Energy distribution method and device for hybrid microgrid considering energy storage operation constraint

Abstract

The application provides a kind of hybrid microgrid energy distribution method and device considering energy storage operation constraint, it is related to microgrid energy management technical field, the application includes: obtaining microgrid multi-source operation data;Based on the change of new energy output, the state of external grid power taking, the state of energy storage backup and the state of grid stability, generate off-grid risk index, and determine economic operation, resilience enhancement or anti-islanding operation mode accordingly;Based on the state of energy storage unit electric quantity deviation, charge-discharge ratio and temperature state, generate healthy available charge-discharge power as call boundary;According to the reliability requirement of load power supply, the priority of load guarantee is divided, and power distribution instruction is generated combining operation mode and healthy available charge-discharge power;In response to risk removal into recovery stage, charge in order of main energy storage priority, auxiliary energy storage delay, the application realizes active defense of off-grid risk, energy storage health constraint scheduling and post-fault resilience priority recovery.

Description

Technical Field

[0001] This invention relates to the field of microgrid energy management technology, specifically to a hybrid microgrid energy distribution method and apparatus that takes into account energy storage operation constraints. Background Technology

[0002] Currently, in the energy management of hybrid microgrids that include new energy sources, energy storage, and diesel power generation equipment, a unified optimization dispatch strategy is usually adopted with the goal of minimizing electricity purchase costs or balancing supply and demand. Most of these existing solutions treat energy storage as an ideal device with constant rated power and capacity, only setting upper and lower limits of state of charge as constraints, and assuming that the external power grid is stable and available.

[0003] However, in scenarios such as islands and peripheral industrial parks, microgrids often face challenges such as fluctuations in the upper-level grid, short-term off-grid risks, and drastic changes in wind and solar power output. Existing technologies have significant shortcomings in dealing with these conditions: firstly, they lack the ability to quantify and predict off-grid risks in advance, often passively switching operating modes only after a fault occurs, leading to untimely restoration of power to critical loads; secondly, they do not fully consider the dynamic impact of energy storage temperature, rate of operation, and energy deviation on actual available capacity, easily overdrawing energy storage lifespan under high-temperature or high-rate operating conditions; furthermore, directly restoring economic dispatch after a fault is resolved may result in the energy storage safety boundary not being rebuilt before encountering risks again, reducing the system's secondary resilience. Therefore, a microgrid energy allocation method that can balance energy storage health, critical load protection, and rapid post-fault recovery under off-grid risk conditions is needed.

[0004] The information disclosed in the background section is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a hybrid microgrid energy distribution method and apparatus that takes into account energy storage operation constraints, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A hybrid microgrid energy allocation method considering energy storage operation constraints, wherein the hybrid microgrid includes energy storage units, and the energy storage units include primary energy storage and auxiliary energy storage, the method comprising: Acquire multi-source operation data of the microgrid; Based on the changes in renewable energy output, external grid power intake status, energy storage reserve status, and grid stability status from multi-source operation data, the degree of renewable energy output fluctuation, external grid dependence, energy storage reserve insufficiency, and grid instability are generated respectively. Off-grid risk indicators are generated based on the degree of renewable energy output fluctuation, external grid dependence, energy storage reserve insufficiency, and grid instability. According to the risk level of the off-grid risk indicators, the current operation mode of the microgrid is determined as economic operation mode, resilience enhancement operation mode, or anti-islanding operation mode. Among them, economic operation mode, resilience enhancement operation mode, and anti-islanding operation mode correspond to different energy storage reservation requirements and load shedding permissions. Based on the degree to which the energy storage unit's state of charge deviates from the safe operating range, the degree to which its charge / discharge rate and temperature exceed the reference temperature, a healthy and usable charge / discharge power is generated, and this healthy and usable charge / discharge power is used as the boundary for the energy storage unit to participate in energy allocation. Based on the power supply reliability requirements of the loads in the microgrid, the loads are divided into critical load layers, general load layers and interruptible load layers to form load protection priorities. Based on the current operating mode, load protection priorities and healthy available charging and discharging power, power allocation instructions are generated under power balance constraints and issued to control the energy distribution of the microgrid. In response to the off-grid risk indicators meeting the risk relief conditions, the system enters the recovery and recharging phase. The recharging is carried out in the order of priority restoration of the safe power boundary for the main energy storage and delayed restoration of the auxiliary energy storage. After the recovery exit conditions are met, the system returns to normal operation mode.

[0007] Furthermore, based on the changes in renewable energy output, external grid power intake status, energy storage reserve status, and grid stability status in multi-source operation data, the following parameters are generated: renewable energy output fluctuation level, external grid dependence level, energy storage reserve insufficiency level, and grid instability level, including: The total output of renewable energy sources over the most recent scheduling cycles is obtained, and the degree of fluctuation of renewable energy output is generated based on the magnitude of change of the total output of renewable energy sources over the multiple scheduling cycles. The greater the magnitude of change, the higher the degree of fluctuation of renewable energy output. The power drawn by the microgrid from the external grid and the total load power of the microgrid are obtained, and the external grid dependence is generated based on the proportion of the power drawn from the external grid to the total load power. The higher the proportion, the higher the external grid dependence. The remaining available power of the main energy storage and auxiliary energy storage after deducting the safety lower limit is obtained, and the power required by the critical load within the set guarantee period is obtained. The energy storage reserve insufficiency is generated based on the comparison between the remaining available power and the required power. The more insufficient the remaining available power is relative to the required power, the higher the energy storage reserve insufficiency. The voltage fluctuation and frequency deviation at the microgrid grid connection point are obtained, and the grid instability is generated based on the voltage fluctuation and frequency deviation. The greater the voltage fluctuation and the greater the frequency deviation, the higher the grid instability. Off-grid risk indicators are generated based on the degree of fluctuation in new energy output, the degree of dependence on external power grid, the degree of insufficiency of energy storage reserves, and the degree of grid instability. The off-grid risk indicators are then compared with the first risk threshold and the second risk threshold. When the off-grid risk indicator is lower than the first risk threshold, the current operating mode will be determined as the economic operating mode. When the off-grid risk indicator is not lower than the first risk threshold and is lower than the second risk threshold, the current operation mode will be determined as the resilience-enhanced operation mode. When the off-network risk indicator is not lower than the second risk threshold, the current operating mode will be determined as the anti-islanding operating mode.

[0008] Furthermore, based on the degree to which the energy storage unit's state of charge deviates from its safe operating range, its charge / discharge rate status, and its temperature status exceed the reference temperature, healthy and usable charge / discharge power is generated, including: The state of charge, charge / discharge rate, and temperature of the main energy storage and the auxiliary energy storage are obtained respectively. A health coefficient for the main energy storage is generated based on the degree to which the energy state of the main energy storage deviates from the safe operating range, the charge / discharge rate represented by the charge / discharge rate state of the main energy storage, and the degree to which the temperature state of the main energy storage exceeds the reference temperature. An auxiliary energy storage health coefficient is generated based on the degree to which the state of charge of the auxiliary energy storage deviates from the safe operating range, the charge-discharge rate characterized by the charge-discharge rate of the auxiliary energy storage, and the degree to which the temperature of the auxiliary energy storage exceeds the reference temperature. The rated charge and discharge capacity of the main energy storage is reduced based on the main energy storage health coefficient to generate the main energy storage healthy usable charge and discharge power. The rated charge and discharge capacity of the auxiliary energy storage is reduced based on the auxiliary energy storage health coefficient to generate the healthy and usable charge and discharge power of the auxiliary energy storage. The healthy available charging and discharging power of the main energy storage and the healthy available charging and discharging power of the auxiliary energy storage are used together as the healthy available charging and discharging power.

[0009] Furthermore, based on the main energy storage health coefficient, the rated charge and discharge capacity of the main energy storage is reduced to generate the healthy and usable charge and discharge power of the main energy storage, including: In the direction of main energy storage discharge, the rated discharge power of the main energy storage is reduced based on the health coefficient of the main energy storage to obtain the reduced discharge power of the main energy storage. The allowable discharge power of the main energy storage is determined based on the amount of energy that can be released between the current energy level of the main energy storage and the safe lower limit energy level of the main energy storage, the discharge efficiency of the main energy storage, and the scheduling cycle. The smaller of the main energy storage reduced discharge power and the main energy storage allowable discharge power is determined as the main energy storage healthy available discharge power. In the direction of main energy storage charging, the rated charging power of the main energy storage is reduced based on the health coefficient of the main energy storage to obtain the reduced charging power of the main energy storage. The allowable charging power of the main energy storage is determined based on the amount of electricity that can be absorbed between the current energy capacity and the safe upper limit of the main energy storage, the charging efficiency of the main energy storage, and the scheduling cycle. The smaller of the main energy storage reduced charging power and the main energy storage allowed charging power is determined as the main energy storage healthy available charging power. The healthy available discharge power of the main energy storage and the healthy available charging power of the main energy storage together constitute the healthy available charging and discharging power of the main energy storage. The rated charge / discharge capacity of the auxiliary energy storage is reduced based on the auxiliary energy storage health coefficient to generate the healthy and usable charge / discharge power of the auxiliary energy storage, including: In the direction of auxiliary energy storage discharge, the rated discharge power of auxiliary energy storage is reduced based on the auxiliary energy storage health coefficient to obtain the reduced discharge power of auxiliary energy storage. The allowable discharge power of the auxiliary energy storage is determined based on the amount of energy that can be released between the current power of the auxiliary energy storage and the safe lower limit power of the auxiliary energy storage, the discharge efficiency of the auxiliary energy storage, and the scheduling cycle. The smaller of the auxiliary energy storage reduced discharge power and the auxiliary energy storage allowable discharge power is determined as the healthy available discharge power of the auxiliary energy storage. In the direction of auxiliary energy storage charging, the rated charging power of auxiliary energy storage is reduced based on the health coefficient of auxiliary energy storage to obtain the reduced charging power of auxiliary energy storage; The allowable charging power of the auxiliary energy storage is determined based on the amount of energy that can be absorbed between the current power of the auxiliary energy storage and the safe upper limit power of the auxiliary energy storage, the charging efficiency of the auxiliary energy storage, and the scheduling cycle. The smaller of the auxiliary energy storage reduced charging power and the auxiliary energy storage allowed charging power is determined as the healthy available charging power of the auxiliary energy storage. The healthy available discharge power of auxiliary energy storage and the healthy available charging power of auxiliary energy storage together constitute the healthy available charging and discharging power of auxiliary energy storage.

[0010] Furthermore, based on the current operating mode, load protection priority, and healthy available charging and discharging power, a power allocation instruction is generated under power balance constraints, including: The critical load layer is set as the priority protection object, the general load layer is set as the object that can be reduced or delayed in power supply, and the interruptible load layer is set as the object that will be gradually withdrawn as the off-grid risk index increases. When the current operating mode is anti-islanding operating mode, interruptible load layers are disconnected first, while critical load layers are kept powered. Under power balance constraints, the healthy and available charging and discharging power of the main energy storage and the healthy and available charging and discharging power of the auxiliary energy storage are used as the energy storage call boundaries. Combined with the current operating mode and the power supply sequence of the critical load layer, general load layer and interruptible load layer, the grid connection interface power command, diesel generator power command, main energy storage power command, auxiliary energy storage power command, general load shelving power command, interruptible load shelving power command and energy curtailment power command are generated. When the current operating mode is the economic operating mode, the main energy storage is allowed to participate in economic charging and discharging adjustments; When the current operating mode is the resilience enhancement operating mode, the main energy storage is controlled to maintain reserved power and the discharge depth of the main energy storage is limited; When the current operating mode is the anti-islanding operating mode, the main energy storage is controlled to discharge to the critical load layer first, and the economic charging of the main energy storage is stopped. At the same time, the interruptible load layer is cut off according to the off-grid risk index. The grid connection interface power command, diesel generator power command, main energy storage power command, auxiliary energy storage power command, general load shedding power command, interruptible load shedding power command, and curtailment power command will be issued and executed as power allocation commands.

[0011] Furthermore, the hybrid microgrid also includes diesel generators. When generating power distribution commands, diesel generator power commands are generated based on power balance constraints to control the output power of the diesel generators.

[0012] Furthermore, in response to the off-grid risk indicators meeting the risk relief conditions, the system enters the recovery and recharging phase. Recharging is performed in the order of prioritizing the restoration of the main energy storage to the safe power boundary, with auxiliary energy storage being restored later. This includes: When the churn event ends, or when the churn risk indicator falls from above the second risk threshold to below the recovery threshold, the recovery and recharge phase begins. During the recovery and recharging phase, obtain the current energy level of the main energy storage, the safe target energy level of the main energy storage, and the healthy available charging power of the main energy storage. Based on the current energy level of the main energy storage, the safe target energy level of the main energy storage, and the healthy available charging power of the main energy storage, the main energy storage recharge power is generated, and the main energy storage is controlled to charge according to the main energy storage recharge power. Before the main energy storage capacity reaches the main energy storage safety target capacity, the auxiliary energy storage recharge power will be kept at zero. Once the main energy storage reaches the main energy storage safety target, the current energy storage, the auxiliary energy storage target, and the auxiliary energy storage healthy and available charging power are obtained. Based on the current power level of the auxiliary energy storage, the target power level of the auxiliary energy storage, and the healthy available charging power of the auxiliary energy storage, the auxiliary energy storage recharge power is generated, and the auxiliary energy storage is controlled to charge according to the auxiliary energy storage recharge power.

[0013] Furthermore, based on the current energy level of the main energy storage, the safe target energy level of the main energy storage, and the healthy available charging power of the main energy storage, the main energy storage recharge power is generated, including: The difference between the main energy storage safety target capacity and the current capacity of the main energy storage is determined as the difference in the amount of main energy storage to be recharged. Based on the main energy storage charging efficiency and scheduling cycle, the difference in the amount of main energy storage waiting to be recharged is converted into the power required to complete the recharge within the scheduling cycle, which is used as the target recharge power of the main energy storage. The smaller of the main energy storage healthy available charging power and the main energy storage target recharge power is determined as the main energy storage recharge power. Based on the current auxiliary energy storage capacity, the target auxiliary energy storage capacity, and the healthy available charging power of the auxiliary energy storage, the auxiliary energy storage recharge power is generated, including: The difference between the target capacity of the auxiliary energy storage and the current capacity of the auxiliary energy storage is determined as the difference in the amount of auxiliary energy storage to be recharged. Based on the auxiliary energy storage charging efficiency and scheduling cycle, the difference in the amount of auxiliary energy storage waiting to be recharged is converted into the power required to complete the recharge within the scheduling cycle, which is used as the target recharge power of the auxiliary energy storage. The smaller of the auxiliary energy storage healthy available charging power and the auxiliary energy storage target recharge power is determined as the auxiliary energy storage recharge power.

[0014] Furthermore, the target capacity for main energy storage safety is determined based on the backup capacity required for the next risk event, and the target capacity for main energy storage safety is lower than the full charge capacity; The target capacity of auxiliary energy storage is lower than the safe target capacity of main energy storage. During the recovery and recharge phase, priority will continue to be given to ensuring the critical load layer; When the current power of the main energy storage reaches the safety target power of the main energy storage, the current power of the auxiliary energy storage reaches the target power of the auxiliary energy storage, and the off-grid risk indicator continues to be lower than the recovery threshold for a set number of cycles, the recovery and recharging phase will be exited. After exiting the recovery and recharging phase, the current operating mode is redefined based on the off-grid risk indicators; After the power allocation command is issued and executed, or after exiting the recharge recovery phase, it also includes: After a scheduling cycle ends, obtain the actual power supplied and the actual load power of the microgrid. Calculate the power balance deviation between the actual supplied power and the actual load power; When the power balance deviation exceeds the set balance threshold, the power compensation amount for the next scheduling cycle is generated based on the power balance deviation. The power compensation amount is added to the power allocation instruction of the next scheduling cycle; Update off-grid risk indicators, current operating mode, and the healthy and available charging and discharging power of the main energy storage and auxiliary energy storage to enable the microgrid to enter the next dispatch cycle. The present invention also provides a hybrid microgrid energy distribution device considering energy storage operation constraints, the device being used to execute the above-described hybrid microgrid energy distribution method considering energy storage operation constraints, comprising: The data acquisition module is used to acquire multi-source operational data of the microgrid; The output analysis module is used to generate the degree of new energy output fluctuation, external grid dependence, energy storage reserve insufficiency, and grid instability based on the changes in new energy output, external grid power intake status, energy storage reserve status, and grid stability status in multi-source operation data. Based on the degree of new energy output fluctuation, external grid dependence, energy storage reserve insufficiency, and grid instability, it generates off-grid risk indicators. According to the risk level of the off-grid risk indicators, it determines the current operation mode of the microgrid as economic operation mode, resilience enhancement operation mode, or anti-islanding operation mode. The economic operation mode, resilience enhancement operation mode, and anti-islanding operation mode correspond to different energy storage reservation requirements and load shedding permissions, respectively. The boundary generation module is used to generate healthy and usable charge and discharge power based on the degree to which the energy storage unit's state of charge deviates from the safe operating range, the charge and discharge rate status, and the degree to which the temperature status exceeds the reference temperature. The healthy and usable charge and discharge power is used as the call boundary for the energy storage unit to participate in energy allocation. The energy distribution module is used to divide the load into critical load layer, general load layer and interruptible load layer according to the power supply reliability requirements of the load in the microgrid, form load protection priority, and generate power distribution instructions under power balance constraints based on the current operating mode, load protection priority and healthy available charging and discharging power, and issue power distribution instructions to control the energy distribution of the microgrid. The operation control module is used to respond to the off-grid risk indicators meeting the risk relief conditions and enter the recovery and recharging phase. It performs recharging in the order of prioritizing the restoration of the safe power boundary of the main energy storage and delaying the restoration of the auxiliary energy storage, and resumes normal operation mode after meeting the recovery exit conditions.

[0015] Compared with the prior art, the beneficial effects of the present invention are: This invention constructs a multi-dimensional off-grid risk index that incorporates factors such as renewable energy output fluctuations, external grid dependence, energy storage reserves, and grid stability. This transforms the system from passive fault response to proactive risk defense, enabling it to switch to resilient or anti-islanding operation modes before the actual off-grid risk occurs. This proactively adjusts energy storage reservation strategies and load protection priorities, significantly reducing the probability of critical load outages during sudden off-grid events. Simultaneously, by considering the energy storage unit's state of charge deviation, charge / discharge rate, and temperature, a healthy and usable charge / discharge power is dynamically generated as a hard constraint for energy allocation. This changes the traditional extensive approach of scheduling based on rated capacity, effectively preventing excessive overdraft of energy storage under high temperature, high charge / discharge rate, or unsafe energy ranges, and delaying energy storage lifespan degradation. Furthermore, after a risk event is resolved, a strategy of prioritizing the restoration of safe energy boundaries for primary energy storage and delaying the restoration of auxiliary energy storage ensures that the system has resilience reserves to cope with the next potential risk from the initial recovery stage, rather than blindly pursuing instantaneous economic benefits. Combined with a load stratification guarantee mechanism, this achieves synergistic optimization of microgrid power supply reliability, energy storage health, and system resilience under complex operating conditions. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall method flow of the present invention.

[0017] Figure 2 This is a schematic diagram of the overall device structure of the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0019] It should be noted that, unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0020] Example: Please see Figure 1 The present invention provides a technical solution: A hybrid microgrid energy allocation method considering energy storage operation constraints is described in this embodiment for ease of understanding, using a hybrid microgrid of an island hospital and a cold chain warehousing joint park as an application scenario. This microgrid includes a photovoltaic array, wind turbine generators, diesel generators, a main energy storage battery pack, an auxiliary supercapacitor energy storage unit, and an external grid connection interface. It should be understood that although this embodiment uses an island hospital as an example, this method is also applicable to microgrid scenarios with high requirements for power supply continuity and energy storage security, such as remote mining areas, data centers, and cold chain logistics parks. The method in this embodiment is executed through an energy management system, and the specific steps include: Step 1: Obtain multi-source operation data of the microgrid.

[0021] In this embodiment, multi-source operational data serves as the unified data foundation for subsequent off-grid risk identification and energy allocation, and its completeness and accuracy directly determine the reliability of risk indicators. This step is specifically executed in the following manner.

[0022] First, the data collection targets are determined, and various operational parameters are collected in real time. In this embodiment, the data collection targets cover all key power source-load-storage devices within the microgrid, specifically including: the real-time power output of the photovoltaic array. Real-time output of wind turbine generator sets Real-time output of diesel generators Grid-connected switching power State of charge of the main energy storage battery pack ,temperature Terminal voltage and current State of charge of auxiliary energy storage unit ,temperature Terminal voltage and current Critical load power General load power Interruptible load power ; and voltage fluctuation rate at the grid connection point and frequency deviation These data are collected in real time through smart meters, battery management systems (BMS), power quality monitoring devices, and load controllers. The reason for collecting data from four sources simultaneously—the power source side, the energy storage side, the load side, and the grid connection point—is that off-grid risk is essentially the result of the interaction between the power source, load, energy storage, and the external power grid. No single-dimensional data can fully characterize the vulnerability of the system; only multi-source data can support the quantification of the four risk dimensions.

[0023] Secondly, the collected data is resampled using a unified time-scale. Since the original sampling frequencies of different devices vary—for example, the sampling frequency of a power quality monitoring device is on the order of milliseconds, while the reporting cycle of a battery management system is on the order of seconds—directly using the raw data for scheduling decisions would lead to misalignment of physical quantities at the same time due to inconsistent time granularity, potentially causing misjudgments. Therefore, this embodiment resamples all collected data according to a unified scheduling cycle. Resampling is performed. For raw data with a sampling frequency higher than the scheduling period, the arithmetic mean within the time window is used as the representative value for that scheduling period. The calculation formula is as follows: in, This represents the uniform data value within the k-th scheduling period. This represents the j-th original sampled value within the scheduling period. This represents the total number of original sampling points within the scheduling cycle. The formula uses an arithmetic average instead of instantaneous or peak values ​​because microgrid scheduling focuses on the energy level within a scheduling cycle, not instantaneous spikes. The arithmetic average filters out high-frequency sampling noise, reflects the true energy level within the cycle, and has low computational complexity and is easily implemented online. Scheduling cycle The value of needs to be determined by balancing response speed and computational burden: Too small a value will lead to frequent optimization calculations, increased communication and computational burden, and susceptibility to transient disturbances; An excessively large value will lead to a delayed risk response, making it impossible to promptly detect rapidly changing churn risks. This embodiment will... The timeframe is set to 5 minutes, which aligns with the typical scheduling granularity of microgrid energy management systems, balancing real-time performance and stability on a minute-level risk evolution timescale. For data with a sampling frequency lower than the scheduling cycle, the latest valid value within that cycle is used as the representative value.

[0024] Next, the physical boundary validity of the resampled data is verified. To prevent outliers caused by sensor jitter or communication failures from interfering with the control logic, each sampling point is verified. The verification rule is configured as follows: when the sampled value is within a preset physical allowable range... If the value is within the specified range, retain the original value; otherwise, use the valid value from the previous period or the preset safe default value. Physically allowed range The settings are based on the inherent physical constraints and industry standards of each physical quantity: for example, the state of charge. Physically, it can only exist between 0 and 1, hence the main energy storage The physical allowable range is set as The frequency deviation at the grid connection point is set within the allowable range according to the power grid operation standards. The lower bound for power-related physical quantities is set to 0 or the upper limit of allowed reverse power, while the upper bound is set to the rated capacity of the corresponding equipment. This physical constraint-based verification eliminates "dirty" data that clearly violates physical laws at the source, preventing it from entering subsequent risk calculations and causing erroneous scheduling instructions.

[0025] This step, through three stages—collection, resampling, and verification—outputs multi-source operational data with a unified timescale and validated effectiveness. The technical benefit of this step is that it provides a time-aligned and physically reliable data foundation for the subsequent generation of off-grid risk indicators, ensuring that risk quantification results are not affected by sampling inconsistencies or outliers. This is a prerequisite for the reliable operation of the entire method.

[0026] Step 2: Based on the changes in renewable energy output, external grid power intake status, energy storage reserve status, and grid stability status in the multi-source operation data, generate renewable energy output fluctuation degree, external grid dependence degree, energy storage reserve insufficiency degree, and grid instability degree, respectively. Based on the renewable energy output fluctuation degree, external grid dependence degree, energy storage reserve insufficiency degree, and grid instability degree, generate off-grid risk indicators. According to the risk level of the off-grid risk indicators, determine the current operation mode of the microgrid as economic operation mode, resilience enhancement operation mode, or anti-islanding operation mode. The economic operation mode, resilience enhancement operation mode, and anti-islanding operation mode correspond to different energy storage reservation requirements and load shedding permissions, respectively.

[0027] The core of this step lies in quantifying the abstract off-grid risk into calculable real-time indicators, thereby shifting from passive fault response to proactive trend prediction. The four dimensions chosen—new energy output changes, external grid power intake status, energy storage reserve status, and grid stability status—correspond to four typical triggers of microgrid off-grid risk: internal power gaps caused by drastic fluctuations in new energy sources, cascading power outages due to excessive reliance on the external grid, insufficient energy storage reserves leading to a lack of supply guarantee capabilities, and the risk of grid disconnection due to fragility of the upstream grid. These four dimensions are independent yet collectively contribute to off-grid risk, and none can be omitted. The following sections explain the generation method, formula design rationale, parameter calibration basis, and technical effects of each sub-indicator.

[0028] First, generate the fluctuation level of new energy power output. Obtain the most recent... Total output of new energy sources within a scheduling cycle That is, the sum of photovoltaic power output and wind power output, and calculate its standard deviation within the sliding window. The calculation formula is as follows: in, For the most recent The average output of new energy sources within each scheduling cycle The sliding window length is given. This formula uses the standard deviation rather than a simple difference in output or rate of change because the standard deviation characterizes the overall dispersion of output relative to the mean within the window. It can simultaneously reflect high-frequency fluctuations and large increases in force, and is equally sensitive to deviations in both positive and negative directions, preventing the underestimation of risk due to the cancellation of positive and negative fluctuations. Sliding window length The value of needs to be determined by balancing sensitivity and stability: If the value is too small, the indicator will be overly sensitive to single instantaneous disturbances, which may easily trigger mode switching erroneously. If the value is too large, the indicator will have excessive inertia and will be unable to capture the intensifying fluctuation trend in a timely manner. This embodiment will... Set to 12, during the scheduling cycle The 5-minute interval corresponds to a 1-hour observation window. This duration is sufficient to cover the typical upswing process of wind and solar power output caused by cloud cover and gusts, while also filtering out instantaneous spikes on the order of seconds. Therefore, it represents a good trade-off between sensitivity and stability. The technical effect of this indicator is to transform the randomness and unpredictability of new energy sources into comparable values. The larger the standard deviation, the higher the probability of a power shortage in the near future, and the greater the instantaneous balance pressure faced by the system.

[0029] Secondly, the degree of dependence on external power grids is generated. The calculation formula is as follows: The numerator represents the power drawn from the external power grid, and the denominator represents the total load power of the microgrid, i.e., the critical load power. General load power With interruptible load power The sum. The molecule uses... The non-negative part of the grid-connected switching power is taken because dependence on external power sources only exists when the microgrid purchases power from an external grid; when... A negative value indicates that when the microgrid is supplying power to the external grid, the system does not rely on external power sources; in this case, the dependence should be zero. Taking the non-negative part avoids misjudging the power supply status as dependence. The denominator is normalized using the total load power, making this indicator a dimensionless proportion between 0 and 1. This facilitates weighted aggregation with other indicators of the same order of magnitude and makes its meaning intuitive: a higher proportion indicates a larger share of the current load relies on external grid supply, a weaker internal self-balancing capacity, and a more severe impact on the system should an external grid fail or experience a planned power outage. This indicator requires no additional calibration parameters and is directly calculated from real-time collected grid-connected switching power and load power. Its technical advantage lies in depicting the microgrid's dependence on external power sources in real time, providing a basis for predicting the risk of grid disconnection.

[0030] Next, the degree of energy storage reserve insufficiency is generated. First, the remaining usable electricity after deducting the respective safety lower limits of the main and auxiliary energy storage is calculated. Then, in conjunction with critical loads, set the protection duration. Power required By comparison, the energy storage reserve ratio is obtained. The calculation formula is as follows: in, , These are the rated capacities of the main energy storage and auxiliary energy storage, respectively. , These represent the current states of charge of the main energy storage and auxiliary energy storage, respectively. , These are the safety lower limits for both. For critical load power, This is the required backup time for critical loads. The numerator is reduced by the safety lower limit because the amount of electricity below the safety lower limit is reserved to prevent over-discharge and protect battery life; it cannot be used for actual power supply. Only the amount of electricity above the safety lower limit is truly available for reserve, ensuring that the calculated reserve level accurately reflects the available power supply capacity. The denominator is calculated by multiplying the critical load power by the backup time, i.e., the critical load's backup time. The required power supply, and the reserve capacity constructed in this way. This directly answers the core question of how long current energy storage reserves can support critical load operations. This indicates that current energy storage reserves are insufficient to support critical loads for the expected duration, and the degree of reserve insufficiency increases with... Decrease and increase. Duration guaranteed. The setting is based on the supply requirements of critical loads, such as hospital operating rooms and vaccine cold storage facilities where interruptions are not allowed. Set to 4 hours to cover the repair cycle of a typical external power grid fault; safety lower limit The setting is based on the discharge cutoff conditions and life decay curves provided by battery manufacturers, aiming to strike a balance between supply capacity and battery life protection. The technical advantage of this indicator is that it directly links the state of energy storage to load guarantee requirements, rather than viewing it in isolation. Numerical values ​​ensure that risk assessment always revolves around the essential goal of ensuring supply capacity.

[0031] Finally, the grid instability level is generated based on the voltage fluctuation rate at the grid connection point. and frequency deviation Comprehensive Assessment. Voltage fluctuation reflects the degree of rapid change in voltage at the grid connection point and can be obtained from the statistical characteristics of the voltage sequence collected by power quality monitoring devices within a time window; frequency deviation reflects the real-time imbalance of the system's active power. These two quantities are chosen as representations of grid stability because when a fault or heavy load occurs in the upstream grid, it often manifests first as voltage flicker and frequency drift before potentially developing into complete grid disconnection. Therefore, monitoring these two quantities can detect early signs of grid deterioration before actual grid disconnection occurs. These two quantities do not have independent conversion formulas but are directly included as additive terms in the following comprehensive grid disconnection risk index, with their respective weighting coefficients determining their contribution to the overall risk.

[0032] Based on the above four sub-indicators, a comprehensive churn risk index is generated. The calculation formula is as follows: in, , , , , These are the weighting coefficients. To prevent small positive numbers with a denominator of zero, the formula uses a weighted summation. This is because the four sub-indicators characterize off-grid risk from different dimensions, and the weighted summation integrates multi-dimensional information into a single, comparable comprehensive indicator. Furthermore, the physical meaning of each weight is clear, facilitating adjustments based on different scenarios. The formula includes two normalization designs: the degree of fluctuation in new energy output is normalized using... Divide by average output The relative volatility is obtained in the form of [variable name], making microgrids of different installed capacities comparable and avoiding the consistently high risk of large installed systems due to large absolute volatility; the degree of energy storage reserve insufficiency is [determined by] [variable name]. The reciprocal form, because of the reserve degree Smaller values ​​represent higher risk. Taking the reciprocal transforms the relationship of lower reserves leading to higher risk into a monotonically increasing positive contribution. Furthermore, the risk rises sharply as reserves approach zero, reflecting the abrupt change in risk when reserves are depleted. (Small positive numbers) For example, a value of 1e-6 is used to prevent division by zero errors when the average output or reserve is zero. Its value is much smaller than the normal order of magnitude of each physical quantity and does not affect the calculation results. Weighting coefficient , , , , The calibration is not arbitrarily set, but is determined based on regression analysis of historical off-grid event data, or, when sufficient historical data is lacking, using the analytic hierarchy process (AHP) based on expert experience. Specifically, when historical off-grid event records exist, the values ​​of each sub-indicator before the historical event are used as samples, and regression analysis is used to fit the weight combination that significantly increases the risk indicator before the off-grid event. When historical data is insufficient, operational experts compare the relative importance of each dimension pairwise, construct a judgment matrix, and solve for the weights. Regardless of the method used, the weights must satisfy the normalization constraint, that is, the sum of all weights must be 1, to ensure... The values ​​fall within an interpretable range. This calibration method, based on data or expert experience, ensures that risk indicators accurately reflect weaknesses in specific scenarios: for example, in an island scenario, if historical data shows that grid voltage flicker is the main cause of grid disconnection, then... The value is relatively high; if insufficient energy storage reserves have led to serious accidents, then... The values ​​are relatively high. After weighting, it can be verified by backtesting historical operating conditions and observing... The system analyzes whether a anticipated surge occurs before a known off-grid event, and iteratively adjusts accordingly. The technical effectiveness of this comprehensive indicator lies in fusing risk signals from four dimensions into a unified, real-time quantitative value, providing a basis for classifying operational modes.

[0033] After generating the churn risk indicators, based on the churn risk indicators Compared with the preset first risk threshold Second risk threshold The comparison result determines the current operating mode: when Less than When, it is determined as the economic operating model; when Not less than and less than When, it is determined to be a resilience-enhanced operation mode; when Not less than At that time, it is determined to be in anti-islanding operation mode. Two thresholds. and The calibration is based on the risk tolerance classification requirements of microgrids: The risk limit is set as the limit at which the system can still safely make economic adjustments. The risk limit set as the mandatory defense state can be determined by statistical analysis of historical normal operating conditions. The distribution is determined, for example, by Taken as historical normal working conditions The higher quantiles will Taken before the historical off-grid incident. The typical lower bound is used to achieve a balance between false alarm rate and false negative rate. Three operating modes correspond to different energy storage reservation requirements and load shedding permissions: the economic operating mode corresponds to the lowest energy storage reservation requirement, allowing energy storage to participate in economic adjustments such as peak-valley arbitrage, with the lowest load shedding permission; the resilient operating mode corresponds to a higher energy storage reservation requirement, requiring energy storage to maintain more reserves and limiting discharge depth, with a moderate load shedding permission; and the anti-islanding operating mode corresponds to the highest energy storage reservation requirement, requiring energy storage to prioritize critical loads, with the highest load shedding permission. The technical effect of this hierarchical design is to allow the scheduling strategy to smoothly transition with the risk level, avoiding drastic policy changes at risk thresholds. It is important to emphasize that the off-grid risk indicator here is "trend prediction" rather than "post-fault detection," meaning that before the actual off-grid event occurs, the system has already sensed the environmental deterioration and adjusted the energy storage reservation and load shedding strategies in advance, thus gaining a defense window. This is the key difference between this step and conventional islanding detection.

[0034] Step 3: Based on the degree to which the energy storage unit's state of charge deviates from the safe operating range, the degree to which its charge / discharge rate and temperature exceed the reference temperature, generate healthy and usable charge / discharge power, and use this healthy and usable charge / discharge power as the boundary for the energy storage unit to participate in energy allocation.

[0035] Existing technologies typically treat energy storage as an ideal device with a constant rated power, ignoring the impact of operating conditions on actual capacity and lifespan. This leads to the rigid utilization of rated power even under conditions of high temperature, high rate of operation, or low energy level, resulting in over-extension of the equipment. This step maps the physical health state of energy storage to a power reduction factor, achieving dynamic adaptation of the scheduling boundary to the actual state of the equipment. Specifically, healthy and usable charge and discharge power is generated for both primary and auxiliary energy storage. The following section uses primary energy storage as an example to illustrate the generation, reduction logic, and minimum constraint of the health factor, and provides the calibration basis for each parameter.

[0036] Taking main energy storage as an example, a health coefficient for main energy storage is generated based on the degree to which the state of charge deviates from the safe operating range, the degree of charge / discharge rate status, and the degree to which the temperature status exceeds the reference temperature. The calculation formula is as follows: ) in, The optimal operating SOC center value for primary energy storage Main energy storage rated current, For reference temperature, To determine the maximum permissible temperature, the formula uses a subtraction of three penalty terms from 1. This is because the health coefficient is essentially the energy storage capacity retention rate relative to the ideal state, which is 1 under ideal conditions. The three penalty terms correspond to three types of capacity decay mechanisms. The first term... It characterizes the degree to which the electrical state deviates from the safe operating range. The greater the deviation from the optimal operating center value, the stronger the electrochemical polarization effect inside the battery, and the lower the usable capacity. Therefore, the absolute value of the deviation is used as the penalty. (Second term) Characterizing the charge / discharge rate state, the relative magnitude of the rate is obtained by normalizing the absolute value of the current relative to the rated current. The higher the rate, the faster the ohmic heat and side reaction rate, and the usable capacity needs to be reduced accordingly; the third item The max function characterizes the degree to which the temperature exceeds the reference temperature. It ensures that only over-temperature conditions are penalized, not for low-temperature operation. The over-temperature amount is... After normalization, the penalty term is set to 0 at the reference temperature and 1 at the maximum allowable temperature. Excessive temperature accelerates SEI film growth and electrolyte decomposition, and is the most severe factor inducing performance degradation. Optimal operating SOC center value. The operating range is set based on the battery's electrochemical characteristics, where side reactions are minimized and polarization is weakest; for example, a range of 0.6. Reference temperature. The setting is 25℃, which is the standard ambient temperature for the battery's rated capacity; the maximum permissible temperature. The temperature is set at 55°C, determined by the thermal stability limit of the battery material system. These are the penalty weighting coefficients, with typical value ranges of [0.1, 0.3], [0.2, 0.4], and [0.3, 0.5]. The values ​​of the three weights are based on the severity of each factor's impact on capability decay: temperature has the most severe impact, therefore... The value is the largest, and the multiplier has the second largest influence. Centered The impact of deviation is relatively mild. Minimum. Specific values ​​can be obtained by fitting aging test curves provided by battery manufacturers, i.e., using different... The contribution of each factor is obtained by fitting the capacity retention data under various conditions (capacity, operating rate, and temperature). The fitting results can also be updated in real time through online parameter identification. The technical effect of this health coefficient is to dynamically characterize the actual usability of energy storage under current operating conditions, providing a basis for subsequent power reduction.

[0037] The rated charge / discharge capacity of the main energy storage is reduced based on the main energy storage health coefficient to generate the healthy and usable charge / discharge power. This employs a dual constraint logic, taking the smaller of the reduced power and the allowable power from the energy safety boundary. The reason for using this dual constraint is that the actual callable power of the energy storage is limited by two types of factors: one is the power capacity determined by the health state, i.e., the upper limit of power the battery can safely output under high-rate, high-temperature, or SOC deviation conditions; the other is the energy boundary determined by the remaining energy, i.e., the power corresponding to the energy that can be released or absorbed within the scheduling cycle between the current energy level and the safe upper and lower limits. If only health reduction is used, high power output may still be allowed when the energy level is close to the safe lower limit, leading to over-discharge; if only the energy boundary is used, the rated capacity may still be used when the health state deteriorates, leading to equipment overdraft. Therefore, the smaller of the two values ​​is taken, so that the final healthy and usable charge / discharge power neither overdrafts the health nor exceeds the physical remaining capacity, representing the maximum callable power that simultaneously satisfies both constraints.

[0038] In the direction of main energy storage discharge, the healthy available discharge power of the main energy storage The calculation formula is as follows: Among them, the first item Rated discharge power based on health factor The reduction result reflects the limitation of power capability by the health status; the second term Based on the current remaining available power during the scheduling period The maximum average power that can be released within, of which The amount of electricity that can be released when the current power level is higher than the safety lower limit. Discharge efficiency, used to account for the conversion relationship between charge and actual output power during discharge, divided by The releasable power is converted into the average power over the scheduling cycle. Discharge efficiency. The value of is determined based on the battery charge-discharge characteristic curve, and is typically between 0.9 and 0.95. The method for taking the smaller of the two values ​​is as follows: first, calculate the health reduction power and the allowable power at the energy boundary separately; then compare their magnitudes and output the smaller one as the main energy storage's healthy and usable discharge power. The advantage of taking the smaller value is that even if the battery is in good health, if the remaining charge is close to the safety lower limit, the output power will be automatically compressed to prevent over-discharge; conversely, even if the charge is sufficient, if the temperature is too high and the health coefficient decreases, the output power will be limited to prevent thermal runaway, thus protecting the energy storage simultaneously in terms of both power capability and energy boundary.

[0039] Regarding the main energy storage charging direction, the main energy storage has healthy and available charging power. The calculation formula is as follows: Among them, the first item Rated charging power based on health coefficient The reduction result; the second item This is the maximum average charging power calculated within the scheduling cycle based on the amount of electricity that can be absorbed between the current power level and the safe upper limit. To absorb electrical energy, Charging efficiency is placed in the denominator because the input power must be greater than the actual amount of electricity stored during charging. The value is determined based on the same criteria as the discharge efficiency, from the battery charge-discharge characteristic curve. Safety Upper Limit The setting is based on preventing overcharging and mitigating high voltage. Capacity decay under high voltage is determined by the charging cutoff conditions provided by the battery manufacturer. Taking the smaller of the two values ​​yields the healthy usable charging power of the main energy storage system. The healthy usable discharging power and the healthy usable charging power of the main energy storage system together constitute the healthy usable charging and discharging power of the main energy storage system. The advantage of taking the smaller value in the charging direction is that even if the rated charging power allows, if the battery level is close to the safe limit or the battery health is poor, the actual charging power will be compressed, avoiding overcharging and high voltage conditions. High-current charging accelerates aging.

[0040] The method for generating the available charge and discharge power for auxiliary energy storage is the same as that for main energy storage. That is, the auxiliary energy storage health coefficient is generated based on the degree to which the state of charge of the auxiliary energy storage deviates from the safe operating range, the charge and discharge rate status, and the degree to which the temperature status exceeds the reference temperature. Then, based on the auxiliary energy storage health coefficient, the rated charge and discharge capacity of the auxiliary energy storage is reduced, and the smaller value corresponding to the power safety boundary is taken to generate the auxiliary energy storage healthy usable discharge power and auxiliary energy storage healthy usable charging power. However, the parameter settings are different: since auxiliary energy storage (such as supercapacitors or fast-charging lithium batteries) is mainly used to smooth out short-term fluctuations in new energy sources, its design characteristics allow for higher rate capability and a wider temperature range, therefore its penalty coefficient is... Reference temperature The safe operating range can be individually calibrated according to the specific device specifications. For example, the rate penalty coefficient for supercapacitors can be lower than that for lithium batteries because they can withstand higher charge and discharge rates. The technical effect of separately calibrating the parameters of main and auxiliary energy storage is to match their respective healthy available power with their actual device characteristics, avoiding excessive constraints or over-utilization caused by uniform parameters. At the same time, it is clearly defined that main energy storage is prioritized for critical load assurance, while auxiliary energy storage is prioritized for smoothing fluctuations in new energy sources. This division of responsibilities ensures that the larger-capacity main energy storage undertakes the task of ensuring supply, while the faster-responding auxiliary energy storage undertakes the task of smoothing fluctuations, avoiding premature degradation caused by a single energy storage system undertaking all tasks.

[0041] The healthy and usable charging and discharging power output in this step will serve as a hard constraint boundary when generating power allocation instructions in subsequent steps, ensuring that scheduling instructions always fall within the physical domain where the equipment is safe and feasible. In this way, energy storage is no longer ideally called upon at its rated power, but participates in energy allocation within its actual healthy capacity range. This mechanism avoids excessive overdraft of energy storage under high temperature, high rate, and low power conditions, slows down capacity decay, and improves the long-term availability of energy storage.

[0042] Step 4: Based on the power supply reliability requirements of the loads in the microgrid, the loads are divided into critical load layers, general load layers, and interruptible load layers to form load protection priorities. Based on the current operating mode, load protection priorities, and healthy available charging and discharging power, power allocation instructions are generated under power balance constraints and issued to control the energy distribution of the microgrid.

[0043] Load stratification is the foundation for achieving differentiated supply assurance. The stratification is based on the power supply reliability requirements of the loads, i.e., the impact of power outages on personal safety, core business operations, and economic losses. In the island hospital scenario of this embodiment, the critical load stratification includes loads related to life safety and core business operations, such as operating rooms, ICUs, vaccine cold storage, and communication equipment rooms. These loads share the common characteristic that power outages would directly endanger life safety or cause irreversible losses, requiring uninterrupted power supply. The general load stratification includes loads that allow for short-term derating or delayed power supply, such as office lighting, air conditioning, and fresh air systems. Short-term power outages or derating of these loads only affect comfort and not safety, and can be drated or delayed when resources are scarce. The interruptible load stratification includes loads that can be cut off at any time without affecting core functions, such as electric vehicle charging stations, landscape lighting, and non-core processing equipment. These loads can be removed at any time and power restored after the risk is eliminated. The technical effect of layering according to power supply reliability requirements is that when resources are insufficient, the load shedding operation is carried out in reverse order of load importance from high to low. That is, interruptible load layer is cut off first, general load layer is derated, and critical load layer is always retained, so that limited power supply capacity is given priority to the most important load.

[0044] When generating power allocation instructions, instead of simply switching off loads according to priority, a continuous adjustment mechanism is introduced. Continuous adjustment is used because switching off causes abrupt power changes, easily leading to frequency and voltage fluctuations, while continuous adjustment allows loads to gradually withdraw as the risk increases. For interruptible load layers, a dynamic shelving ratio is defined. The calculation formula is as follows: In this formula, The off-grid risk index is normalized between the first and second risk thresholds, so that the cut-off ratio increases linearly with increasing risk; inner layer Guarantee when Below The cutoff ratio is not negative, meaning that interruptible loads are not cut off under economic operation mode; outer layer Guarantee when Exceed If the cutoff ratio does not exceed 1, the load can be completely cut off. This limit-limited linear form is used because the relationship between the cutoff ratio and risk needs to be monotonic and bounded; a linear mapping is intuitive and easy to calibrate, while avoiding abrupt changes. When the off-grid risk indicator... Between and In between, The interruptible load increases linearly from 0 to 1, meaning that as risk increases, the interruptible load is phased out gradually, rather than abruptly cut off entirely. The actual retention power of the interruptible load layer is... The power that was cut off was The technical advantage of this smooth transition mechanism is that it avoids system frequency oscillations or voltage drops caused by load step changes, improves the stability of the switching process, and minimizes the impact of the load shedding process on users.

[0045] Under power balance constraints, the healthy and available charging and discharging power of the main energy storage and the auxiliary energy storage are used as the boundaries for energy storage dispatch. Combined with the current operating mode and load guarantee priority, seven types of power allocation instructions are generated: grid-connected interface power instruction, diesel generator power instruction, main energy storage power instruction, auxiliary energy storage power instruction, general load shelving power instruction, interruptible load shelving power instruction, and energy curtailment power instruction. The reason for using healthy and available charging and discharging power as the boundary for energy storage dispatch is to limit the generated energy storage power within its actual healthy capacity range, avoiding dispatching energy storage based on rated capacity. The generation of these instructions is an interconnected process that must satisfy the supply and demand balance equation. The left side represents the total power supply from all sources, including photovoltaic power. Wind power output Diesel generator power output command Grid connection interface power command Main energy storage power command and auxiliary energy storage power command The right side represents the sum of the actual supplied load and the abandoned power, including the power of critical loads. General load power Subtract general load shedding power Interruptible load retains power Subtract interruptible load shedding power and curtailment power The equation is constructed in the form of supply equaling demand because power within the microgrid must be balanced in real time; otherwise, frequency deviations will occur. Therefore, the generation of any power allocation command must satisfy this constraint. (Energy storage power command) and The power allocation command must also fall within the range defined by the healthy available charging and discharging power calculated in step 3. Specifically, the main energy storage power command must lie between the negative value of the main energy storage's healthy available charging power and its healthy available discharging power. The same applies to auxiliary energy storage, ensuring that the allocated energy storage power never exceeds its true healthy capacity. The technical effect of this constraint is to ensure the physical feasibility of the power allocation command and prevent the generation of commands that exceed the power supply capacity or the energy storage's healthy capacity.

[0046] Under different operating modes, there are differentiated constraints on energy storage call boundaries and load shedding strategies. The logic behind setting these differentiated constraints is that the higher the risk, the higher the energy storage reservation requirements, and the greater the load shedding authority. Under the economic operation mode, the risk of off-grid operation is low, allowing primary energy storage to participate in economic charging and discharging adjustments, i.e., charging during off-peak hours and discharging during peak hours. At this time, the energy storage reserve requirement is minimal, and the load shedding authority is minimal; generally, no load is shelved. The reason for allowing energy storage to participate in economic regulation is that the system has sufficient reserve margin, and can reduce operating costs by utilizing peak-valley electricity price differences without affecting supply security.

[0047] In the enhanced resilience operation mode, the risk of off-grid access increases, so the main energy storage should be controlled to maintain reserved power, for example... The discharge depth should not be lower than a reserved threshold of 0.5, and the discharge depth of the main energy storage should be limited. The reserved threshold of 0.5 is set to reserve sufficient supply margin for possible off-grid events. Its specific value can be determined according to the critical load guarantee duration requirements and energy storage capacity. The reason for limiting the discharge depth and sacrificing some economic efficiency to buffer against potential risks is that if the energy storage is fully discharged according to economic targets at this time, it will be unable to support the critical load due to insufficient power once the risk evolves into actual off-grid. Therefore, reserving power in advance is a key measure to prevent the risk from escalating.

[0048] In anti-islanding operation mode, when the off-grid risk reaches its highest level, the main energy storage is prioritized to discharge to critical load layers, and economic charging of the main energy storage is stopped. Simultaneously, interruptible load layers are disconnected based on off-grid risk indicators, and diesel generators are activated as a backup power source if necessary. The reason for stopping economic charging is that charging under high-risk conditions would consume energy that could be used for power supply, and the external grid may disconnect at any time, making charging neither safe nor economical. Prioritizing the discharge of the main energy storage to critical load layers ensures that the most important loads can receive power under any circumstances. The diesel generators, as internal power sources unaffected by the external grid, are activated when the healthy and available discharge power of the energy storage is insufficient to support critical loads. Their output power is uniformly controlled by diesel generator power commands under power balance constraints, serving as a backup power source.

[0049] This example illustrates the power allocation process in an extremely high-risk scenario. When the system enters anti-islanding mode and the risk is extremely high, the charging pile loads belonging to the interruptible load layer are completely disconnected. Meanwhile, the operating rooms, which belong to the critical load layer, are always supplied with full power. If the main energy storage's available discharge power is insufficient to support the critical load, the system first automatically increases the output of the diesel generator to make up the shortfall. If it is still insufficient, the general load is reduced proportionally, but the critical load is never disconnected. The technical effect of this hierarchical and dynamically coupled allocation mechanism is that, under resource-constrained conditions, the power supply to the critical load is always prioritized, and the three types of regulation resources—energy storage, diesel, and load—are mobilized in an orderly manner, avoiding the chaos and power outages of critical loads caused by indiscriminate load shedding.

[0050] The generated seven types of power allocation commands are issued by the energy management system to the corresponding execution devices: diesel generator power commands are issued to the diesel generator controller; main energy storage power commands and auxiliary energy storage power commands are issued to the corresponding energy storage converters; grid connection interface power commands are issued to the grid connection point power regulation device; and general load shedding power commands, interruptible load shedding power commands, and curtailment power commands are issued to the load management unit for execution. Through the issuance and execution of these commands, this step translates the operating mode determined in step 2 and the healthy available charging and discharging power determined in step 3 into specific power control for each device, completing the energy allocation of the microgrid within the current dispatch cycle.

[0051] Step 5: In response to the off-grid risk indicators meeting the risk relief conditions, the recovery and recharging phase begins. The recharging is carried out in the order of priority restoration of the safe power boundary for the main energy storage and delayed restoration of the auxiliary energy storage. After the recovery exit conditions are met, the normal operation mode is restored.

[0052] The key difference between this approach and existing technologies lies in the fact that existing technologies often immediately restore economic dispatch after a fault, potentially leading to the main energy storage system encountering risks again before it has recovered to a safe level, leaving the system vulnerable to secondary risks. This approach employs a recovery strategy that prioritizes resilience over economic dispatch. That is, after the risk is resolved, the system does not immediately return to economic dispatch but instead prioritizes the recovery and recharging phase. First, the main energy storage is restored to the safe energy boundary required for the next risk event, then auxiliary energy storage is restored, and finally, normal operation is resumed only after the recovery exit conditions are met. The technical advantage of this arrangement is that it enables the system to quickly rebuild the energy storage safety boundary required for the next risk event after the risk event has ended, thus enhancing its ability to withstand secondary risks.

[0053] The triggering condition for the recovery and recharging phase is: when the churn event ends, or when the churn risk indicator falls below the second risk threshold. When the system's condition falls below the recovery threshold, it does not immediately switch back to economic mode but instead enters a recovery and recharge phase. The recovery threshold can be set to the same level as the first risk threshold. The same, or can be set slightly lower. The reason it can be slightly lower This is to introduce a certain lag between the exit from the recovery phase and the entry into the resilience-enhancing operation phase, to prevent risk indicators from... The system alternates between two phases during periods of minor fluctuation. The triggering conditions cover both the end of an off-grid event and a decline in risk indicators. This is to cover both the scenario of actual off-grid reconnection after an actual off-grid event and the scenario of increased risk without actual off-grid reconnection, ensuring that recharging can be triggered in both situations to rebuild the energy storage safety boundary.

[0054] During the recovery and recharging phase, priority is given to restoring the main energy storage. The current energy level and the safe target energy level of the main energy storage are obtained. and main energy storage health available charging power Main energy storage safety target capacity It is determined based on the critical load guarantee requirements, and the calculation formula is as follows: in, For the average power of critical load, To preset the protection duration, This serves as a safety margin (e.g., 5%) to account for forecasting errors. The safety target power level is determined based on the reserve capacity required for the next risk event, specifically tailored to the critical load's coverage duration. The required internal power supply is determined in conjunction with the main energy storage capacity, ensuring that the main energy storage can once it recovers to the target power level and resume its critical load supply tasks. There are three reasons for not fully charging: first, to reserve thermal buffer space and avoid accelerated aging due to prolonged full-charge and high-voltage conditions; second, to shorten recovery time and enable the system to quickly acquire secondary resilience; and third, considering the large fluctuations in renewable energy sources in island scenarios, reserving some capacity to absorb potential sudden photovoltaic surpluses and avoid energy curtailment. The technical effect of this setup is that it ensures the recovery of critical supply capabilities while avoiding battery degradation and recovery delays caused by blindly charging to full capacity.

[0055] Main energy storage recharge power This calculation is based on the current capacity of the main energy storage, the safe target capacity of the main energy storage, and the healthy available charging power of the main energy storage, following the principle of choosing the smaller of the target demand and the healthy capacity. The calculation formula is as follows: In this formula, the first term The second item is the main energy storage healthy usable charging power calculated in step 3, representing the upper limit of charging power allowed by the current health state of the battery; This is the target recharge power of the main energy storage, calculated by converting the difference in the amount of main energy storage awaiting recharge into the power required to complete the recharge within the scheduling cycle. The difference in the amount of main energy storage awaiting recharge is the difference between the safe target energy level of the main energy storage and the current energy level of the main energy storage. , Main energy storage charging efficiency. The scheduling cycle is used. The smaller of these two values ​​is chosen because if the battery is recharged at its healthy, available charging power when the target power demand is low, it will exceed the target capacity, causing overcharging. Conversely, if the battery is recharged at its target power demand when its health is insufficient, it will exceed the battery's capacity. Therefore, the smaller value ensures that the recharge process does not exceed the battery's current health capacity while filling the safety gap as quickly as possible. The auxiliary energy storage recharge power is generated in the same way, that is, the smaller of the auxiliary energy storage healthy, available charging power and the auxiliary energy storage target recharge power is determined as the auxiliary energy storage recharge power. The auxiliary energy storage target recharge power is calculated from the auxiliary energy storage pending recharge amount difference based on the auxiliary energy storage charging efficiency and the scheduling cycle. The auxiliary energy storage pending recharge amount difference is the difference between the auxiliary energy storage target capacity and the current auxiliary energy storage capacity.

[0056] Before the main energy storage reaches its safe target capacity, the auxiliary energy storage's recharge power is set to zero by default. Charging the auxiliary energy storage with remaining renewable power is only permitted when all of the following conditions are met: there is currently abandoned power. ,and (That is, the power curtailed is greater than the current actual recharge power command of the main energy storage); at this time, the power that the auxiliary energy storage can absorb is min( (k), If the power curtailment is insufficient to simultaneously support the recharging of both primary and auxiliary energy storage, then primary energy storage recharging will still be prioritized. Specifically, during each scheduling cycle of the recovery and recharging phase, it is determined whether the current power level of the primary energy storage has reached its safe target level. If not, the auxiliary energy storage recharging power is set to zero, concentrating all charging resources on primary energy storage recovery. Only when the current power level of the primary energy storage reaches its safe target level will auxiliary energy storage recharging power be generated and auxiliary energy storage recharging initiated. This sequential approach is adopted because primary energy storage bears the core responsibility of ensuring critical load supply, and its recovery priority is naturally higher than that of auxiliary energy storage used to mitigate new energy fluctuations. If both recharge simultaneously, it will disperse limited charging resources, delaying the time for primary energy storage to recover to the safe boundary, and keeping the system in a state of lacking critical supply capabilities for a longer period. The technical effect of this sequential arrangement is that limited charging resources are concentrated on rebuilding the system's most critical defense barrier, ensuring that critical supply capabilities are restored first.

[0057] Exiting the recovery and recharging phase requires meeting three conditions simultaneously: the current energy level of the main energy storage reaches the main energy storage safety target energy level, the current energy level of the auxiliary energy storage reaches the auxiliary energy storage target energy level, and the off-grid risk indicator remains below the recovery threshold for a set number of cycles. The reason for setting three conditions is that the power level condition confirms that both main and auxiliary energy storage have recovered to the target safety boundary, possessing the backup capacity to cope with the next risk; the risk indicator continuously falling below the recovery threshold confirms that the external environment has indeed stabilized, rather than a sudden drop in risk. (Set number of cycles) For example, if we take 6 cycles, a scheduling cycle of 5 minutes corresponds to 30 minutes. The design is based on striking a balance between preventing frequent mode switching and recovery speed. If the threshold is too small, the risk indicator will oscillate around the threshold, causing frequent mode switching. If the risk is too high, the system will remain in the recovery phase for too long, affecting the recovery of economic operations. During the recovery and recharging phase, priority will continue to be given to ensuring the supply of critical loads, so that the power supply to critical loads will not be affected throughout the entire recovery process. After exiting the recovery and recharging phase, the current operating mode will be redefined based on the off-grid risk indicators: if the risk indicator is below the first risk threshold, it will switch to the economic operation mode; if it is between the first and second risk thresholds, it will switch to the resilience enhancement operation mode. The technical effect of this exit mechanism is to avoid premature exit from recovery due to a temporary decline in risk, ensuring that the system resumes normal operation only after it has truly acquired the ability to withstand secondary risks.

[0058] After the power allocation command is issued and executed in step 4, or after exiting the recovery and recharging phase in step 5, the method in this embodiment further includes a rolling correction process. Rolling correction is implemented because the existence of prediction errors, device response delays, and measurement noise inevitably leads to deviations between the actual execution results and the theoretical commands. Without correction, these deviations can accumulate and cause the actual system state to continuously deviate from the expected state, potentially even leading to instability. Rolling correction feeds the execution deviations back into the power allocation of the next cycle, forming a closed-loop correction.

[0059] Specifically, at the end of a scheduling cycle, the actual power supplied by the microgrid is obtained. and actual load power Calculate the power balance deviation between the two. The reason for calculating the power balance deviation by subtracting the actual load power from the actual supplied power is that this deviation directly reflects the degree of imbalance between supply and demand during execution; a positive deviation indicates oversupply, and a negative deviation indicates undersupply. A balance threshold is set. This is used to determine whether calibration is needed. The reason for setting a threshold is that small deviations fall within the normal fluctuation range and do not require calibration, thus avoiding frequent adjustments. It can be set according to the normal fluctuation range of system power. When the power balance deviation exceeds the set balance threshold... At that time, the power compensation amount for the next scheduling cycle is generated based on the power balance deviation. ,in To compensate for gain. Proportional compensation is used because the amount of compensation is directly proportional to the magnitude of the deviation; the larger the deviation, the stronger the compensation. Furthermore, the compensation direction is consistent with the deviation direction, allowing for targeted elimination of imbalance. Gain compensation. It is a dimensionless proportionality coefficient, with a range of values ​​of 1000. Its setting should comprehensively consider the response time constants of the energy storage converter and the grid-connected inverter. and scheduling cycle Suggested initial values = And fine-tuning was performed through on-site step response tests: If the sign of the power balance deviation is reversed after compensation, then it decreases. If the deviation persists for more than 3 cycles, then increase the value. .final The system's response time to power deviation should not exceed [a certain value]. The power compensation is added to the power allocation command in the next scheduling cycle to achieve closed-loop correction of execution errors. The technical effect of this closed-loop correction is that the execution deviation in a single cycle is compensated in the next cycle, avoiding the accumulation of deviations and keeping the actual supplied power consistent with the expected target.

[0060] Simultaneously, at the end of each scheduling cycle, the off-grid risk indicators, current operating mode, healthy and available charging / discharging power of the main energy storage, and healthy and available charging / discharging power of the auxiliary energy storage are updated synchronously, allowing the microgrid to enter the next scheduling cycle. Specifically, in the next scheduling cycle, step 2 (generating off-grid risk indicators and determining operating mode) and step 3 (generating healthy and available charging / discharging power) are re-executed using the latest multi-source operating data, ensuring that the off-grid risk indicators, current operating mode, and healthy and available charging / discharging power all reflect the latest system state. The technical effect of this rolling update mechanism is to ensure that the control strategy is always based on the latest system state, enabling the method to adapt to load changes, energy storage temperature increases, and external grid disturbances, thus giving the method adaptive capability and robustness.

[0061] In summary, this embodiment achieves proactive defense by constructing multi-dimensional off-grid risk indicators, implements physical constraints for energy storage scheduling through healthy available power conversion, ensures precise supply of critical loads through load stratification and dynamic shelving, rapidly rebuilds system resilience through a recovery-priority recharge mechanism, and guarantees control accuracy through rolling correction. Compared with existing technologies, this solution significantly reduces the probability of power outages under sudden off-grid conditions, delays energy storage lifespan degradation, and enhances secondary risk resistance capabilities.

[0062] It should be understood that although this embodiment uses a microgrid in an island hospital as an example for detailed description, the scope of protection of this application is not limited thereto. For example, in a cold chain industrial park scenario, the critical load can be replaced by a cold storage compressor, the general load is the air conditioning in the office area, and the interruptible load is the forklift charging station; in a remote mining area scenario, the critical load is the ventilation and drainage equipment, the general load is the ore dressing equipment, and the interruptible load is the electricity used in the living area. The parameters in the formula (such as weighting coefficients, thresholds, target values) (etc.) can be recalibrated according to the actual equipment characteristics and scenario requirements without affecting the technical essence of this method. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the protection scope of this application. The above formulas are all dimensionless calculations. The formulas are derived from software simulations based on a large amount of collected data to obtain the most recent real-world results. The preset parameters in the formulas are set by those skilled in the art according to the actual situation.

[0063] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented in software, the above embodiments can be implemented, in whole or in part, as a computer program product. Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution.

[0064] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0065] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that cannot be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A hybrid microgrid energy distribution method considering energy storage operation constraints, the hybrid microgrid including energy storage units, the energy storage units including main energy storage and auxiliary energy storage, characterized in that, The methods include: Acquire multi-source operation data of the microgrid; Based on the changes in renewable energy output, external grid power intake status, energy storage reserve status, and grid stability status from multi-source operation data, the degree of renewable energy output fluctuation, external grid dependence, energy storage reserve insufficiency, and grid instability are generated respectively. Off-grid risk indicators are generated based on the degree of renewable energy output fluctuation, external grid dependence, energy storage reserve insufficiency, and grid instability. According to the risk level of the off-grid risk indicators, the current operation mode of the microgrid is determined as economic operation mode, resilience enhancement operation mode, or anti-islanding operation mode. Among them, economic operation mode, resilience enhancement operation mode, and anti-islanding operation mode correspond to different energy storage reservation requirements and load shedding permissions. Based on the degree to which the energy storage unit's state of charge deviates from the safe operating range, the degree to which its charge / discharge rate and temperature exceed the reference temperature, a healthy and usable charge / discharge power is generated, and this healthy and usable charge / discharge power is used as the boundary for the energy storage unit to participate in energy allocation. Based on the power supply reliability requirements of the loads in the microgrid, the loads are divided into critical load layers, general load layers and interruptible load layers to form load protection priorities. Based on the current operating mode, load protection priorities and healthy available charging and discharging power, power allocation instructions are generated under power balance constraints and issued to control the energy distribution of the microgrid. In response to the off-grid risk indicators meeting the risk relief conditions, the system enters the recovery and recharging phase. The recharging is carried out in the order of priority restoration of the safe power boundary for the main energy storage and delayed restoration of the auxiliary energy storage. After the recovery exit conditions are met, the system returns to normal operation mode.

2. The energy allocation method for a hybrid microgrid considering energy storage operation constraints according to claim 1, characterized in that, Based on the changes in renewable energy output, external grid power intake status, energy storage reserve status, and grid stability status from multi-source operational data, the following parameters are generated: renewable energy output fluctuation level, external grid dependence level, energy storage reserve insufficiency level, and grid instability level, including: The total output of renewable energy sources over the most recent scheduling cycles is obtained, and the degree of fluctuation of renewable energy output is generated based on the magnitude of change of the total output of renewable energy sources over the multiple scheduling cycles. The greater the magnitude of change, the higher the degree of fluctuation of renewable energy output. The power drawn by the microgrid from the external grid and the total load power of the microgrid are obtained, and the external grid dependence is generated based on the proportion of the power drawn from the external grid to the total load power. The higher the proportion, the higher the external grid dependence. The remaining available power of the main energy storage and auxiliary energy storage after deducting the safety lower limit is obtained, and the power required by the critical load within the set guarantee period is obtained. The energy storage reserve insufficiency is generated based on the comparison between the remaining available power and the required power. The more insufficient the remaining available power is relative to the required power, the higher the energy storage reserve insufficiency. The voltage fluctuation and frequency deviation at the microgrid grid connection point are obtained, and the grid instability is generated based on the voltage fluctuation and frequency deviation. The greater the voltage fluctuation and the greater the frequency deviation, the higher the grid instability. Off-grid risk indicators are generated based on the degree of fluctuation in new energy output, the degree of dependence on external power grid, the degree of insufficiency of energy storage reserves, and the degree of grid instability. The off-grid risk indicators are then compared with the first risk threshold and the second risk threshold. When the off-grid risk indicator is lower than the first risk threshold, the current operating mode will be determined as the economic operating mode. When the off-grid risk indicator is not lower than the first risk threshold and is lower than the second risk threshold, the current operation mode will be determined as the resilience-enhanced operation mode. When the off-network risk indicator is not lower than the second risk threshold, the current operating mode will be determined as the anti-islanding operating mode.

3. The energy allocation method for a hybrid microgrid considering energy storage operation constraints according to claim 2, characterized in that, Based on the degree to which the energy storage unit's state of charge deviates from its safe operating range, its charge / discharge rate status, and its temperature status exceeds the reference temperature, a healthy and usable charge / discharge power is generated, including: The state of charge, charge / discharge rate, and temperature of the main energy storage and the auxiliary energy storage are obtained respectively. A health coefficient for the main energy storage is generated based on the degree to which the energy state of the main energy storage deviates from the safe operating range, the charge / discharge rate represented by the charge / discharge rate state of the main energy storage, and the degree to which the temperature state of the main energy storage exceeds the reference temperature. An auxiliary energy storage health coefficient is generated based on the degree to which the state of charge of the auxiliary energy storage deviates from the safe operating range, the charge-discharge rate characterized by the charge-discharge rate of the auxiliary energy storage, and the degree to which the temperature of the auxiliary energy storage exceeds the reference temperature. The rated charge and discharge capacity of the main energy storage is reduced based on the main energy storage health coefficient to generate the main energy storage healthy usable charge and discharge power. The rated charge and discharge capacity of the auxiliary energy storage is reduced based on the auxiliary energy storage health coefficient to generate the healthy and usable charge and discharge power of the auxiliary energy storage. The healthy available charging and discharging power of the main energy storage and the healthy available charging and discharging power of the auxiliary energy storage are used together as the healthy available charging and discharging power.

4. The energy allocation method for a hybrid microgrid considering energy storage operation constraints according to claim 3, characterized in that, Based on the main energy storage health coefficient, the rated charge and discharge capacity of the main energy storage is reduced to generate the healthy and usable charge and discharge power of the main energy storage, including: In the direction of main energy storage discharge, the rated discharge power of the main energy storage is reduced based on the health coefficient of the main energy storage to obtain the reduced discharge power of the main energy storage. The allowable discharge power of the main energy storage is determined based on the amount of energy that can be released between the current energy level of the main energy storage and the safe lower limit energy level of the main energy storage, the discharge efficiency of the main energy storage, and the scheduling cycle. The smaller of the main energy storage reduced discharge power and the main energy storage allowable discharge power is determined as the main energy storage healthy available discharge power. In the direction of main energy storage charging, the rated charging power of the main energy storage is reduced based on the health coefficient of the main energy storage to obtain the reduced charging power of the main energy storage. The allowable charging power of the main energy storage is determined based on the amount of electricity that can be absorbed between the current energy capacity and the safe upper limit of the main energy storage, the charging efficiency of the main energy storage, and the scheduling cycle. The smaller of the main energy storage reduced charging power and the main energy storage allowed charging power is determined as the main energy storage healthy available charging power. The healthy available discharge power of the main energy storage and the healthy available charging power of the main energy storage together constitute the healthy available charging and discharging power of the main energy storage. The rated charge / discharge capacity of the auxiliary energy storage is reduced based on the auxiliary energy storage health coefficient to generate the healthy and usable charge / discharge power of the auxiliary energy storage, including: In the direction of auxiliary energy storage discharge, the rated discharge power of auxiliary energy storage is reduced based on the auxiliary energy storage health coefficient to obtain the reduced discharge power of auxiliary energy storage. The allowable discharge power of the auxiliary energy storage is determined based on the amount of energy that can be released between the current power of the auxiliary energy storage and the safe lower limit power of the auxiliary energy storage, the discharge efficiency of the auxiliary energy storage, and the scheduling cycle. The smaller of the auxiliary energy storage reduced discharge power and the auxiliary energy storage allowable discharge power is determined as the healthy available discharge power of the auxiliary energy storage. In the direction of auxiliary energy storage charging, the rated charging power of auxiliary energy storage is reduced based on the health coefficient of auxiliary energy storage to obtain the reduced charging power of auxiliary energy storage; The allowable charging power of the auxiliary energy storage is determined based on the amount of energy that can be absorbed between the current power of the auxiliary energy storage and the safe upper limit power of the auxiliary energy storage, the charging efficiency of the auxiliary energy storage, and the scheduling cycle. The smaller of the auxiliary energy storage reduced charging power and the auxiliary energy storage allowed charging power is determined as the healthy available charging power of the auxiliary energy storage. The healthy available discharge power of auxiliary energy storage and the healthy available charging power of auxiliary energy storage together constitute the healthy available charging and discharging power of auxiliary energy storage.

5. The energy allocation method for a hybrid microgrid considering energy storage operation constraints according to claim 4, characterized in that, Based on the current operating mode, load protection priority, and healthy available charging and discharging power, power allocation instructions are generated under power balance constraints, including: The critical load layer is set as the priority protection object, the general load layer is set as the object that can be reduced or delayed in power supply, and the interruptible load layer is set as the object that will be gradually withdrawn as the off-grid risk index increases. When the current operating mode is anti-islanding operating mode, interruptible load layers are disconnected first, while critical load layers are kept powered. Under power balance constraints, the healthy and available charging and discharging power of the main energy storage and the healthy and available charging and discharging power of the auxiliary energy storage are used as the energy storage call boundaries. Combined with the current operating mode and the power supply sequence of the critical load layer, general load layer and interruptible load layer, the grid connection interface power command, diesel generator power command, main energy storage power command, auxiliary energy storage power command, general load shelving power command, interruptible load shelving power command and energy curtailment power command are generated. When the current operating mode is the economic operating mode, the main energy storage is allowed to participate in economic charging and discharging adjustments; When the current operating mode is the resilience enhancement operating mode, the main energy storage is controlled to maintain reserved power and the discharge depth of the main energy storage is limited; When the current operating mode is the anti-islanding operating mode, the main energy storage is controlled to discharge to the critical load layer first, and the economic charging of the main energy storage is stopped. At the same time, the interruptible load layer is cut off according to the off-grid risk index. The grid connection interface power command, diesel generator power command, main energy storage power command, auxiliary energy storage power command, general load shedding power command, interruptible load shedding power command, and curtailment power command will be issued and executed as power allocation commands.

6. The energy allocation method for a hybrid microgrid considering energy storage operation constraints according to claim 5, characterized in that, The hybrid microgrid also includes diesel generators. When generating power distribution commands, diesel generator power commands are generated based on power balance constraints to control the output power of the diesel generators.

7. The energy allocation method for a hybrid microgrid considering energy storage operation constraints according to claim 6, characterized in that, In response to the off-grid risk indicators meeting the risk relief conditions, the system enters the recovery and recharging phase. Recharging is performed in the order of prioritizing the restoration of the main energy storage to the safe power boundary, with auxiliary energy storage restored later. This includes: When the churn event ends, or when the churn risk indicator falls from above the second risk threshold to below the recovery threshold, the recovery and recharge phase begins. During the recovery and recharging phase, obtain the current energy level of the main energy storage, the safe target energy level of the main energy storage, and the healthy available charging power of the main energy storage. Based on the current energy level of the main energy storage, the safe target energy level of the main energy storage, and the healthy available charging power of the main energy storage, the main energy storage recharge power is generated, and the main energy storage is controlled to charge according to the main energy storage recharge power. Before the main energy storage capacity reaches the main energy storage safety target capacity, the auxiliary energy storage recharge power will be kept at zero. Once the main energy storage reaches the main energy storage safety target, the current energy storage, the auxiliary energy storage target, and the auxiliary energy storage healthy and available charging power are obtained. Based on the current power level of the auxiliary energy storage, the target power level of the auxiliary energy storage, and the healthy available charging power of the auxiliary energy storage, the auxiliary energy storage recharge power is generated, and the auxiliary energy storage is controlled to charge according to the auxiliary energy storage recharge power.

8. The energy allocation method for a hybrid microgrid considering energy storage operation constraints according to claim 7, characterized in that, Based on the current capacity of the main energy storage, the safe target capacity of the main energy storage, and the healthy available charging power of the main energy storage, the main energy storage recharge power is generated, including: The difference between the main energy storage safety target capacity and the current capacity of the main energy storage is determined as the difference in the amount of main energy storage to be recharged. Based on the main energy storage charging efficiency and scheduling cycle, the difference in the amount of main energy storage waiting to be recharged is converted into the power required to complete the recharge within the scheduling cycle, which is used as the target recharge power of the main energy storage. The smaller of the main energy storage healthy available charging power and the main energy storage target recharge power is determined as the main energy storage recharge power. Based on the current auxiliary energy storage capacity, the target auxiliary energy storage capacity, and the healthy available charging power of the auxiliary energy storage, the auxiliary energy storage recharge power is generated, including: The difference between the target capacity of the auxiliary energy storage and the current capacity of the auxiliary energy storage is determined as the difference in the amount of auxiliary energy storage to be recharged. Based on the auxiliary energy storage charging efficiency and scheduling cycle, the difference in the amount of auxiliary energy storage waiting to be recharged is converted into the power required to complete the recharge within the scheduling cycle, which is used as the target recharge power of the auxiliary energy storage. The smaller of the auxiliary energy storage healthy available charging power and the auxiliary energy storage target recharge power is determined as the auxiliary energy storage recharge power.

9. The energy allocation method for a hybrid microgrid considering energy storage operation constraints according to claim 8, characterized in that, The target capacity for main energy storage safety is determined based on the backup capacity required for the next risk event, and the target capacity for main energy storage safety is lower than the full charge capacity. The target capacity of auxiliary energy storage is lower than the safe target capacity of main energy storage. During the recovery and recharge phase, priority will continue to be given to ensuring the critical load layer; When the current power of the main energy storage reaches the safety target power of the main energy storage, the current power of the auxiliary energy storage reaches the target power of the auxiliary energy storage, and the off-grid risk indicator continues to be lower than the recovery threshold for a set number of cycles, the recovery and recharging phase will be exited. After exiting the recovery and recharging phase, the current operating mode is redefined based on the off-grid risk indicators; After the power allocation command is issued and executed, or after exiting the recharge recovery phase, it also includes: After a scheduling cycle ends, obtain the actual power supplied and the actual load power of the microgrid. Calculate the power balance deviation between the actual supplied power and the actual load power; When the power balance deviation exceeds the set balance threshold, the power compensation amount for the next scheduling cycle is generated based on the power balance deviation. The power compensation amount is added to the power allocation instruction of the next scheduling cycle; Update off-grid risk indicators, current operating mode, healthy and available charging and discharging power of main energy storage and healthy and available charging and discharging power of auxiliary energy storage to enable the microgrid to enter the next dispatch cycle.

10. A hybrid microgrid energy distribution device considering energy storage operation constraints, characterized in that: The device is used to execute the hybrid microgrid energy distribution method considering energy storage operation constraints as described in any one of claims 1-9, including: The data acquisition module is used to acquire multi-source operational data of the microgrid; The output analysis module is used to generate the degree of new energy output fluctuation, external grid dependence, energy storage reserve insufficiency, and grid instability based on the changes in new energy output, external grid power intake status, energy storage reserve status, and grid stability status in multi-source operation data. Based on the degree of new energy output fluctuation, external grid dependence, energy storage reserve insufficiency, and grid instability, it generates off-grid risk indicators. According to the risk level of the off-grid risk indicators, it determines the current operation mode of the microgrid as economic operation mode, resilience enhancement operation mode, or anti-islanding operation mode. The economic operation mode, resilience enhancement operation mode, and anti-islanding operation mode correspond to different energy storage reservation requirements and load shedding permissions, respectively. The boundary generation module is used to generate healthy and usable charge and discharge power based on the degree to which the energy storage unit's state of charge deviates from the safe operating range, the charge and discharge rate status, and the degree to which the temperature status exceeds the reference temperature. The healthy and usable charge and discharge power is used as the call boundary for the energy storage unit to participate in energy allocation. The energy distribution module is used to divide the load into critical load layer, general load layer and interruptible load layer according to the power supply reliability requirements of the load in the microgrid, form load protection priority, and generate power distribution instructions under power balance constraints based on the current operating mode, load protection priority and healthy available charging and discharging power, and issue power distribution instructions to control the energy distribution of the microgrid. The operation control module is used to respond to the off-grid risk indicators meeting the risk relief conditions and enter the recovery and recharging phase. It performs recharging in the order of prioritizing the restoration of the safe power boundary of the main energy storage and delaying the restoration of the auxiliary energy storage, and resumes normal operation mode after meeting the recovery exit conditions.

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