A multi-bus optical storage micro-grid control system and method

Abstract

The present application belongs to the technical field of operation regulation and control of optical storage micro-grid, and discloses a multi-bus optical storage micro-grid control system and method. The control system comprises a multi-bus coupling loss perception module, an energy storage layered threshold correction module, a dynamic power compensation operation module and a steady-state deviation closed-loop suppression module. The multi-bus coupling loss perception module collects bus electrical operation parameters to generate a multi-bus dynamic coupling loss coefficient. The subsequent three types of modules sequentially complete energy storage threshold correction, global power compensation solution and steady-state parameter closed-loop adjustment in sequence based on the previous output parameters. The present application breaks the inherent architecture of existing single-bus discrete regulation and control and global unified energy storage threshold, and realizes the collaborative disposal of the three types of interference of coupling loss, energy storage working condition and source and load fluctuation through the step-by-step interaction of the data of the four layers of modules, thereby improving the inherent defects of circulating current superposition and energy storage layered imbalance under the multi-bus parallel operation condition.

Description

Technical Field

[0001] This invention belongs to the field of power operation and control technology of photovoltaic-storage microgrids, and discloses a multi-bus photovoltaic-storage microgrid control system and method. Background Technology

[0002] Currently, multi-bus architecture photovoltaic-storage microgrids generally adopt a control approach of independent management of a single bus. Various control strategies only perform static tuning for the load power within a single bus, without considering the electrical coupling effect caused by the cross-linking of equivalent impedances between branches of multiple buses. During parallel grid operation of multiple buses, voltage differences between buses induce cross-branch circulating currents. These circulating currents are superimposed on the inherent impedance losses of each branch, continuously increasing the overall power loss of the system. Energy storage devices are distributed across different bus locations. Existing control schemes configure uniform charging and discharging start-stop thresholds for all energy storage devices. Energy storage devices on buses with high losses are in a state of over-discharge for extended periods, while those on buses with low losses remain idle and unable to participate in power regulation, resulting in a stratified imbalance of energy storage resources. Under the dual conditions of random fluctuations in natural sunlight and instantaneous changes in bus load, existing control methods lack a tiered and progressive power correction logic. Power deviations accumulate over time, ultimately causing the bus-side voltage and frequency to deviate from the rated operating range. Existing optimization methods in the industry can only modify energy storage threshold parameters individually or supplement power for load fluctuations individually, and cannot simultaneously address the three types of problems: coupling loss, energy storage stratification, and dynamic power deviation.

[0003] Therefore, the market urgently needs a microgrid control scheme that can achieve multi-dimensional coordinated regulation. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and propose a multi-bus photovoltaic-storage microgrid control system, including a multi-bus coupling loss sensing module, an energy storage hierarchical threshold correction module, a dynamic power compensation calculation module, and a steady-state deviation closed-loop suppression module; the multi-bus coupling loss sensing module is used to collect the electrical operating parameters of each bus branch of the microgrid and calculate and output the multi-bus dynamic coupling loss coefficient.

[0005] The energy storage stratification threshold correction module is communicatively connected to the multi-bus coupling loss sensing module. It is used to receive the multi-bus dynamic coupling loss coefficient and, in combination with the operating parameters of each bus energy storage unit, correct the charge and discharge threshold of each bus energy storage unit.

[0006] The dynamic power compensation calculation module is communicatively connected to the energy storage hierarchical threshold correction module. It is used to receive the multi-bus dynamic coupling loss coefficient and the corrected charge and discharge threshold, and combine the microgrid source and load operating parameters to solve the global dynamic power compensation amount.

[0007] The steady-state deviation closed-loop suppression module is communicatively connected to the dynamic power compensation calculation module. It is used to receive the multi-bus dynamic coupling loss coefficient, the corrected charge and discharge threshold, and the global dynamic power compensation amount, calculate the steady-state balance correction coefficient, and adjust the microgrid electrical operating parameters according to the steady-state balance correction coefficient.

[0008] Preferably, the multi-bus coupling loss sensing module includes a high-precision power acquisition chip and a real-time computing logic unit; the high-precision power acquisition chip is used to acquire the operating current of the bus branch, the equivalent impedance of the branch, the reference voltage difference between the buses, and the rated operating power of the buses; the real-time computing logic unit is electrically connected to the high-precision power acquisition chip and is used to perform normalized loss calculation based on the electrical operating parameters acquired by the high-precision power acquisition chip, and output the multi-bus dynamic coupling loss coefficient.

[0009] More preferably, the energy storage stratified threshold correction module includes an energy storage parameter acquisition unit and a stratified correction calculation unit; the energy storage parameter acquisition unit is used to acquire the initial rated charge threshold, remaining available capacity, and rated total capacity of each bus energy storage unit; the stratified correction calculation unit is electrically connected to the energy storage parameter acquisition unit and the multi-bus coupling loss sensing module, and is used to independently complete the correction calculation of the charge threshold of a single bus energy storage unit based on the loss parameters of different buses.

[0010] More preferably, the dynamic power compensation calculation module includes a source-load parameter acquisition unit and a multi-condition collaborative calculation unit; the source-load parameter acquisition unit is used to acquire the real-time photovoltaic output power of the bus and the real-time load power consumption of the bus; the multi-condition collaborative calculation unit is electrically connected to the source-load parameter acquisition unit and the energy storage hierarchical threshold correction module, and is used to superimpose the branch coupling loss compensation dimension and the energy storage threshold deviation compensation dimension to calculate the global dynamic power compensation amount.

[0011] More preferably, the control system internally sets up four layers of sequentially connected data operation logic. The first layer of operation logic generates the multi-bus dynamic coupling loss coefficient based on the electrical parameters collected by the bus. The second layer of operation logic generates the corrected charge and discharge charge threshold based on the multi-bus dynamic coupling loss coefficient and the inherent parameters of energy storage. The third layer of operation logic generates the global dynamic power compensation amount based on the multi-bus dynamic coupling loss coefficient, the corrected charge and discharge charge threshold, and the source and load parameters. The fourth layer of operation logic generates the steady-state equilibrium correction coefficient based on the output parameters of the first three types of operation logic.

[0012] In a further preferred embodiment, the four layers of data operation logic have a fixed data flow direction, and all output parameters obtained from the previous layer are used as input parameters for the next layer of operation logic. Each layer of operation logic independently corresponds to an internal operation unit of a module. The four layers of operation logic are respectively deployed inside the multi-bus coupling loss sensing module, the energy storage stratification threshold correction module, the dynamic power compensation operation module, and the steady-state deviation closed-loop suppression module.

[0013] More preferably, the steady-state deviation closed-loop suppression module regulates the output power of the photovoltaic array, the charging and discharging rate of the energy storage unit, and the operating status of the multi-bus parallel circulating current; the steady-state deviation closed-loop suppression module completes the balanced regulation of the microgrid power, voltage, and frequency based on the steady-state balance correction coefficient.

[0014] More preferably, the multi-bus coupling loss sensing module, the energy storage stratification threshold correction module, the dynamic power compensation calculation module, and the steady-state deviation closed-loop suppression module complete data interaction and logical operations according to a fixed timing sequence, which is parameter acquisition, loss calculation, threshold correction, power compensation, and closed-loop correction in sequence.

[0015] A control method for a multi-bus photovoltaic-storage microgrid, applied to any of the multi-bus photovoltaic-storage microgrid control systems described above, wherein the method is executed by a microgrid controller and includes the following steps:

[0016] S1. The microgrid controller collects the branch operating current, equivalent impedance, bus reference voltage difference, rated operating power, real-time operating time and sampling period parameters of each bus of the microgrid through the multi-bus coupling loss sensing module.

[0017] S2. The microgrid controller calculates the multi-bus dynamic coupling loss coefficient based on the first-layer data operation logic, and transmits the multi-bus dynamic coupling loss coefficient to the energy storage layer threshold correction module.

[0018] S3. The microgrid controller collects the rated charge threshold, remaining capacity, rated capacity, real-time photovoltaic power and load power parameters of the energy storage unit through the energy storage hierarchical threshold correction module. Based on the second-layer data operation logic, it corrects the charge and discharge threshold of each bus energy storage unit one by one.

[0019] S4. The microgrid controller calculates the system-wide dynamic power compensation amount by relying on the third-layer data operation logic through the dynamic power compensation calculation module, combined with the multi-bus dynamic coupling loss coefficient and the corrected energy storage charge threshold.

[0020] S5. The microgrid controller calculates the steady-state equilibrium correction coefficient through the steady-state deviation closed-loop suppression module based on the fourth-layer data operation logic, and adjusts the microgrid operating parameters based on the steady-state equilibrium correction coefficient.

[0021] S6. The microgrid controller repeats all steps from S1 to S5 according to a fixed sampling period to complete the continuous parameter calculation and parameter adjustment of the microgrid.

[0022] More preferably, the method completes cyclic calculations based on a fixed sampling period, which matches the energy storage charging and discharging response time and the system parameter acquisition frequency; the method sequentially completes a fixed process of parameter acquisition, coefficient calculation, threshold correction, power compensation, and parameter adjustment, continuously updating the microgrid energy storage charging and discharging parameters, power compensation parameters, and steady-state equilibrium parameters.

[0023] The technical effects include:

[0024] This invention, based on a four-layer functional module architecture with hierarchical data interaction, specifically addresses the core issues described in the background technology, such as the inability to quantify multi-bus cross-linking coupling losses, the hierarchical imbalance caused by a uniform threshold across the entire energy storage domain, and the lack of progressive power compensation for source-load fluctuations. The multi-bus coupling loss sensing module first quantifies the loss data formed by impedance coupling between buses. Subsequent modules then modify the energy storage start-up and shutdown thresholds of each bus based on the loss data, and calculate the compensation power in conjunction with source-load parameters. Finally, a closed-loop fine-tuning of the grid operating parameters is achieved using a steady-state equilibrium correction coefficient. This integrates the handling of three types of problems—coupling loss control, energy storage resource allocation, and power deviation suppression—avoiding the limitations of existing single-dimensional optimization methods. Attached Figure Description

[0025] Figure 1 A block diagram showing the module hierarchy of a multi-bus coupling loss sensing energy storage and control system.

[0026] Figure 2 The flowchart shows a microgrid energy storage control method based on multi-bus coupling losses.

[0027] Figure 3 This is a swimlane diagram showing the time-sharing collaborative operation of the four functional modules under a single sampling period. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0029] Please see Figures 1-3This embodiment provides a multi-bus photovoltaic-storage microgrid control system, including: a multi-bus coupling loss sensing module, an energy storage hierarchical threshold correction module, a dynamic power compensation calculation module, and a steady-state deviation closed-loop suppression module. These four modules complete data interaction and logical operations according to a fixed time sequence, with data being transmitted unidirectionally between modules via communication links. The multi-bus coupling loss sensing module, as the data starting point of the entire system, collects various raw electrical data from the physical bus lines and converts them into multi-bus dynamic coupling loss coefficients, which serve as the common reference input data for all subsequent modules. After receiving the multi-bus dynamic coupling loss coefficients via the communication link, the energy storage hierarchical threshold correction module adjusts the charging and discharging thresholds of the energy storage configured on that bus based on its own loss value. The dynamic power compensation calculation module simultaneously summarizes the multi-bus dynamic coupling loss coefficients, the modified threshold data for energy storage, and the real-time power consumption data of the photovoltaic system and loads, comprehensively calculating the required global dynamic power compensation based on multiple variables. The steady-state deviation closed-loop suppression module summarizes all the output results of the first three modules and calculates the steady-state equilibrium correction coefficient for fine-tuning the power grid operating conditions. Based on the steady-state equilibrium correction coefficient, the electrical parameters on the bus side are adjusted in reverse. The entire module forms a complete closed-loop link from raw data acquisition to end-point electrical parameter adjustment.

[0030] The multi-bus coupling loss sensing module serves as the data starting point for the entire system, collecting electrical operating parameters of each bus branch in the microgrid and calculating and outputting the multi-bus dynamic coupling loss coefficient. The multi-bus coupling loss sensing module includes a high-precision power acquisition chip and a real-time processing logic unit. The high-precision power acquisition chip, as the hardware acquisition carrier, directly connects to the voltage and current acquisition terminals of each bus in the microgrid, capturing four types of basic electrical data: bus branch operating current, branch equivalent impedance, inter-bus reference voltage difference, and bus rated operating power. The bus branch operating current is obtained through a current transformer; the branch equivalent impedance is calculated by injecting a small signal to measure the phase difference between the bus terminal voltage and current; the inter-bus reference voltage difference is directly measured through the voltage sampling terminals of the parallel buses; and the bus rated operating power is entered into the system after referring to the parameters on the bus's manufacturer's nameplate. All collected raw electrical data is transmitted to the back-end real-time processing logic unit via electrical lines. The real-time computing logic unit is equipped with a normalized data processing program. After receiving all the raw parameters from the front-end chip, it performs loss normalization calculations based on the bus rated power, and finally outputs the multi-bus dynamic coupling loss coefficients that can be used by subsequent modules. The hardware acquisition and logic operation are set up separately, allowing for individual replacement of faulty acquisition chips or upgrading of internal computing logic without replacing the entire sensing module. This separate unit architecture separates the acquisition and processing steps, ensuring independent controllability of raw data acquisition accuracy and loss coefficient conversion.

[0031] The multi-bus coupling loss sensing module internally deploys the first-layer data processing logic. This first-layer logic generates the multi-bus dynamic coupling loss coefficient based on the electrical parameters collected from the buses. All input data for this first-layer logic consists of the raw electrical parameters collected on-site from the buses, and the sole output is the multi-bus dynamic coupling loss coefficient. The corresponding calculation formula for this first-layer logic is as follows:

[0032] ;

[0033] This formula is used for loss coefficient conversion within the first-level data processing logic. N represents the total number of operating buses in the microgrid, a dimensionless count value equal to the total number of buses operating in parallel in the system. I is the real-time operating current of the i-th bus branch, in amperes. This current value is directly measured from the bus branch using a high-precision power acquisition chip, and the measurement time is the instantaneous value at the start of the system's parameter acquisition process. Z is the equivalent impedance of the i-th bus branch, in ohms. This impedance value is calculated by injecting a small-amplitude AC signal of known frequency into the bus branch, measuring the phase difference between the branch's terminal voltage and the flowing current, and then applying Ohm's law. ΔU is the real-time voltage difference between the i-th bus and the reference bus, in volts. This voltage difference is obtained by directly measuring the amplified difference between the voltage sampling signal of the i-th bus and the voltage sampling signal of a pre-specified reference bus after feeding them into a differential amplifier. P represents the rated operating power of the i-th bus, measured in watts. This value is obtained from the bus's manufacturer's technical specifications and is usually marked on the bus equipment's nameplate. T represents the system's real-time operating time, measured in seconds. This time is read from a timer within the control system, which begins accumulating counts upon the system's initial power-on and continuously updates the accumulated value. T represents the system sampling period, measured in seconds. This period is selected based on a combination of the shortest acquisition interval of the hardware acquisition chip and the longest response interval of the energy storage converter, and is stored as a fixed parameter within the controller.

[0034] The calculation process of the formula starts from the basic theory of power loss. The total loss of a single bus branch is divided into two components: impedance heating loss and circulating current loss caused by the voltage difference across the bus. Impedance heating loss follows Joule's law; when current flows through a conductor with resistance, electrical energy is converted into heat energy, and its instantaneous power is equal to the square of the current multiplied by the resistance, expressed as I multiplied by Z. The circulating current loss caused by the voltage difference stems from the unequal voltage between two parallel buses. The bus with the higher voltage will supply circulating current to the bus with the lower voltage. When this circulating current flows through the bus impedance, it will also generate power loss. This power loss is approximately equal to the voltage difference multiplied by the current, expressed as ΔU multiplied by I. The sum of the two types of power yields the total coupling loss power of the i-th branch under the current operating conditions. The rated power P of the bus in the denominator is used to normalize the loss power, eliminating numerical deviations caused by inconsistencies in the rated power of different buses. The rated power of a busbar is the maximum power allowed for long-term operation during the busbar's design. Different busbars may have significantly different rated power due to variations in wire diameter, material, and length. Directly using the absolute value of power loss makes it impossible to uniformly compare the severity of losses across the entire system. Therefore, it is necessary to divide by the respective rated power to convert the power loss into a dimensionless ratio relative to the rated power. Duration correction item. The system's actual continuous operating time and the fixed sampling period of the equipment are not equal. The real-time operating time T may be much longer than the sampling period T. The loss coefficient needs to reflect the cumulative effect of long-term operation at the current control moment. Therefore, a dynamic correction is performed using the square root of the time-to-time ratio. The square root operation causes the correction amplitude to increase with time, but the rate of increase gradually slows down to avoid over-correction in short-term operation or under-correction in long-term operation. Finally, the arithmetic mean of the loss coefficients of all buses is calculated based on the total number of buses N, resulting in a globally unified multi-bus dynamic coupling loss coefficient φ.

[0035] Taking a photovoltaic-storage microgrid with 8 buses as an example, the measured current, impedance, and voltage difference parameters of each bus are recorded one by one. Assume the measured branch operating current of the first bus is I = 120A, the equivalent impedance is Z = 0.05Ω, the voltage difference with the reference bus is ΔU = 2.2V, and the rated operating power is P = 50kW. The system's real-time operating time is T = 3600s, and the sampling period is T = 60s. The loss factor for this bus is calculated as follows: impedance heating loss power I multiplied by Z equals 14400 multiplied by 0.05 equals 720W; circulating current loss power ΔU multiplied by I equals 2.2 multiplied by 120 equals 264W; the sum of these two equals 984W; dividing by the rated power of 50000W gives 0.01968; multiplying by the duration correction term... equal The value is approximately 7.746, resulting in a loss coefficient of approximately 0.1524 for this bus. The loss coefficients of the remaining seven buses are calculated using the same method, and their arithmetic mean is taken to obtain the global loss coefficient φ. This value is directly used as the input parameter for the second-level operational logic.

[0036] The energy storage tiered threshold correction module communicates with the multi-bus coupling loss sensing module to receive the dynamic coupling loss coefficient of the multi-bus system. Combined with the operating parameters of each bus energy storage unit, it corrects the charge and discharge thresholds of each bus energy storage unit. The energy storage tiered threshold correction module includes an energy storage parameter acquisition unit and a tiered correction calculation unit. The energy storage parameter acquisition unit interfaces with the sampling port of the battery management system configured for energy storage on each bus, collecting three types of inherent parameters of the energy storage unit: initial rated charge threshold, remaining usable capacity, and rated total capacity. The initial rated charge threshold is determined by the factory parameters of the energy storage battery, representing the default charging and discharging cutoff thresholds set by the battery management system. Typically, the charging cutoff threshold is set to 90% to 95% of the battery capacity, and the discharging cutoff threshold is set to 10% to 20%. The remaining usable capacity is estimated by the battery management system using the ampere-hour integration method or Kalman filter algorithm after monitoring the battery voltage, current, and temperature; the unit is joules. The rated total capacity is directly provided by the factory nameplate parameters of the energy storage battery; the unit is joules. The collected raw energy storage parameters are synchronously transmitted to the hierarchical correction calculation unit within the same module. This unit additionally receives the multi-bus dynamic coupling loss coefficients output from the multi-bus coupling loss sensing module via electrical wiring. The hierarchical correction calculation unit independently calculates the loss coefficient for each bus. If the loss value of a single bus is too high, the energy storage discharge threshold for that bus is lowered; if the loss value is too low, the energy storage charging threshold is raised. Threshold revision is performed individually for each bus, abandoning the management method of using a single threshold for the entire system. The parameter acquisition and threshold correction units are deployed separately, ensuring that the raw energy storage capacity data does not directly participate in calculations other than threshold conversion. This dual-unit split design enables separate input of raw energy storage parameters and loss parameters, allowing for independent tuning of the energy storage threshold for each bus.

[0037] The energy storage tiered threshold correction module internally deploys a second-layer data processing logic. This second-layer logic generates corrected charge and discharge charge thresholds based on the multi-bus dynamic coupling loss coefficient and inherent energy storage parameters. The input data for this second-layer logic includes the multi-bus dynamic coupling loss coefficient output from the first layer and the inherent energy storage parameters acquired by the energy storage parameter acquisition unit. The output is the corrected charge and discharge charge thresholds for each bus. The corresponding calculation formula for the second-layer logic is as follows:

[0038]

[0039] This formula is used within the second-layer data operation logic to revise the charge and discharge thresholds of the energy storage unit on a bus-by-bus basis. S is the layered correction charge threshold for the energy storage unit, a dimensionless value representing the corrected state of charge (S) for charging or discharging. S is the initial rated charge threshold for the energy storage unit, dimensionless, determined by the battery's factory parameters, usually given as a percentage. For example, a charging cutoff threshold of 0.95 means stopping charging when the battery's state of charge reaches 95%. α is the loss adaptation correction constant, dimensionless, obtained through offline experimental calibration. The calibration method involves selecting a test bus and testing the correction threshold that maximizes the energy storage system's operating efficiency under different loss coefficients. Multiple sets of test data are then curve-fitted to obtain an empirical value for α, typically ranging from 0.2 to 0.8. φ is the multi-bus dynamic coupling loss coefficient of the first-layer output, dimensionless. E is the remaining usable capacity of the energy storage unit, in Joules, estimated in real-time by the battery management system. E is the rated total capacity of the energy storage unit, in Joules, obtained from the battery's nameplate. P represents the real-time photovoltaic output power of the bus, measured in watts, and is obtained in real-time through a power sensor at the output measurement point of the photovoltaic inverter. P also represents the real-time load power consumption of the bus, measured in watts, and is obtained in real-time through a power sensor at the load input measurement point of the bus.

[0040] The formula is broken down into two independent correction terms. The first term, S, multiplied by 1 (within parentheses) minus α multiplied by φ, is used to revise the loss-related threshold. Using the factory-rated threshold S as the base value, the base value is corrected in reverse based on the loss coefficient φ output from the first layer. The larger the loss coefficient φ, the more severe the coupling loss of the bus. In this case, the energy storage discharge threshold needs to be lowered to allow the energy storage to release power to the bus earlier, reducing the need to draw power from high-loss buses. α is a fixed calibration constant used to constrain the correction range of the loss on the threshold, avoiding over-correction that leads to frequent charging and discharging of the energy storage. When φ equals 0, the first term equals S, and no correction is performed; when φ is greater than 0 and α multiplied by φ is less than 1, the first term is less than S, and a downward adjustment is performed. The second term... It is used to match the fluctuations in source load power with changes in the remaining energy storage capacity. This is the ratio of remaining energy storage capacity to rated capacity. This ratio is dimensionless and reflects the current abundance of remaining energy in the energy storage system. This is the power ratio of photovoltaic (PV) output to load power consumption. This ratio is dimensionless; it is greater than 1 when PV output exceeds load consumption, and less than 1 when PV output is less than load consumption. (Logarithmic operation) Used to map power ratios to logarithmic coordinates, the logarithmic function has the characteristic of compressing large values ​​and amplifying small values ​​close to zero, which can avoid drastic threshold jumps caused by sudden changes in source load power. The overall relationship between the rear sub-terms and... Multiplying together, the more abundant the remaining capacity and the greater the relative output of photovoltaic power compared to the load, the greater the positive correction value contributed by the subsequent sub-items. Appropriately raising the charging threshold allows energy storage to reserve more capacity to absorb surplus photovoltaic power.

[0041] Based on the threshold tuning theory of energy storage battery management systems, the rated threshold is jointly affected by three factors: line loss, remaining capacity, and source-load supply and demand. Line loss is represented by φ in the preceding sub-item, and remaining capacity is represented by... This reflects the supply and demand of energy sources and loads. This formula breaks down the three influencing factors into two sub-items, corrects them separately, and then sums them. Both sub-items are dimensionless operations, and the output S after summing also remains dimensionless. An example is taken using two buses with different loss coefficients. Assume the loss coefficient of bus A is φ=0.15, the loss coefficient of bus B is φ=0.03, the initial rated charging threshold of energy storage is S=0.90, and the loss adaptation constant is α=0.5. The first sub-item of bus A is 0.90 multiplied by 1 minus 0.5 multiplied by 0.15, which equals 0.90 multiplied by 0.925, equaling 0.8325. The first sub-item of bus B is 0.90 multiplied by 1 minus 0.5 multiplied by 0.03, which equals 0.90 multiplied by 0.985, equaling 0.8865. Further assume the remaining energy storage capacity of the two buses is E=50000kJ, the rated total capacity is E=100000kJ, and E / E=0.5. Photovoltaic power P = 80kW, load power P = 50kW, P / P = 1.6. The latter part is 0.5 multiplied by 0.9555, which equals 0.47775. The corrected charging threshold for bus A is 0.8325 plus 0.47775, which equals 1.31025. Since the upper limit of the charge threshold is 1, it is actually taken as 1.0. The corrected charging threshold for bus B is 0.8865 plus 0.47775, which equals 1.36425, and it is also taken as 1.0. The charging thresholds of both buses are corrected to 100%, but because bus A has higher losses, its front part is compressed to a lower value, making the contribution of the rear part required to reach the full charge threshold greater. This reflects the physical requirement that high-loss buses need to make fuller use of energy storage charging capacity.

[0042] The dynamic power compensation calculation module communicates with the energy storage stratified threshold correction module to receive the dynamic coupling loss coefficients of multiple buses and the corrected charge / discharge thresholds. Combined with the microgrid source-load operating parameters, it calculates the overall dynamic power compensation. The dynamic power compensation calculation module includes a source-load parameter acquisition unit and a multi-condition collaborative calculation unit. The source-load parameter acquisition unit connects to the output measurement points of the photovoltaic inverter and the input measurement points of the bus load, continuously collecting two types of source-load operating data: real-time photovoltaic output power and real-time load power consumption. Photovoltaic output power is obtained through the power measurement circuit inside the photovoltaic inverter, which monitors the DC-side voltage and current or the AC-side output voltage and current in real time before calculating the power value. Load power consumption is obtained through a power sensor installed at the bus load input. This sensor can use the Hall effect principle or the resistive voltage division principle to measure voltage and current before calculating active power. The collected data is sent to the multi-condition collaborative calculation unit in the same module. The multi-condition collaborative calculation unit simultaneously receives the dynamic coupling loss coefficients of multiple buses and the corrected charge / discharge thresholds from the preceding modules. The multi-condition collaborative computing unit internally splits into two independent calculation dimensions. The first dimension calculates the compensation power required to make up for the circulating current loss based on the coupling loss value. The second dimension calculates the compensation power that the energy storage can support based on the available energy storage margin brought about by the change in the energy storage threshold. The calculation values ​​of the two dimensions are combined to obtain the final global dynamic power compensation amount, breaking the single calculation mode of calculating compensation power solely based on load data. Source load acquisition and multi-dimensional power calculation are set as separate units, and the calculation rules of the two types of compensation dimensions can be adjusted independently.

[0043] The dynamic power compensation calculation module internally deploys a third-layer data processing logic. This third-layer logic generates the global dynamic power compensation amount based on the multi-bus dynamic coupling loss coefficient, the corrected charge / discharge threshold, and source / load parameters. The input to this third-layer logic includes the output data from the first two layers plus the photovoltaic and load power data collected by the source / load parameter acquisition unit; the output is the global dynamic power compensation amount. The corresponding calculation formula for the third-layer logic is as follows:

[0044] ;

[0045] This formula is used in the third-layer data processing logic to calculate the compensation power required for the entire system. ΔP is the system dynamic power compensation amount, in watts, representing the power injected from the energy storage system or external grid into the microgrid under current operating conditions to maintain stable bus voltage and frequency. β is the power compensation proportionality constant, dimensionless, determined through offline system simulation or field test calibration. The calibration method involves measuring the ratio between the actual power loss and the calculated value of φ multiplied by P under standard operating conditions, taking the average of multiple tests as β, typically ranging from 0.8 to 1.2. φ is the multi-bus dynamic coupling loss coefficient output from the first layer, dimensionless. P is the total rated power of the microgrid system, in watts, equal to the sum of the rated power of all buses, obtained from the technical parameter tables of each bus and then summed. S is the initial rated charge threshold of the energy storage, dimensionless. S is the corrected energy storage threshold output from the second layer, dimensionless; the difference between S and S indicates the degree to which the energy storage threshold has been modified. E represents the rated total capacity of energy storage, in joules. T represents the energy storage charge / discharge response time, in seconds. This parameter is determined by the hardware response characteristics of the energy storage converter and represents the time required for the energy storage system to output the corresponding power from receiving a power command. It can be obtained by measuring the step response time of the energy storage converter. P represents the real-time photovoltaic output power of the bus, in watts. P represents the real-time load power consumption of the bus, in watts. P represents the total rated power of the system, in watts.

[0046] The formula is divided into two main components: loss compensation and energy storage margin compensation. The first component, β multiplied by φ multiplied by P, is used to compensate for the power gap corresponding to bus coupling losses. φ is the global loss coefficient, and P is the total rated power of the system. Their product gives an estimated loss power value that is proportional to the rated capacity of the system. This estimate is based on the assumption that there is a linear proportional relationship between the loss power and the total system capacity, with a proportionality coefficient of φ. Since the actual loss may deviate from this linear estimate, β is introduced as a correction factor. Offline calibration is used to make β multiplied by φ multiplied by P as close as possible to the actual measured loss power. The output of this component is in watts, representing the power that needs to be injected into the system to compensate for bus coupling losses.

[0047] Second item This represents the compensation power corresponding to the adjustable energy storage margin. (SS) represents the dimensionless energy storage power margin after the energy storage threshold is modified. S is the original charging threshold, and S is the corrected charging threshold. When S is greater than S, SS is negative, indicating that the energy storage charging threshold has been raised and more capacity has been reserved for absorbing power. When S is less than S, SS is positive, indicating that the energy storage discharging threshold has been lowered and the energy storage can contribute more discharging power. Dividing the rated energy storage capacity by the response time, and then dividing the joules by the seconds, yields the watts. Watts represent the average power that the energy storage system can release or absorb within the response time, reflecting the system's power output capability. (Exponential term) This is used to suppress overshoot of compensation power caused by excessive difference between photovoltaic (PV) and load power. When the PV output power P is greater than the load power P, PP is positive, and the exponent term e raised to the power of a negative positive number is a positive number less than 1, automatically reducing the compensation amount to prevent the system from requiring energy storage to discharge even when PV power is surplus. When the PV output power P is less than the load power P, PP is negative, and the exponent term e raised to the power of a negative negative number is equal to the power of e raised to the power of a positive number, resulting in a number greater than 1, amplifying the compensation amount to reflect the physical demand for more compensation when the load is short of power. The decay characteristic of the exponential function ensures that the adjustment of the compensation amount changes smoothly with the increase of the power difference, without any abrupt changes.

[0048] Based on power balance theory, the system's power deficit is supplemented by two sources: line losses and available energy storage capacity. The first term compensates for the power gap corresponding to the losses, while the second term utilizes the power margin released after adjusting the energy storage threshold. Both terms are converted to watts, and after addition, ΔP remains in watts, ensuring dimensional uniformity across the entire formula. Taking the values ​​from the aforementioned embodiment as an example, we substitute them into this formula for calculation. Assuming the multi-bus dynamic coupling loss coefficient φ = 0.12, the total rated power of the system P = 400kW, and the power compensation proportional constant β = 1.0, then the first term is 1.0 multiplied by 0.12 multiplied by 400kW, which equals 48kW. Further assuming the original energy storage charging threshold S = 0.90, the corrected charging threshold S = 1.0, SS = -0.10, the rated total energy storage capacity E = 500,000kJ, and the energy storage charging and discharging response time T = 2s, then... =250000kW, this value is far greater than the actual power demand of the microgrid. In actual use, the capacity term needs to be limited to ensure that its maximum output does not exceed the rated power of the energy storage converter. To avoid calculation overflow due to excessively large values, in actual engineering implementation, E / T is replaced with the rated power P of the energy storage converter, which is taken as P=100kW here. In the exponent terms, P=80kW, P=50kW, PP=30kW, P=400kW. , The second term is (-0.10) multiplied by 100kW multiplied by 0.9277, which equals -9.277kW. A negative value indicates that the energy storage system does not need discharge compensation at this point, but instead needs to absorb power through charging. Adding the two terms together gives ΔP = 48kW, plus the negative 9.277kW (in parentheses), which equals 38.723kW. This means the system needs to receive 38.723kW of power from an external source. If PP is negative, assuming P = 50kW and P = 80kW, the difference is -30kW. , The second term is (-0.10) multiplied by 100kW multiplied by 1.0779, which equals -10.779kW. Adding this to the first term of 48kW gives 37.221kW. The compensation amount decreases slightly but is still positive because loss compensation is dominant.

[0049] The steady-state deviation closed-loop suppression module communicates with the dynamic power compensation calculation module. It receives the multi-bus dynamic coupling loss coefficient, the corrected charge / discharge threshold, and the global dynamic power compensation amount. It then calculates the steady-state equilibrium correction coefficient and adjusts the microgrid's electrical operating parameters based on this coefficient. The steady-state deviation closed-loop suppression module regulates the photovoltaic array output power, the energy storage unit's charge / discharge rate, and the multi-bus parallel circulating current operation status. The module interfaces with three types of actuators: the photovoltaic array controller, the energy storage converter, and the bus parallel switch. These three types of actuators correspond to the photovoltaic array output power, the energy storage unit's charge / discharge rate, and the multi-bus parallel circulating current operation status, respectively. After generating the steady-state equilibrium correction coefficient, the module sends adjustment commands to the three types of controllers according to the coefficient values. This changes the output power of the photovoltaic array, the charge / discharge start / stop rate of the energy storage converter, and the switching status of the bus parallel switch. After the three electrical parameters are adjusted synchronously, the bus-side power, voltage, and frequency indicators return to their rated range. The three types of regulation targets correspond to three key equipment categories in the microgrid: the power generation side, the energy storage side, and the bus interconnection side. The regulation points fully cover the entire link of power generation, power storage, and bus interconnection in a multi-bus system. The steady-state deviation closed-loop suppression module completes the balanced regulation of power, voltage, and frequency of the microgrid based on the steady-state equilibrium correction coefficient.

[0050] The steady-state deviation closed-loop suppression module internally deploys a fourth layer of data processing logic. This fourth layer generates steady-state equilibrium correction coefficients based on the output parameters of the first three layers. The input to this fourth layer includes all output parameters from the first three layers, and the output is the steady-state equilibrium correction coefficients. The corresponding calculation formula for this fourth layer is as follows:

[0051]

[0052] This formula is used in the fourth-layer data processing logic to generate the steady-state equilibrium correction coefficient for final closed-loop regulation. η is the system steady-state equilibrium correction coefficient, dimensionless, which serves as the reference value for commands sent to the photovoltaic array controller, energy storage converter, and bus parallel switch. A coefficient close to 1 indicates that the current operating state is close to the ideal equilibrium state, and the adjustment range should be small; the further the coefficient deviates from 1, the larger the deviation, and the larger the adjustment range should be. ΔP is the dynamic power compensation output from the third-layer formula, in watts. P is the total rated power of the system, in watts. φ is the multi-bus dynamic coupling loss coefficient output from the first layer, dimensionless. S is the corrected energy storage threshold output from the second layer, dimensionless. S is the initial rated charge threshold of the energy storage, dimensionless.

[0053] The formula as a whole consists of the product of three sets of dimensionless terms in sequence. The first term... This is a normalized ratio of compensation power to the total rated power of the system. The numerator ΔP represents the power that needs to be injected from the outside, and the denominator P represents the maximum power that the system can withstand. The ratio of the two reflects the relative severity of the power shortfall. When ΔP is close to 0, this ratio is close to 0, and η approaches 0, indicating that the system does not require adjustment. When ΔP and P are of the same order of magnitude, this ratio is close to 1, and η approaches the product of the other two terms, indicating that the system requires significant adjustment. Both the numerator and denominator are in the dimension of watts, while the ratio is dimensionless.

[0054] Second item Attenuation correction is based on the loss factor. The multi-bus dynamic coupling loss factor φ reflects the degree of energy loss between buses due to impedance mismatch and voltage difference. The larger φ is, the more severe the internal loss of the system. If the adjustment is still based on the power compensation ratio, it may cause the adjustment on high-loss buses to be too drastic, which may exacerbate the loss. Therefore, 1 is added to the denominator to make the attenuation factor... As φ increases from 0 to infinity, the second term monotonically decreases from 1 to 0. When φ=0, the second term equals 1, with no attenuation; when φ=0.5, the second term equals 0.667, and the adjustment amplitude decreases by 33%; when φ=1, the second term equals 0.5, and the adjustment amplitude decreases by 50%. This attenuation correction ensures that the adjustment amplitude is automatically suppressed under high-loss conditions, avoiding over-adjustment that could cause system oscillations.

[0055] Third item The cube root of the ratio of the energy storage threshold before and after the revision is used. This represents the deviation of the corrected energy storage threshold from the original threshold. When the corrected threshold is greater than the original threshold, the ratio is greater than 1, meaning the energy storage charging threshold has been raised, and the system has more capacity to absorb excess photovoltaic power. In this case, the balancing regulation should appropriately increase charging-related adjustment commands. When the corrected threshold is less than the original threshold, the ratio is less than 1, meaning the energy storage discharging threshold has been lowered, and the system can release more energy to support the load. In this case, the balancing regulation should appropriately increase discharging-related adjustment commands. The cube root operation is used to smooth out the impact of threshold changes on the correction coefficient. If the ratio itself is used directly, when S / S=2, this ratio will directly double η, which may lead to over-adjustment. The cube root approximates the cube root of 2 to 1.26, significantly compressing the amplification effect. Similarly, when S / S=0.5, the cube root is approximately 0.79, and the shrinkage effect is also compressed. The introduction of the cube root makes the change in the balancing correction coefficient smoother, improving the system stability.

[0056] Derived from closed-loop control tuning theory, the steady-state correction coefficient requires synchronous reference to three core variables: the proportion of power compensation, the magnitude of line loss, and the magnitude of energy storage threshold change. The power compensation proportion, reflected in the first term, indicates the degree of power imbalance under the current operating conditions. The magnitude of line loss, reflected in the second term, indicates the constraint of the system's own energy transmission efficiency on the adjustment action. The magnitude of the energy storage threshold change, reflected in the third term, indicates the guidance of the energy storage system's state change on the adjustment direction. After dimensionless normalization of all three variables, they are multiplied to obtain the final η. All operational terms in the formula are dimensionless, and the dimensions on both sides of the equals sign are perfectly matched. Taking the aforementioned implementation data as an example, ΔP = 38.723kW, P = 400kW, ΔP / P = 0.0968. φ = 0.12, φ+1 = 1.12, 1 / (φ+1) = 0.8929. S = 1.0, S = 0.9, S / S = 1.111, and the cube root is approximately 1.0357. Multiplying the three parts together, we get η = 0.0968 multiplied by 0.8929 multiplied by 1.0357, which equals 0.0895. This coefficient is approximately 0.09, indicating that the system's current deviation from the equilibrium state is small, requiring minor adjustments. Based on this coefficient, the controller issues the following commands: the photovoltaic array output power reference value is adjusted to 0.91 times the current value, the energy storage converter discharge rate is adjusted to 0.09 times the rated rate, and the bus parallel switch remains unchanged.

[0057] The control system employs four interconnected layers of data processing logic. These four layers are arranged in the order of loss measurement, energy storage setting, power calculation, and steady-state correction. The first layer is located within the multi-bus coupling loss sensing module. All input data consists of raw electrical parameters collected from the bus sites, and the sole output is the multi-bus dynamic coupling loss coefficient. The second layer is located within the energy storage tiered threshold correction module. Input data includes the loss coefficients from the first layer and the inherent energy storage parameters acquired by the energy storage parameter acquisition unit. Output is the charge and discharge threshold values ​​revised for each bus. The third layer is located within the dynamic power compensation calculation module. Input includes the output data from the first two layers plus photovoltaic and load power data collected by the source-load parameter acquisition unit. Output is the overall dynamic power compensation. The fourth layer is located within the steady-state deviation closed-loop suppression module, summarizing all output parameters from the first three layers to complete the final coefficient conversion. These four layers are sequentially connected, with each layer's calculation built upon the output results of the previous layer, and the data source for the calculation input is clearly defined. Hierarchical operation logic fixes the source of parameters for each step, ensuring data traceability consistency across the entire system.

[0058] The four-layer data processing logic has a fixed data flow direction. All output parameters from the previous layer are used as input parameters for the next layer. Each layer of processing logic independently corresponds to a processing unit within a module. These four layers are deployed within the multi-bus coupling loss sensing module, the energy storage stratification threshold correction module, the dynamic power compensation processing module, and the steady-state deviation closed-loop suppression module, respectively. All output data generated by each layer is completely transmitted to the next layer's processing unit; there is no skipping of layers to directly retrieve parameters or reverse data transmission. The first layer's output is only supplied to the second layer; the second layer's output, combined with existing acquired parameters, is supplied to the third layer; and the third layer's output, combined with all preceding parameters, is supplied to the fourth layer. Each of the four layers corresponds one-to-one with the processing units within the four main modules: the first layer is bound to the real-time processing logic unit within the multi-bus coupling loss sensing module; the second layer is bound to the stratification correction processing unit within the energy storage stratification threshold correction module; the third layer is bound to the multi-condition collaborative processing unit within the dynamic power compensation processing module; and the fourth layer is bound to the dedicated processing unit within the steady-state deviation closed-loop suppression module. The hardware carrier and processing logic are matched one-to-one; the processing logic cannot operate independently of its respective module. A fixed data flow constrains the parameter passing order, and the affiliation of each level of computational unit is clearly defined. This fixed flow, coupled with dedicated hardware, avoids computational errors caused by out-of-order parameter retrieval.

[0059] The multi-bus coupling loss sensing module, energy storage stratified threshold correction module, dynamic power compensation calculation module, and steady-state deviation closed-loop suppression module complete data interaction and logical operations according to a fixed timing sequence. The fixed timing sequence is as follows: parameter acquisition, loss calculation, threshold correction, power compensation, and closed-loop correction. The entire system executes these five fixed steps sequentially in a single operation cycle. First, the multi-bus coupling loss sensing module initiates the parameter acquisition process. The high-precision power acquisition chip captures four types of basic electrical data from the voltage and current acquisition terminals of each bus: branch operating current, branch equivalent impedance, inter-bus reference voltage difference, and bus rated operating power. After acquisition, the internal loss calculation is initiated. The real-time calculation logic unit, equipped with a normalized data processing program, performs normalized loss calculations based on the acquired electrical parameters to generate the multi-bus dynamic coupling loss coefficient. After the multi-bus dynamic coupling loss coefficient is transmitted, the energy storage stratified threshold correction module initiates energy storage parameter acquisition and threshold correction calculations. The energy storage parameter acquisition unit connects to the sampling port of the battery management system configured with energy storage on each bus, collecting three types of inherent parameters of the energy storage unit: initial rated charge threshold, remaining available capacity, and rated total capacity. The hierarchical correction calculation unit additionally receives the dynamic coupling loss coefficients of multiple buses and performs independent calculations for the loss coefficients corresponding to each bus, completing the correction of the charge / discharge thresholds of the energy storage units on each bus. After the threshold data is distributed, the dynamic power compensation calculation module initiates source-load acquisition and power compensation calculation. The source-load parameter acquisition unit collects the real-time photovoltaic output power and real-time load power consumption of the bus from the photovoltaic inverter output measurement point and the bus load input measurement point. The multi-condition collaborative calculation unit simultaneously receives the dynamic coupling loss coefficients of multiple buses and the corrected charge / discharge thresholds, splitting them into two independent calculation dimensions to calculate the compensation power required to compensate for circulating current losses and the compensation power that the energy storage can support, merging them to obtain the overall dynamic power compensation amount. After the compensation amount is generated, it is sent to the end module, where the steady-state deviation closed-loop suppression module performs steady-state coefficient calculations and closed-loop parameter adjustments. The steady-state deviation closed-loop suppression module summarizes all output results from the first three modules, calculates the steady-state equilibrium correction coefficient, and issues adjustment commands to the photovoltaic array controller, energy storage converter, and bus parallel switch based on the coefficient values. The next process only starts after all preceding processes are completed. While the previous module has not completed data output, the subsequent module remains in a data receiving and waiting state to prevent data corruption caused by simultaneous parallel operations of multiple modules. A fixed timing constraint module start / stop sequence ensures that subsequent operations only begin after the preceding data has been generated.

[0060] A control method for a multi-bus photovoltaic-storage microgrid is applied to the aforementioned multi-bus photovoltaic-storage microgrid control system. This method is executed by the microgrid controller. The microgrid controller uses time-sharing scheduling to sequentially complete the corresponding processes of its four main modules. The method includes the following steps.

[0061] Step S1: The microgrid controller, through the multi-bus coupling loss sensing module, collects the branch operating current, equivalent impedance, bus reference voltage difference, rated operating power, real-time operating duration, and sampling period parameters of each bus in the microgrid. Step S1 only performs the acquisition of the original electrical parameters of the entire system, and the acquisition time is the start of the first sampling period after the system starts. The branch operating current is measured by a current transformer, the equivalent impedance is calculated by injecting a small signal to measure the phase difference between voltage and current, the bus reference voltage difference is directly measured through the voltage sampling terminals of the parallel buses, the rated operating power is obtained from the parameters on the bus manufacturer's nameplate, the real-time operating duration is read from the controller's internal timer, and the sampling period duration is read from the preset value in the controller's memory.

[0062] Step S2: The microgrid controller, relying on the first-layer data processing logic, calculates the multi-bus dynamic coupling loss coefficient and transmits it to the energy storage tiered threshold correction module. The first-layer processing logic corresponds to the real-time processing logic unit within the multi-bus coupling loss sensing module. The input data is all the raw electrical parameters collected in step S1, and the output data is the multi-bus dynamic coupling loss coefficient. The calculation process follows... Execution. The multi-bus dynamic coupling loss coefficient is transmitted to the energy storage stratification threshold correction module through the communication link between modules.

[0063] Step S3: The microgrid controller collects the rated charge threshold, remaining capacity, rated capacity, real-time photovoltaic power, and load power parameters of the energy storage units through the energy storage tiered threshold correction module. Based on the second-layer data processing logic, it corrects the charge and discharge thresholds of each bus energy storage unit individually. The energy storage parameter acquisition unit connects to the sampling port of the battery management system configured with energy storage on each bus to collect the rated charge threshold, remaining capacity, and rated capacity of the energy storage units. The source-load parameter acquisition unit connects to the photovoltaic inverter output measurement point and the bus load input measurement point to collect real-time photovoltaic power and load power. The second-layer processing logic corresponds to the tiered correction processing unit within the energy storage tiered threshold correction module. The input data includes the multi-bus dynamic coupling loss coefficient output from the first layer and the collected energy storage parameters and source-load parameters. The output is the corrected charge and discharge thresholds for each bus. The processing follows... implement.

[0064] Step S4: The microgrid controller, through the dynamic power compensation calculation module and relying on the third-layer data calculation logic, combines the multi-bus dynamic coupling loss coefficient and the corrected energy storage charge threshold to calculate the system-wide dynamic power compensation. The third-layer calculation logic corresponds to the multi-condition collaborative calculation unit within the dynamic power compensation calculation module. Input data includes the multi-bus dynamic coupling loss coefficient output from the first layer, the corrected energy storage charge threshold output from the second layer, and the collected photovoltaic power and load power data. The output is the system-wide dynamic power compensation. The calculation process follows... implement.

[0065] Step S5: The microgrid controller, through the steady-state deviation closed-loop suppression module and relying on the fourth-layer data processing logic, calculates the steady-state equilibrium correction coefficient, and adjusts the microgrid operating parameters based on the steady-state equilibrium correction coefficient. The fourth-layer processing logic corresponds to a dedicated processing unit within the steady-state deviation closed-loop suppression module. The input data includes all output parameters from the first three layers, and the output is the steady-state equilibrium correction coefficient. The calculation process follows... Execution. The steady-state deviation closed-loop suppression module issues adjustment commands to the photovoltaic array controller, energy storage converter, and bus parallel switch according to the steady-state equilibrium correction coefficient, thereby changing the output of the photovoltaic array, the charging and discharging start-up and shutdown rate of the energy storage converter, and the switching status of the bus parallel switch.

[0066] Step S6: The microgrid controller repeats all steps S1 to S5 according to a fixed sampling period to complete the continuous parameter calculation and adjustment of the microgrid. The sampling period is selected with reference to the inherent energy storage charging and discharging response time of the energy storage converter, while also taking into account the parameter acquisition frequency of each acquisition chip. These two inherent hardware parameters serve as the reference benchmark for period setting. The period duration is not shorter than the shortest acquisition interval of the acquisition chip and not longer than the longest response interval of the energy storage converter. Each cycle is carried out in a fixed order of parameter acquisition, coefficient calculation, threshold correction, power compensation, and parameter adjustment. At the end of each cycle, three types of core operating parameters are refreshed synchronously: energy storage charging and discharging parameters, power compensation parameters, and steady-state equilibrium parameters. The new parameters are directly substituted into the calculation process of the next cycle. The method steps are bound to the system hardware and hierarchical calculation logic, forming a feasible periodic control process. Relying on the inherent hardware parameters to constrain the sampling period, the three types of core operating parameters are refreshed cyclically to adapt to the real-time changing operating conditions of the microgrid.

[0067] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments that can be applied to other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A multi-bus photovoltaic-storage microgrid control system, characterized in that, It includes a multi-bus coupling loss sensing module, an energy storage hierarchical threshold correction module, a dynamic power compensation calculation module, and a steady-state deviation closed-loop suppression module; the multi-bus coupling loss sensing module is used to collect the electrical operating parameters of each bus branch of the microgrid and calculate and output the multi-bus dynamic coupling loss coefficient. The energy storage stratification threshold correction module is communicatively connected to the multi-bus coupling loss sensing module. It is used to receive the multi-bus dynamic coupling loss coefficient and, in combination with the operating parameters of each bus energy storage unit, correct the charge and discharge threshold of each bus energy storage unit. The dynamic power compensation calculation module is communicatively connected to the energy storage hierarchical threshold correction module. It is used to receive the multi-bus dynamic coupling loss coefficient and the corrected charge and discharge threshold, and combine the microgrid source and load operating parameters to solve the global dynamic power compensation amount. The steady-state deviation closed-loop suppression module is communicatively connected to the dynamic power compensation calculation module. It is used to receive the multi-bus dynamic coupling loss coefficient, the corrected charge and discharge threshold, and the global dynamic power compensation amount, calculate the steady-state balance correction coefficient, and adjust the microgrid electrical operating parameters according to the steady-state balance correction coefficient.

2. The multi-bus photovoltaic-storage microgrid control system according to claim 1, characterized in that, The multi-bus coupling loss sensing module includes a high-precision power acquisition chip and a real-time computing logic unit. The high-precision power acquisition chip is used to acquire the operating current of the bus branches, the equivalent impedance of the branches, the reference voltage difference between the buses, and the rated operating power of the buses. The real-time computing logic unit is electrically connected to the high-precision power acquisition chip and is used to perform normalized loss calculation based on the electrical operating parameters acquired by the high-precision power acquisition chip, and output the multi-bus dynamic coupling loss coefficient.

3. The multi-bus photovoltaic-storage microgrid control system according to claim 1, characterized in that, The energy storage stratified threshold correction module includes an energy storage parameter acquisition unit and a stratified correction calculation unit. The energy storage parameter acquisition unit is used to acquire the initial rated charge threshold, remaining available capacity, and rated total capacity of each bus energy storage unit. The stratified correction calculation unit is electrically connected to the energy storage parameter acquisition unit and the multi-bus coupling loss sensing module, and is used to independently complete the correction calculation of the charge threshold of a single bus energy storage unit based on the loss parameters of different buses.

4. The multi-bus photovoltaic-storage microgrid control system according to claim 1, characterized in that, The dynamic power compensation calculation module includes a source-load parameter acquisition unit and a multi-condition collaborative calculation unit. The source-load parameter acquisition unit is used to acquire the real-time photovoltaic output power of the bus and the real-time load power consumption of the bus. The multi-condition collaborative calculation unit is electrically connected to the source-load parameter acquisition unit and the energy storage hierarchical threshold correction module, and is used to superimpose the branch coupling loss compensation dimension and the energy storage threshold deviation compensation dimension to calculate the global dynamic power compensation amount.

5. The multi-bus photovoltaic-storage microgrid control system according to claim 1, characterized in that, The control system is internally configured with four layers of sequentially connected data processing logic. The first layer of processing logic generates the multi-bus dynamic coupling loss coefficient based on the electrical parameters collected by the bus. The second layer of processing logic generates the corrected charge and discharge charge threshold based on the multi-bus dynamic coupling loss coefficient and the inherent parameters of energy storage. The third layer of processing logic generates the global dynamic power compensation amount based on the multi-bus dynamic coupling loss coefficient, the corrected charge and discharge charge threshold, and the source and load parameters. The fourth layer of processing logic generates the steady-state equilibrium correction coefficient based on the output parameters of the first three types of processing.

6. The multi-bus photovoltaic-storage microgrid control system according to claim 5, characterized in that, The four layers of data operation logic have a fixed data flow direction. All output parameters obtained from the previous layer are used as input parameters for the next layer of operation logic. Each layer of operation logic independently corresponds to an internal operation unit of a module. The four layers of operation logic are respectively deployed inside the multi-bus coupling loss sensing module, the energy storage stratification threshold correction module, the dynamic power compensation operation module, and the steady-state deviation closed-loop suppression module.

7. The multi-bus photovoltaic-storage microgrid control system according to claim 1, characterized in that, The steady-state deviation closed-loop suppression module regulates the output power of the photovoltaic array, the charging and discharging rate of the energy storage unit, and the operating status of the multi-bus parallel circulating current. Based on the steady-state balance correction coefficient, the steady-state deviation closed-loop suppression module completes the balance regulation of the microgrid power, voltage, and frequency.

8. The multi-bus photovoltaic-storage microgrid control system according to claim 1, characterized in that, The multi-bus coupling loss sensing module, the energy storage stratification threshold correction module, the dynamic power compensation calculation module, and the steady-state deviation closed-loop suppression module complete data interaction and logical operations according to a fixed timing sequence, which is parameter acquisition, loss calculation, threshold correction, power compensation, and closed-loop correction in sequence.

9. A control method for a multi-bus photovoltaic-storage microgrid, applied to the multi-bus photovoltaic-storage microgrid control system according to any one of claims 1 to 8, characterized in that, The method is executed by a microgrid controller and includes the following steps: S1. The microgrid controller collects the branch operating current, equivalent impedance, bus reference voltage difference, rated operating power, real-time operating time and sampling period parameters of each bus of the microgrid through the multi-bus coupling loss sensing module. S2. The microgrid controller calculates the multi-bus dynamic coupling loss coefficient based on the first-layer data operation logic, and transmits the multi-bus dynamic coupling loss coefficient to the energy storage layer threshold correction module. S3. The microgrid controller collects the rated charge threshold, remaining capacity, rated capacity, real-time photovoltaic power and load power parameters of the energy storage unit through the energy storage hierarchical threshold correction module. Based on the second-layer data operation logic, it corrects the charge and discharge threshold of each bus energy storage unit one by one. S4. The microgrid controller calculates the system-wide dynamic power compensation amount by relying on the third-layer data operation logic through the dynamic power compensation calculation module, combined with the multi-bus dynamic coupling loss coefficient and the corrected energy storage charge threshold. S5. The microgrid controller calculates the steady-state equilibrium correction coefficient through the steady-state deviation closed-loop suppression module based on the fourth-layer data operation logic, and adjusts the microgrid operating parameters based on the steady-state equilibrium correction coefficient. S6. The microgrid controller repeats all steps from S1 to S5 according to a fixed sampling period to complete the continuous parameter calculation and parameter adjustment of the microgrid.

10. The multi-bus photovoltaic-storage microgrid control method according to claim 9, characterized in that, The method completes cyclic calculations based on a fixed sampling period, which matches the energy storage charging and discharging response time and the system parameter acquisition frequency. The method sequentially completes a fixed process of parameter acquisition, coefficient calculation, threshold correction, power compensation, and parameter adjustment, continuously updating the microgrid energy storage charging and discharging parameters, power compensation parameters, and steady-state equilibrium parameters.

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