grid microgrid is discharging below the emergency lower limit and charging above the emergency upper limit, resulting in improper circulating currents between energy storage units, the scheme of this embodiment is adopted.

[0146] Fourth Implementation Method of Grid-Based Energy Storage Balance Control Method for Off-Grid Microgrids

[0147] This embodiment presents a technical solution for a grid-based energy storage balancing control method in an off-grid microgrid. Considering economic efficiency, for situations where all grid-based energy storage units in the off-grid microgrid are in a discharging state, the minimum SOC of an energy storage unit is lower than the economic lower limit, the difference between the maximum and minimum SOC of an energy storage unit is greater than the economic lower limit of a first set proportion, and the discharge power of the energy storage unit with the maximum SOC is less than the discharge power of the energy storage unit with the minimum SOC, the energy storage units with the maximum and minimum SOC are adjusted to ensure the economic performance of the discharging state.

[0148] The method includes:

[0149] If all grid-type energy storage units in an off-grid microgrid are in a discharging state, the minimum SOC of an energy storage unit is below the economic minimum limit, the difference between the maximum and minimum SOC of an energy storage unit is greater than the economic minimum limit of a first set proportion, and the discharge power of the energy storage unit with the maximum SOC is less than the discharge power of the energy storage unit with the minimum SOC, then the power regulation targets for the maximum and minimum SOC energy storage units are allocated according to the proportion of their own SOC to the sum of their own and the other's SOC. The larger the proportion, the larger the proportion of the allocated regulation target. The regulation target is determined based on the combined power of the two energy storage units to be regulated.

[0150] This method addresses energy imbalances where the overall energy storage system is discharging, some energy storage units have a State of Charge (SOC) below the economic minimum, and there are significant SOC differences between energy storage units. By adjusting the distribution of power between the two energy storage units with the highest and lowest SOCs in each adjustment cycle, and repeatedly selecting and distributing these two units, the method ensures that the energy storage units maintain a relatively good operating condition (operating within the economic minimum range reduces degradation and loss) within permissible charging and discharging power limits. This unifies energy storage SOC balance control, stable operation of off-grid microgrids, and reliable power supply in remote areas within a single control framework. It improves renewable energy absorption, ensures the safe and stable operation of the energy storage system, and effectively avoids the risks of overcharging damage and lifespan degradation, thereby extending the lifespan of the energy storage system and reducing operation and maintenance costs. Its application scenarios are not limited to off-grid microgrids in high-altitude remote areas; it can also be extended to various off-grid scenarios without large-scale grid support, such as high-altitude pastoral areas, remote villages, and isolated island power supply, demonstrating broad applicability and outstanding practical value.

[0151] Specifically, the economic lower bound is greater than the emergency lower bound. In one specific embodiment, it is defined as follows: #The SOC of energy storage is And its range is Set an allowable upper limit for the State of Charge (SOC) of energy storage. The emergency limit is 0.9. The economic ceiling is 0.8. The lower limit of the economic curve is 0.7. The emergency lower limit is 0.3. The lower limit is 0.2. It is 0.1.

[0152] If all energy storage devices are in a discharged state, there exists a minimum energy storage SOC that is below the economic lower limit, and the difference between the maximum and minimum energy storage SOC is greater than [missing value]. Economic floor ( The value is the first set ratio (which can be adjusted), and the discharge power of the grid-type energy storage with the maximum SOC is less than the discharge power of the energy storage with the minimum SOC.

[0153] At this point, the power regulation targets for maximum and minimum SOC energy storage are allocated proportionally according to SOC; that is, #Energy storage power adjustment , #Energy storage power adjustment ;in, , This is equivalent to allocating adjustment targets based on the proportion of the maximum and minimum SOC energy storage units to the sum of their own and each other's SOCs; the larger the proportion, the larger the proportion of the adjustment target allocated. The adjustment target is determined by combining the power of the two energy storage units to be adjusted; specifically, as follows... Figure 5 As shown.

[0154] Furthermore, this embodiment can be applied independently not only to situations where all grid-type energy storage units in an off-grid microgrid are in a discharging state, the minimum SOC of an energy storage unit is below the economic minimum limit, the difference between the maximum and minimum SOC of an energy storage unit is greater than the economic minimum limit of a first set proportion, and the discharge power of the energy storage unit with the maximum SOC is less than the discharge power of the energy storage unit with the minimum SOC, but also in combination with at least one of the solutions in the first, second, and third embodiments of the above method. When it is necessary to address the energy imbalance situation where some energy storage units are over-discharged but there is no overcharging, the solution of the first embodiment of the above method is adopted; when it is necessary to address the energy imbalance situation where some energy storage units are overcharged but there is no over-discharge, the solution of the second embodiment of the above method is adopted. The second implementation scheme is adopted when, in the case where, among the grid-type energy storage units of an off-grid microgrid, at least one energy storage unit is still discharging even though its SOC is below the emergency lower limit, and at least one energy storage unit is still charging even though its SOC is above the emergency upper limit, resulting in improper circulating current between energy storage units, the third implementation scheme is adopted when, in the case where, all grid-type energy storage units of an off-grid microgrid are in a discharging state, the smallest energy storage unit has a SOC below the economic lower limit, the difference between the largest and smallest energy storage units is greater than the economic lower limit of a first set proportion, and the discharge power of the energy storage unit with the largest SOC is less than the discharge power of the energy storage unit with the smallest SOC, the above-described scheme of this implementation scheme is adopted.

[0155] Fourth Implementation Method of Grid-Based Energy Storage Balance Control System for Off-Grid Microgrids

[0156] This embodiment presents a technical solution for a grid-connected energy storage balancing control system for an off-grid microgrid, referring to... Figure 7 This includes a memory, a processor, and a computer program stored in the memory. The processor executes the computer program to implement the following steps of a grid-connected energy storage balancing control method for off-grid microgrids, specifically including:

[0157] If all grid-type energy storage units in an off-grid microgrid are in a discharging state, the minimum SOC of an energy storage unit is below the economic minimum limit, the difference between the maximum and minimum SOC of an energy storage unit is greater than the economic minimum limit of a first set proportion, and the discharge power of the energy storage unit with the maximum SOC is less than the discharge power of the energy storage unit with the minimum SOC, then the power regulation targets for the maximum and minimum SOC energy storage units are allocated according to the proportion of their own SOC to the sum of their own and the other's SOC. The larger the proportion, the larger the proportion of the allocated regulation target. The regulation target is determined based on the combined power of the two energy storage units to be regulated.

[0158] This system addresses energy imbalances where the entire energy storage system is discharging, some energy storage units have a State of Charge (SOC) below the economic minimum, and there are significant SOC differences between energy storage units. By adjusting the system in each cycle, it balances the distribution of power between the two energy storage units with the highest and lowest SOCs, repeatedly selecting and balancing these units. Ultimately, this ensures that the energy storage units maintain a relatively good operating condition (operating within the economic minimum range reduces degradation and loss) within the limits of charging and discharging power. This unifies energy storage SOC balance control, off-grid microgrid stability, and reliable power supply in remote areas within a single control framework. It improves renewable energy absorption, ensures the safe and stable operation of the energy storage system, and effectively avoids the risks of overcharging damage and lifespan degradation, thereby extending the system's lifespan and reducing maintenance costs. Its application scenarios are not limited to off-grid microgrids in high-altitude remote areas; it can also be extended to various off-grid scenarios without large-scale grid support, such as high-altitude pastoral areas, remote villages, and isolated island power supply, demonstrating broad applicability and outstanding practical value.

[0159] Specifically, the emergency cap is greater than the economic cap; in one specific implementation, it is defined as follows: #The SOC of energy storage is And its range is Set an allowable upper limit for the State of Charge (SOC) of energy storage. The emergency limit is 0.9. The economic ceiling is 0.8. The lower limit of the economic curve is 0.7. The emergency lower limit is 0.3. The lower limit is 0.2. It is 0.1.

[0160] If all energy storage devices are in a discharged state, there exists a minimum energy storage SOC that is below the economic lower limit, and the difference between the maximum and minimum energy storage SOC is greater than [missing value]. Economic floor ( The value is the first set ratio (which can be adjusted), and the discharge power of the grid-type energy storage with the maximum SOC is less than the discharge power of the energy storage with the minimum SOC.

[0161] At this point, the power regulation targets for maximum and minimum SOC energy storage are allocated proportionally according to SOC; that is, #Energy storage power adjustment , #Energy storage power adjustment ;in, , This is equivalent to allocating adjustment targets based on the proportion of the maximum and minimum SOC energy storage units to the sum of their own and each other's SOCs; the larger the proportion, the larger the proportion of the adjustment target allocated. The adjustment target is determined based on the combined power of the two energy storage units to be adjusted.

[0162] Furthermore, this embodiment can be applied independently not only to situations where all grid-type energy storage units in an off-grid microgrid are in a discharging state, the minimum SOC of an energy storage unit is below the economic minimum limit, the difference between the maximum and minimum SOC of an energy storage unit is greater than the economic minimum limit of a first set proportion, and the discharge power of the energy storage unit with the maximum SOC is less than the discharge power of the energy storage unit with the minimum SOC, but also in combination with at least one of the solutions in the first, second, and third embodiments of the above system. When it is necessary to address the energy imbalance situation where some energy storage units are over-discharged but there is no overcharging, the solution of the first embodiment of the above system is adopted; when it is necessary to address the energy imbalance situation where some energy storage units are overcharged but there is no over-discharge, the solution of the second embodiment of the above system is adopted. The second implementation scheme; when there is a situation where, among the various grid-type energy storage units in an off-grid microgrid, at least one energy storage unit is discharging even though its SOC is below the emergency lower limit, and at least one energy storage unit is charging even though its SOC exceeds the emergency upper limit, resulting in improper circulating current between energy storage units, the scheme of the third implementation scheme of the above system is adopted; when all grid-type energy storage units in an off-grid microgrid are in a discharging state, there is a situation where the minimum energy storage unit's SOC is below the economic lower limit, the difference between the maximum and minimum energy storage units' SOC is greater than the economic lower limit of a first set proportion, and the discharge power of the energy storage unit with the maximum SOC is less than the discharge power of the energy storage unit with the minimum SOC, the above scheme of this implementation scheme is adopted.

[0163] Fifth Implementation Method of Grid-Based Energy Storage Balance Control Method for Off-Grid Microgrids

[0164] This embodiment presents a technical solution for a grid-based energy storage balancing control method in an off-grid microgrid. Considering economic efficiency, for situations where all grid-based energy storage units in the off-grid microgrid are in a charging state, the maximum SOC of an energy storage unit is higher than the economic upper limit, the difference between the maximum and minimum SOC of an energy storage unit is greater than the economic upper limit of a second set ratio, and the charging power of the energy storage unit with the maximum SOC is greater than the charging power of the energy storage unit with the minimum SOC, the energy storage units with the maximum and minimum SOC are adjusted to ensure the economic performance in the discharge state.

[0165] The method includes:

[0166] If all grid-type energy storage units in an off-grid microgrid are in a charging state, the largest energy storage unit's SOC is higher than the economic upper limit, the difference between the largest and smallest energy storage units' SOC is greater than the second set proportion of the economic upper limit, and the charging power of the energy storage unit with the largest SOC is greater than the charging power of the energy storage unit with the smallest SOC, then the power regulation targets for the largest and smallest SOC energy storage units are allocated according to the proportion of their own discharge depth to the sum of their own and the other's discharge depths. The larger the proportion, the larger the proportion of the allocated regulation target. The regulation target is determined based on the combined power of the two energy storage units to be regulated.

[0167] This method addresses energy imbalances where the overall energy storage system is charging, some storage units have a State of Charge (SOC) exceeding the economic limit, and there are significant SOC differences between storage units. By adjusting the SOC of only the two storage units with the highest and lowest current SOCs in each adjustment cycle, and repeatedly selecting and balancing these two units, the method ensures that the energy storage units maintain a relatively good operating condition (operating within the economic upper and lower limits reduces degradation and loss) within the limits of charging and discharging power. This unifies energy storage SOC balancing control, stable operation of off-grid microgrids, and reliable power supply in remote areas within a single control framework. It improves renewable energy absorption, ensures the safe and stable operation of the energy storage system, and effectively avoids the risks of overcharging damage and lifespan degradation, thereby extending the lifespan of the energy storage system and reducing operation and maintenance costs. Its application scenarios are not limited to off-grid microgrids in high-altitude remote areas; it can also be extended to various off-grid scenarios without large-scale grid support, such as high-altitude pastoral areas, remote villages, and isolated island power supply, demonstrating broad applicability and outstanding practical value.

[0168] Specifically, the economic ceiling is less than the emergency ceiling; in one specific embodiment, it is defined as follows: #The SOC of energy storage is And its range is Set an allowable upper limit for the State of Charge (SOC) of energy storage. The emergency limit is 0.9. The economic ceiling is 0.8. The lower limit of the economic curve is 0.7. The emergency lower limit is 0.3. The lower limit is 0.2. It is 0.1.

[0169] If all energy storage devices are in a charging state, there exists a maximum energy storage SOC that exceeds the economic limit, and the difference between the maximum and minimum energy storage SOC is greater than [missing value]. Economic ceiling ( The value is the second set ratio (adjustable), and the charging power of the grid-type energy storage at the maximum SOC is greater than the charging power at the minimum SOC. In this case, the power adjustment targets for the maximum and minimum SOC energy storage are proportionally allocated according to the depth of discharge; that is, #Energy storage power adjustment , #Energy storage power adjustment ;in, , This means that the power regulation targets for the largest and smallest SOC energy storage units are allocated according to the proportion of their own discharge depth to the sum of their own and the other's discharge depths; the larger the proportion, the larger the allocated regulation target. The regulation target is determined based on the combined power of the two energy storage units to be regulated. Specifically, as follows... Figure 6 As shown.

[0170] Furthermore, this embodiment can be applied independently not only to situations where all grid-type energy storage units in an off-grid microgrid are charging, the largest energy storage unit's SOC is higher than the economic upper limit, the difference between the largest and smallest SOC of the energy storage units is greater than the second set economic upper limit, and the charging power of the energy storage unit with the largest SOC is greater than the charging power of the energy storage unit with the smallest SOC, but also to at least one of the solutions in the first, second, third, and fourth embodiments of the above method. When it is necessary to address the energy imbalance situation where some energy storage units are over-discharged but there is no overcharging, the solution of the first embodiment of the above method is used; when it is necessary to address the energy imbalance situation where some energy storage units are overcharged but there is no over-discharge, the solution of the second embodiment of the above method is used; and when it is necessary to address the energy imbalance situation where at least one energy storage unit in the off-grid microgrid has an SOC lower than the emergency lower limit and is still discharging, and at least one energy storage unit... When the SOC exceeds the emergency limit but charging continues, causing improper circulating currents between energy storage units, the solution of the third embodiment of the above method is adopted. When it is necessary for all grid-type energy storage units in the off-grid microgrid to be in a discharging state, and there is a minimum energy storage unit with a SOC below the economic lower limit, the difference between the maximum and minimum SOC of the energy storage units is greater than the first set economic lower limit, and the discharge power of the energy storage unit with the maximum SOC is less than the discharge power of the energy storage unit with the minimum SOC, the solution of the fourth embodiment of the above method is adopted. When it is necessary for all grid-type energy storage units in the off-grid microgrid to be in a charging state, and there is a maximum energy storage unit with a SOC above the economic upper limit, the difference between the maximum and minimum SOC of the energy storage units is greater than the second set economic upper limit, and the charging power of the energy storage unit with the maximum SOC is greater than the charging power of the energy storage unit with the minimum SOC, the solution of this embodiment is adopted.

[0171] Fifth Implementation Method of Grid-Based Energy Storage Balance Control System for Off-Grid Microgrids

[0172] This embodiment presents a technical solution for a grid-connected energy storage balancing control system for an off-grid microgrid, referring to... Figure 7 This includes a memory, a processor, and a computer program stored in the memory. The processor executes the computer program to implement the following steps of a grid-connected energy storage balancing control method for off-grid microgrids, specifically including:

[0173] If all grid-type energy storage units in an off-grid microgrid are in a charging state, the largest energy storage unit's SOC is higher than the economic upper limit, the difference between the largest and smallest energy storage units' SOC is greater than the second set proportion of the economic upper limit, and the charging power of the energy storage unit with the largest SOC is greater than the charging power of the energy storage unit with the smallest SOC, then the power regulation targets for the largest and smallest SOC energy storage units are allocated according to the proportion of their own discharge depth to the sum of their own and the other's discharge depths. The larger the proportion, the larger the proportion of the allocated regulation target. The regulation target is determined based on the combined power of the two energy storage units to be regulated.

[0174] This system addresses energy imbalances where the overall energy storage system is charging, some storage units have a State of Charge (SOC) exceeding the economic limit, and there are significant SOC differences between storage units. By adjusting the system in each cycle, it balances the distribution of power between the two storage units with the highest and lowest SOCs, repeatedly selecting and balancing these units. This ensures that the energy storage units maintain optimal operating conditions (operating within the economic limits reduces degradation and loss) within permissible charging and discharging power limits. This unifies SOC balance control, stable operation of off-grid microgrids, and reliable power supply in remote areas within a single control framework. It improves renewable energy integration, ensures the safe and stable operation of the energy storage system, and effectively avoids the risks of overcharging damage and lifespan degradation, extending the system's lifespan and reducing maintenance costs. Its application scenarios are not limited to off-grid microgrids in high-altitude remote areas; it can be extended to high-altitude pastoral areas, remote villages, isolated island power supply, and other off-grid scenarios without large-scale grid support, demonstrating broad applicability and outstanding practical value.

[0175] Specifically, the economic ceiling is less than the emergency ceiling; in one specific embodiment, it is defined as follows: #The SOC of energy storage is And its range is Set an allowable upper limit for the State of Charge (SOC) of energy storage. The emergency limit is 0.9. The economic ceiling is 0.8. The lower limit of the economic curve is 0.7. The emergency lower limit is 0.3. The lower limit is 0.2. It is 0.1.

[0176] If all energy storage devices are in a charging state, there exists a maximum energy storage SOC that exceeds the economic limit, and the difference between the maximum and minimum energy storage SOC is greater than [missing value]. Economic ceiling ( The value is the second set ratio (adjustable), and the charging power of the grid-type energy storage at the maximum SOC is greater than the charging power at the minimum SOC. In this case, the power adjustment targets for the maximum and minimum SOC energy storage are proportionally allocated according to the depth of discharge; that is, #Energy storage power adjustment , #Energy storage power adjustment ;in, , The power regulation targets for the maximum and minimum SOC energy storage units are allocated according to the proportion of their own discharge depth to the sum of their own and the other's discharge depths. The larger the proportion, the larger the proportion of the allocated regulation target. The regulation target is determined based on the combined power of the two energy storage units to be regulated.

[0177] Furthermore, this embodiment can be applied independently not only to situations where all grid-type energy storage units in an off-grid microgrid are charging, the largest energy storage unit's SOC is higher than the economic limit, the difference between the largest and smallest SOC of the energy storage units is greater than the second set economic limit, and the charging power of the energy storage unit with the largest SOC is greater than the charging power of the energy storage unit with the smallest SOC, but also to at least one of the solutions in the first, second, third, and fourth embodiments of the above system. When it is necessary to address the energy imbalance situation where some energy storage units are over-discharged but there is no overcharging, the solution of the first embodiment of the above system is adopted; when it is necessary to address the energy imbalance situation where some energy storage units are overcharged but there is no over-discharge, the solution of the second embodiment of the above system is adopted; and when it is necessary to address the energy imbalance situation where at least one energy storage unit in the off-grid microgrid has an SOC lower than the emergency lower limit and is still discharging, and at least one energy storage unit... When the SOC exceeds the emergency limit but charging continues, causing improper circulating currents between energy storage units, the solution of the third embodiment of the above system is adopted. When it is necessary for all grid-type energy storage units in the off-grid microgrid to be in a discharging state, and there is a minimum energy storage unit with a SOC below the economic lower limit, the difference between the maximum and minimum SOC of the energy storage units is greater than the first set economic lower limit, and the discharge power of the energy storage unit with the maximum SOC is less than the discharge power of the energy storage unit with the minimum SOC, the solution of the fourth embodiment of the above system is adopted. When it is necessary for all grid-type energy storage units in the off-grid microgrid to be in a charging state, and there is a maximum energy storage unit with a SOC above the economic upper limit, the difference between the maximum and minimum SOC of the energy storage units is greater than the second set economic upper limit, and the charging power of the energy storage unit with the maximum SOC is greater than the charging power of the energy storage unit with the minimum SOC, the solution of this embodiment is adopted.

[0178] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of the present invention and do not constitute a limitation thereof.

Claims

1. A method for constructing a network-type energy storage balancing control of an off-grid microgrid, characterized in that, include: If, in each grid-type energy storage unit of an off-grid microgrid, there is at least one energy storage unit whose SOC is below the emergency lower limit and is still discharging, and no other energy storage unit whose SOC is above the emergency upper limit and is still charging, then the energy storage unit that is discharging below the emergency lower limit is the one that needs compensation, and the energy storage units are adjusted downward one by one. The first compensation power is allocated to the first energy storage units to be allocated, with the power reduction of each energy storage unit required for compensation each time being the first compensation power. The first energy storage units to be allocated are all energy storage units with a State of Charge (SOC) higher than the economic minimum. The first compensation power is allocated according to the ratio of the SOC of each energy storage unit to the sum of the SOCs of all energy storage units to be allocated, with a larger ratio resulting in more units being allocated. If, after the allocated compensation power is added, there is an energy storage unit to be allocated that exceeds the maximum charging power, then that energy storage unit is removed from the first energy storage units to be allocated, and the first compensation power is redistributed to the remaining energy storage units to be allocated. If there is no energy storage unit to be allocated, the adjustment ends. The emergency floor is less than the economic floor.

2. The network-constructing type energy storage equalization control method of an off-grid type microgrid according to claim 1, characterized in that, Also includes: If, in each grid-type energy storage unit of an off-grid microgrid, there is at least one energy storage unit whose SOC exceeds the emergency upper limit and is still charging, and no other energy storage unit whose SOC is below the emergency lower limit and is still discharging, then the energy storage unit that exceeds the emergency upper limit and is still charging is the energy storage unit that needs compensation, and the compensation is adjusted upwards one by one. The second compensation power is allocated to the second energy storage units to be allocated, with each increase in power of the energy storage unit requiring compensation being the second compensation power. The second energy storage units to be allocated are all energy storage units with a State of Charge (SOC) below the economic limit. The second compensation power is allocated according to the ratio of the discharge depth of each energy storage unit to the sum of the discharge depths of all energy storage units to be allocated; the larger the ratio, the more is allocated. If, after the allocated compensation power is added, there is a second energy storage unit to be allocated that exceeds the maximum discharge power, then that energy storage unit is removed from the second energy storage units to be allocated, and the second compensation power is redistributed to the remaining second energy storage units to be allocated. If there are no second energy storage units to be allocated, the adjustment ends. The emergency cap is greater than the economic cap.

3. The grid-based energy storage balance control method for off-grid microgrids according to claim 1 or 2, characterized in that, Also includes: If, in an off-grid microgrid, at least one energy storage unit has a State of Charge (SOC) below the emergency lower limit and is still discharging, and at least one energy storage unit has a SOC above the emergency upper limit and is still charging, resulting in improper circulating current among the energy storage units, then the two energy storage units with the largest current discharge power and the largest current charging power are selected. Under total power discharge conditions, the energy storage units with the largest discharge and charging power allocate the regulation target according to the proportion of their own SOC to the sum of their own and the other's SOC; the larger the proportion, the larger the proportion of the allocated regulation target. Under total power charging conditions, the energy storage units with the largest discharge and charging power allocate the regulation target according to the proportion of their own discharge depth to the sum of their own and the other's discharge depth; the larger the proportion, the larger the proportion of the allocated regulation target. The adjustment target is determined based on the combined power of the two energy storage units to be adjusted. After the adjustment is completed, the two energy storage units with the largest current discharge power and the largest current charging power are selected again, and the adjustment continues until there is no improper circulating current.

4. The grid-based energy storage balance control method for off-grid microgrids according to claim 1 or 2, characterized in that, Also includes: If all grid-type energy storage units in an off-grid microgrid are in a discharging state, the minimum SOC of an energy storage unit is below the economic minimum limit, the difference between the maximum and minimum SOC of an energy storage unit is greater than the economic minimum limit of a first set proportion, and the discharge power of the energy storage unit with the maximum SOC is less than the discharge power of the energy storage unit with the minimum SOC, then the power regulation targets for the maximum and minimum SOC energy storage units are allocated according to the proportion of their own SOC to the sum of their own and the other's SOC. The larger the proportion, the larger the proportion of the allocated regulation target. The regulation target is determined based on the combined power of the two energy storage units to be regulated.

5. The grid-based energy storage equalization control method for off-grid microgrids according to claim 1 or 2, characterized in that, Also includes: If all grid-type energy storage units in an off-grid microgrid are in a charging state, the largest energy storage unit's SOC is higher than the economic limit, the difference between the largest and smallest energy storage units' SOC is greater than the second set proportion of the economic limit, and the charging power of the energy storage unit with the largest SOC is greater than the charging power of the energy storage unit with the smallest SOC, then the power regulation targets for the largest and smallest SOC energy storage units are allocated according to the proportion of their own discharge depth to the sum of their own and the other's discharge depths, with the larger the proportion, the larger the allocated regulation target percentage. The adjustment target is determined based on the combined power of the two energy storage units to be adjusted.

6. The grid-based energy storage balance control method for off-grid microgrids according to claim 1 or 2, characterized in that, When each energy storage unit requiring compensation is adjusted upwards, it is adjusted one by one in order from the earliest to the latest time since the last control.

7. The grid-based energy storage balance control method for off-grid microgrids according to claim 2, characterized in that, When each energy storage unit requiring compensation is adjusted downwards, it is adjusted one by one in order from the earliest to the earliest time since the last control.

8. The grid-based energy storage balance control method for off-grid microgrids according to claim 1 or 2, characterized in that, The methods for determining whether the power regulation of the current energy storage unit that needs compensation has been completed include: If the power of the energy storage unit that needs compensation has been adjusted to within the set power control dead zone, the determination bit completes the power adjustment of the energy storage unit that needs compensation; the actual power of the energy storage unit within the set power control dead zone is 0.

9. The grid-based energy storage balance control method for off-grid microgrids according to claim 1 or 2, characterized in that, Each adjustment for a compensated energy storage unit shall not exceed a set step size until the power adjustment of the current compensated energy storage unit is completed.

10. A grid-based energy storage balancing control system for an off-grid microgrid, comprising a memory, a processor, and a computer program stored in the memory, characterized in that, The processor executes the computer program to implement the steps of the grid-based energy storage balancing control method for off-grid microgrids according to any one of claims 1-9.

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