Power supply control system of photovoltaic energy storage charging pile

Abstract

The invention relates to the technical field of power supply control, in particular to a power supply control system of a photovoltaic energy storage charging pile, which comprises a load power analysis module, an energy storage battery pack management module, a charging and discharging dynamic regulation and control module, an abnormal charging and discharging correction module and a power distribution optimization module. According to the invention, power demand analysis and battery management optimization are carried out. By dynamically analyzing the instantaneous power and fluctuation of the photovoltaic energy storage charging pile, the stability of the load can be more accurately judged, adjustment is carried out according to different fluctuation levels, finer energy allocation is achieved, and by monitoring and adjusting the internal resistance of the battery in real time, abnormal charging and discharging behaviors can be found and corrected in time. According to the invention, safe operation and reliability of energy output are ensured, the utilization rate of photovoltaic power generation can be improved through optimized power distribution, the power supply proportion of the power grid and photovoltaic power generation is dynamically adjusted according to the actual power supply condition, energy waste is effectively reduced, and the economical efficiency and environmental protection property of overall electric energy are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply control, and in particular to a power supply control system for a photovoltaic energy storage charging pile. Background Art

[0002] The field of power supply control technology involves the dispatching, distribution, conversion and management of electric energy to ensure the stable operation of the power system in different application scenarios. This technology covers core contents such as power management, power quality optimization, energy storage system control, load balancing, grid interactive regulation, etc., and is widely used in distributed power management, smart grid, electric vehicle charging infrastructure, microgrid power supply and other fields. The power supply control system usually includes power conversion equipment, power conditioning devices, energy storage units, grid connection interfaces and control strategies, aiming to optimize power utilization efficiency, improve power supply reliability, reduce energy loss, and support intelligent switching of multiple power modes.

[0003] The power supply control system of photovoltaic energy storage charging piles is used to manage the flow of electric energy between photovoltaic power generation, energy storage devices and electric vehicle charging piles to optimize energy utilization efficiency, improve the system's independent power supply capacity, and reduce dependence on the power grid. Through intelligent scheduling and control, the system realizes functions such as photovoltaic power generation priority power supply, energy storage battery charging and discharging optimization management, and grid auxiliary compensation to ensure that the charging piles operate stably under different lighting conditions and load conditions. The system is suitable for scenarios such as public charging stations, residential and commercial complexes. It can reduce carbon emissions while improving the utilization rate of new energy and enhancing the economy and reliability of charging facilities.

[0004] Traditional control systems mostly use fixed threshold settings or time-based power adjustment modes, which cannot quickly respond to instantaneous fluctuations in the load of charging piles, resulting in lag in charge and discharge control. Traditional systems only manage the charge and discharge of battery packs based on preset thresholds, which cannot fully match the actual power demand. Energy storage battery packs will still discharge at high power when the load is low, or fail to release energy storage in time when the load is high, resulting in energy waste or insufficient energy supply. Traditional systems usually rely on statistical analysis of long-term operating data to correct abnormal charge and discharge, and cannot accurately identify abnormal conditions at the beginning, resulting in battery cells being in a high-loss state for a long time, accelerating the decline of the energy storage system. In terms of power distribution, traditional systems are regulated according to a single power supply mode, ignoring the coordinated energy supply relationship between photovoltaics, energy storage and the power grid, making it difficult to optimize energy distribution under dynamic load conditions, resulting in insufficient adaptability of the power supply system under different load scenarios. Summary of the invention

[0005] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a power supply control system for a photovoltaic energy storage charging pile.

[0006] In order to achieve the above object, the present invention adopts the following technical solution: a power supply control system for a photovoltaic energy storage charging pile, the system comprising: The load power analysis module obtains the load power demand of the photovoltaic energy storage charging pile, calculates the load fluctuation amplitude according to the load power change per unit time, determines the load power fluctuation level according to the power change rate, and establishes the load power fluctuation classification information; The energy storage battery pack management module calculates the available capacity of the battery unit based on the load power fluctuation division information, identifies the rechargeable battery unit and the dischargeable battery unit, selects the energy storage battery unit that meets the charging and discharging conditions in combination with the health status of the battery unit, and generates a list of rechargeable and dischargeable battery units; The charge and discharge dynamic control module calls the list of chargeable and dischargeable battery cells and the load power fluctuation division information, detects the internal resistance of the battery cells, calculates the charge and discharge priority of the cells, adjusts the charge and discharge sequence, optimizes the charge and discharge power output, and generates the charge and discharge power matching information of the energy storage unit; The abnormal charge and discharge correction module calls the charge and discharge power matching information of the energy storage unit, obtains the dynamic change data of the internal resistance of the battery pack, calculates the internal resistance change rate, sets the abnormal internal resistance fluctuation threshold, determines whether there is abnormal charge and discharge behavior, adjusts the charge and discharge power output, and generates abnormal charge and discharge correction information.

[0007] The present invention has improvements in that the load power fluctuation classification information includes load fluctuation rate, load change amplitude, power demand change trend and charging pile load classification; the list of rechargeable battery cells includes rechargeable battery cell numbers, rechargeable battery cell numbers, battery cell available capacity and battery cell health status; the energy storage unit charge and discharge power matching information specifically includes unit output power, unit input power, unit charge and discharge priority and battery balanced charge and discharge parameters; the abnormal charge and discharge correction information includes abnormal internal resistance change, abnormal charge and discharge adjustment amplitude, corrected power compensation coefficient and battery internal resistance stability judgment value.

[0008] The present invention is improved in that the load power analysis module comprises: The instantaneous power monitoring submodule obtains the load power demand of the photovoltaic energy storage charging pile, collects the output current of the charging gun, obtains the voltage value of the DC bus, and calculates the instantaneous power value; The load fluctuation calculation submodule calls the instantaneous power value, calculates the change in load power per unit time, and determines the load fluctuation amplitude based on the change, and uses the formula: ; Calculate and obtain the load power fluctuation value; in, Represents the load power fluctuation value, Representative The instantaneous power at the moment, represents the number of time slices during the computation period, Represents the instantaneous power change between adjacent time slices, Representative The timestamp of the moment, is the time decay factor, is the base of natural logarithms; The power demand state screening submodule calls the load power fluctuation value, divides the charging pile power demand state into multiple levels according to a preset fluctuation level classification standard, and establishes load power fluctuation classification information.

[0009] The present invention is improved in that the energy storage battery pack management module comprises: The power state acquisition submodule acquires the remaining power percentage of the energy storage battery group based on the load power fluctuation division information, and calculates and acquires the available capacity of the battery unit; The battery cell screening submodule calls the available capacity of the battery cell, identifies the chargeable battery cell and the dischargeable battery cell according to the remaining power percentage threshold, and uses the formula based on the health status of the battery cell: ; Calculate and obtain the charging and discharging adaptability index of the battery unit; in, Represents the battery cell charge and discharge adaptability index, Represents the available capacity of the battery cell, Represents the minimum available capacity threshold. Represents the maximum available capacity. Represents the health status of the battery cell, is the health status attenuation factor, represents the base of natural logarithms; The chargeable and dischargeable unit generation submodule calls the battery unit charge and discharge adaptability index, screens energy storage battery units that meet the charge and discharge conditions according to a preset adaptability threshold, and establishes a list of chargeable and dischargeable battery units.

[0010] The present invention is improved in that the charging and discharging dynamic control module comprises: The battery cell status detection submodule calls the list of chargeable and dischargeable battery cells and the load power fluctuation division information, detects the internal resistance of the battery cell, and obtains the impedance information of the battery cell; The charge and discharge priority calculation submodule calls the impedance information of the battery cell, combines the remaining power of the battery cell, and uses the formula: ; Calculate and obtain the charge and discharge priority value; in, Represents the charge and discharge priority value, Represents the remaining power of the battery cell, Represents the minimum power threshold, represents the internal resistance of the battery cell, Represents the power balance reference value set by the energy storage system. Represents the power balancing factor, is the base of natural logarithms; The power matching adjustment submodule calls the charging and discharging priority value and the load power fluctuation division information, adjusts the charging and discharging sequence, adjusts the charging and discharging power output in combination with the discharge demand of the charging pile and the load power fluctuation, and establishes the charging and discharging power matching information of the energy storage unit.

[0011] The present invention is improved in that the abnormal charge and discharge correction module comprises: The internal resistance change detection submodule calls the charging and discharging power matching information of the energy storage unit, obtains the dynamic change data of the internal resistance of the battery pack, extracts the internal resistance change amount per unit time, and calculates and obtains the internal resistance change rate of the battery pack; The abnormal charge and discharge judgment submodule calls the battery pack internal resistance change rate, sets the abnormal internal resistance fluctuation threshold, judges whether there is abnormal charge and discharge behavior, and uses the formula: ; Calculate and obtain abnormal charge and discharge trend values; in, Represents the abnormal charge and discharge trend value, Represents the internal resistance of the battery pack at the current moment, Represents the internal resistance of the battery pack at the previous moment, represents the time interval, Represents the remaining battery power ratio. is the power impact factor, represents the base of natural logarithms; The charge and discharge power adjustment submodule calls the abnormal charge and discharge trend value, compares it with the abnormal trend standard, adjusts the charge and discharge power output, and establishes abnormal charge and discharge correction information.

[0012] The present invention is improved in that the system further comprises a power distribution optimization module; The power allocation optimization module calls the abnormal charge and discharge correction information, obtains the photovoltaic power generation power and the power supply capacity of the power grid, calculates the instantaneous power compensation demand, adjusts the power supply ratio of the photovoltaic energy storage system, and generates optimized power allocation parameters; The optimized power allocation parameters specifically refer to the photovoltaic power supply ratio, grid compensation power, energy storage system allocation power and power regulation response time.

[0013] The present invention is improved in that the power allocation optimization module comprises: The power supply capacity acquisition submodule calls the abnormal charge and discharge correction information, obtains the photovoltaic power generation power and the power supply capacity of the power grid, and calculates and obtains the total photovoltaic and power grid power supply; The instantaneous power compensation calculation submodule calls the total amount of photovoltaic and grid power supply, using the formula: ; Calculate and obtain the instantaneous power compensation demand; in, Represents the instantaneous power compensation demand, Represents the current load power demand, Represents photovoltaic power generation power, Represents the grid power supply, represents the current discharge rate of the energy storage system, is the discharge ratio weight factor; The power allocation adjustment submodule calls the instantaneous power compensation demand, adjusts the power supply ratio of the photovoltaic energy storage system, and establishes optimized power allocation parameters.

[0014] Compared with the prior art, the advantages and positive effects of the present invention are: In the present invention, more efficient energy utilization is achieved through power demand analysis and battery management optimization. By dynamically analyzing the instantaneous power and fluctuation of the photovoltaic energy storage charging pile, the stability of the load can be more accurately judged and adjusted for different fluctuation levels, and more refined energy allocation can be achieved, so that the energy storage battery pack can more effectively respond to power changes during the charging and discharging process, maintain the health of the battery and extend its service life. Through real-time monitoring and adjustment of the battery internal resistance, abnormal charging and discharging behaviors can be discovered and corrected in time, ensuring the safe operation of the system and the reliability of energy output. Through optimized power distribution, the utilization rate of photovoltaic power generation can be improved, and the power supply ratio of the power grid and photovoltaic power generation can be dynamically adjusted according to the actual power supply situation, effectively reducing energy waste and improving the economy and environmental protection of the overall electric energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a system flow chart of the present invention; Figure 2 It is a flow chart of the load power analysis module of the present invention; Figure 3 This is a flow chart of the energy storage battery management module of the present invention; Figure 4 This is a flow chart of the charge and discharge dynamic control module of the present invention; Figure 5 This is a flow chart of the abnormal charge and discharge correction module of the present invention; Figure 6 This is a flow chart of the power allocation optimization module of the present invention. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0017] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating positions or positional relationships, are based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, in the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0018] See also Figure 1 The present invention provides a technical solution: a power supply control system for a photovoltaic energy storage charging pile, the system comprising: The load power analysis module obtains the load power demand of the photovoltaic energy storage charging pile, collects the output current of the charging gun and the DC bus voltage, and calculates the instantaneous power. It calculates the load fluctuation amplitude according to the load power change per unit time, sets the charging pile load fluctuation rate threshold, determines the load power fluctuation level according to the power change rate, screens the charging pile power demand states of multiple fluctuation levels, and establishes load power fluctuation classification information; The energy storage battery group management module obtains the remaining power percentage of the energy storage battery group based on the load power fluctuation classification information, calculates the available capacity of the battery unit, identifies the rechargeable battery units and the dischargeable battery units according to the remaining power percentage threshold, and selects the energy storage battery units that meet the charging and discharging conditions in combination with the health status of the battery units, and generates a list of rechargeable and dischargeable battery units; The dynamic charge and discharge control module calls the list of chargeable and dischargeable battery cells and the load power fluctuation division information, detects the internal resistance of the battery cells, calculates the charge and discharge priority of the cells, adjusts the charge and discharge sequence, optimizes the charge and discharge power output, and generates the charge and discharge power matching information of the energy storage unit; The abnormal charge and discharge correction module calls the charge and discharge power matching information of the energy storage unit, obtains the dynamic change data of the internal resistance of the battery pack, calculates the internal resistance change rate, sets the abnormal internal resistance fluctuation threshold, determines whether there is abnormal charge and discharge behavior, adjusts the charge and discharge power output, and generates abnormal charge and discharge correction information; The power allocation optimization module calls abnormal charging and discharging correction information, obtains photovoltaic power generation power and grid power supply capacity, calculates instantaneous power compensation demand, adjusts the power supply ratio of the photovoltaic energy storage system, and generates optimized power allocation parameters.

[0019] The load power fluctuation classification information includes the load fluctuation rate, load change amplitude, power demand change trend and charging pile load classification. The list of rechargeable battery units includes the rechargeable battery unit number, the dischargeable battery unit number, the battery unit available capacity and the battery unit health status. The energy storage unit charging and discharging power matching information includes the unit output power, unit input power, unit charging and discharging priority and battery balanced charging and discharging parameters. The abnormal charging and discharging correction information includes the abnormal internal resistance change, the abnormal charging and discharging adjustment amplitude, the corrected power compensation coefficient and the battery internal resistance stability judgment value. The optimized power allocation parameters specifically refer to the photovoltaic power supply ratio, the grid compensation power, the energy storage system allocated power and the power regulation response time.

[0020] See also Figure 2 , the load power analysis module includes: The instantaneous power monitoring submodule obtains the load power demand of the photovoltaic energy storage charging pile, collects the output current of the charging gun, obtains the voltage value of the DC bus, and calculates the instantaneous power value; The instantaneous power monitoring submodule performs the task of obtaining the load power demand of the photovoltaic energy storage charging pile, calling the power management system of the photovoltaic energy storage charging pile, and obtaining the remaining power of the current energy storage battery. and maximum charge and discharge power , and then call the charging pile controller to obtain the current usage status of the charging gun, including whether it is in charging mode, connection status and charging stage, combined with the maximum output power of the charging gun and charged capacity Calculate the current load power demand; in the process of collecting the output current of the charging gun, use a current transformer or Hall sensor to collect the output current , and every second The sampling frequency is stored in the data buffer area, and the real-time voltage value of the DC bus is obtained at the same time. , read the voltage data through high-precision voltage sensor or directly from the DC bus control module, all collected data will be synchronized to the central processing unit for calculation. After the data is synchronized, the formula Calculate instantaneous power value ; For example, at a certain moment, if the DC bus voltage The monitoring value is 720V, the output current of the charging gun The monitoring value is 50A, then the instantaneous power , and finally stored in the charging pile power demand database for subsequent analysis. In this calculation process, the sampling frequency As a key factor affecting data accuracy, its rationality must be ensured. The setting basis is based on the dynamic characteristics of the charging process. Generally, it is selected between 1Hz (i.e., 1 sampling per second) and 10Hz (i.e., 10 sampling per second). If the load change is too low, it will not be able to accurately capture the load change. If it is too high, it may cause data redundancy and increase the amount of calculation. In this embodiment, To ensure a balance between calculation accuracy and calculation efficiency, this value is derived from the instantaneous power change rate of the charging device, which usually does not fluctuate by more than 5% within 200ms. Therefore, sampling every 200ms can meet the accuracy requirements.

[0021] The load fluctuation calculation submodule calls the instantaneous power value, calculates the change in load power per unit time, and determines the load fluctuation amplitude based on the change, using the formula: ; Calculate and obtain the load power fluctuation value; in, Represents the load power fluctuation value, Representative The instantaneous power at the moment, represents the number of time slices during the computation period, Represents the instantaneous power change between adjacent time slices, Representative The timestamp of the moment, is the time decay factor, is the base of natural logarithms; The load fluctuation calculation submodule calls the stored historical power data based on the calculated instantaneous power value and extracts the power sequence within the unit time interval. First, the power change of adjacent time slices is calculated for the sequence to obtain the power change between each time slice , then combined with the timestamp information Calculate the time decay factor , used to adjust the contribution of different time slices to the total power fluctuation, using the formula ; Calculate the load power fluctuation value per unit time ; In the specific implementation, set the sampling interval is 1s, , if the instantaneous power data of the 5 time slices are , the calculation process is as follows: ; The load power fluctuation value is calculated from this , which will be used for subsequent classification calculation of power demand status. is the time attenuation factor, which is set based on the importance of load fluctuations to system response. This value directly affects the degree of influence of data far from the current moment on the fluctuation calculation. If the setting is too high, the influence of historical data will decay rapidly, causing fluctuations in a short period of time to be over-magnified. If the setting is too low, the impact of long-term data on fluctuations will be too large, which is not conducive to real-time performance. In this embodiment, The basis is the typical fluctuation range of the charging pile load within 20 seconds, and the value range is generally Between, the lower Suitable for steady loads, higher Applicable to fast changing loads, this embodiment is selected in combination with actual application To balance the impact of long-term and short-term data.

[0022] The power demand state screening submodule calls the load power fluctuation value, divides the charging pile power demand state into multiple levels according to the preset fluctuation level classification standard, and establishes the load power fluctuation classification information.

[0023] The power demand state screening submodule is based on the calculated load power fluctuation value ,The charging pile power demand state classification is performed .First, the preset fluctuation level classification standard is called to divide the power demand state into multiple levels based on the power fluctuation value. The classification standard is shown in Table 1.

[0024] Table 1 Classification standard of load power fluctuation ; Table 1 lists the load power fluctuation classification standard, which is used to classify the power demand state. As shown in Table 1, assume that the previous calculation step obtains kW, then according to the standards in Table 1, its load power fluctuation is between Level 1 and Level 3, satisfying , so the power demand state is judged as "slight fluctuation"; in the specific screening execution process, the system first calls the fluctuation classification rule, and compares the intervals Determine the state level, and then store it in the charging pile power demand database, and update the current load state information for scheduling control decisions and load optimization management. Among them, the fluctuation level classification standard is used as a benchmark value, and its setting basis is the impact of charging pile power fluctuations on the power grid and energy storage system. The data comes from the typical load variation range of the charging pile. The steady-state load usually fluctuates less than 1kW, slight fluctuations occur between 1 and 3kW, medium fluctuations are between 3 and 5kW, and violent fluctuations exceed 5kW. The above classification is based on the load variation law under different charging strategies.

[0025] See also Figure 3 , the energy storage battery pack management module includes: The power state acquisition submodule obtains the remaining power percentage of the energy storage battery pack based on the load power fluctuation classification information, and calculates and obtains the available capacity of the battery unit; The power state acquisition submodule is based on the load power fluctuation division information. First, it calls the total power data of the current battery pack from the energy storage management system. and the total capacity of the energy storage system , calculate the remaining power percentage ; Then, call the data interface of each battery cell separately to extract the current power of all battery cells ,total battery cells and store them in the data list And calculate the available capacity of each battery cell , which is limited by the maximum available capacity of the battery cell and minimum available capacity Limit, calculated as ,when When the unit is considered unavailable, the maximum available capacity The rated capacity of the battery cell is set according to the factory rated value, such as the typical Set to 50kWh, the minimum available capacity Depends on the safe discharge threshold. To avoid over-discharge affecting battery life, this value is set to 20% of the rated capacity, that is, , at a certain moment, if the total capacity of the energy storage battery kWh, current storage capacity kWh, we can calculate , for a single battery cell, assume kWh, kWh, if a unit currently stores electricity kWh, then kWh, this calculation method is applicable to all battery cells, and ultimately the available capacity of each battery cell is obtained.

[0026] The battery cell screening submodule calls the available capacity of the battery cell, identifies the rechargeable battery cells and the dischargeable battery cells according to the remaining power percentage threshold, and uses the formula based on the health status of the battery cell: ; Calculate and obtain the charging and discharging adaptability index of the battery unit; in, Represents the battery cell charge and discharge adaptability index, Represents the available capacity of the battery cell, Represents the minimum available capacity threshold. Represents the maximum available capacity. Represents the health status of the battery cell, is the health status attenuation factor, represents the base of natural logarithms; The battery cell screening submodule calls the calculated available capacity of the battery cells and first divides the battery cells into rechargeable battery cells and dischargeable battery cells according to the set remaining power percentage threshold. and The setting is based on the charge and discharge strategy, usually referring to the safety range recommended by the battery manufacturer to avoid deep charge and discharge that may cause battery life degradation. As the charging threshold, that is, when The battery unit enters charging mode, and As the discharge threshold, that is, when The battery cell can be discharged when the remaining power percentage of the battery cell When , the cell is classified as a releasable cell. After classification, the health status of each battery cell is further extracted. , which indicates the current life attenuation of the battery cell. The value range is usually 0 to 1. The larger the value, the worse the health condition. On this basis, the calculation obtains the charge and discharge adaptability index of the battery cell. , calculated as: ; Among them, the health status attenuation factor Set according to the battery life curve, usually changes with the increase of battery cycle times, the value range is , lithium iron phosphate battery conventionally takes To reflect its lower capacity decay rate, a battery cell is selected. kWh, kWh, kWh, health status , the calculation process is as follows: ; Calculate the charge and discharge adaptability index of the battery cell , which is used for subsequent filtering operations.

[0027] The chargeable and dischargeable unit generation submodule calls the battery unit charge and discharge adaptability index, selects the energy storage battery units that meet the charge and discharge conditions according to the preset adaptability threshold, and establishes a list of chargeable and dischargeable battery units; The chargeable and dischargeable cell generation submodule calls the calculated battery cell charge and discharge adaptability index First, the preset adaptability threshold is used for screening. The adaptability threshold is set according to the performance decay curve of the battery cell, which is generally As a charge and discharge condition, battery cells with a value lower than this are not recommended to participate in charging and discharging due to poor health or low available capacity. The screening process first traverses the data records of all battery cells. , compare each unit in turn Whether the value meets the screening conditions, if so, the battery unit number is stored in the list ; There are 5 battery cells, and their charge and discharge adaptability indexes are shown in Table 2 below.

[0028] Table 2 Battery cell charge and discharge adaptability index table ; As shown in Table 2, among the five battery cells, the adaptability indexes of No. 1, 3, and 4 are All are greater than 0.5, so they are screened as chargeable and dischargeable units and finally stored in the list .

[0029] See also Figure 4 , the charging and discharging dynamic control module includes: The battery cell status detection submodule calls the list of chargeable and dischargeable battery cells and the load power fluctuation division information to detect the internal resistance of the battery cell and obtain the impedance information of the battery cell; The battery cell status detection submodule calls the list of rechargeable battery cells and load power fluctuation division information, reads the numbers of all battery cells in the list from the energy storage management system, and calls the impedance detection interface of each cell to obtain the battery internal resistance The impedance information can be obtained through AC impedance measurement or pulse current testing. The equivalent circuit model is usually used to estimate the internal impedance. When collecting impedance information, the system applies a short-term pulse current to each battery cell. , measure the voltage change , and calculate the internal resistance ; Assume that a pulse current is applied to a battery cell , the measured voltage change , then the internal resistance is calculated The impedance information of all battery cells is stored in the database, and under the influence of the load power fluctuation division information, the impedance data is updated according to the historical load characteristics of each battery cell to obtain complete battery cell impedance information and internal resistance value. As an important indicator of battery health, it is usually between 0.001Ω and 0.01Ω. The baseline value is set to ,when When it exceeds 0.005Ω, the system marks that the internal resistance of the battery cell is too high, and priority should be given to reducing load distribution to prevent overheating or increased battery aging. The basis for setting this benchmark value is based on the safe range of the maximum acceptable discharge current of the battery cell to ensure that the battery cell remains in a stable working range under load changes.

[0030] The charge and discharge priority calculation submodule calls the impedance information of the battery cell, combines the remaining power of the battery cell, and uses the formula: ; Calculate and obtain the charge and discharge priority value; in, Represents the charge and discharge priority value, Represents the remaining power of the battery cell, Represents the minimum power threshold, represents the internal resistance of the battery cell, Represents the power balance reference value set by the energy storage system. Represents the power balancing factor, is the base of natural logarithms; The charge and discharge priority calculation submodule calls the impedance information of the battery cell and combines it with the remaining power to first read the remaining power of all battery cells from the database. and minimum power threshold , and based on the battery impedance information Calculate the charge and discharge priority value , calculated as: ; Among them, the power balance reference value Used to measure the current battery power relative to the overall balance of the energy storage system, power balance influencing factor Control the balance adjustment range, set , select a battery cell, if its remaining power kWh, minimum power threshold kWh, impedance , energy storage system charge balance reference value kWh, the calculation process is as follows: ; Calculate the charge and discharge priority value of the battery cell This value is used for subsequent power matching adjustment, where the power balance reference value It is set to 35 kWh. This value is derived from the total power distribution of the current energy storage system. It is determined by counting the average remaining power of all battery cells so that the power is evenly distributed among all cells. The power balance influencing factor Set to 0.02, this value is adjusted based on the historical charge and discharge data of the battery cell to ensure that the balancing adjustment is not overly sensitive, so as to avoid frequent switching of charge and discharge, which in turn affects the battery life.

[0031] The power matching adjustment submodule calls the charge and discharge priority value and the load power fluctuation division information to adjust the charge and discharge sequence, adjusts the charge and discharge power output in combination with the discharge demand of the charging pile and the load power fluctuation, and establishes the charge and discharge power matching information of the energy storage unit.

[0032] The power matching adjustment submodule calls the calculated charge and discharge priority values ​​and load power fluctuation division information. First, the battery cell list is sorted according to the charge and discharge priority values, with the cells with larger priority values ​​sorted first, and the discharge demand data of the charging pile is called. and load power fluctuation data , adjust the charging and discharging order of the energy storage battery unit according to the current load conditions, calculate the charging and discharging power output, and establish the charging and discharging power matching information of the energy storage unit; in the specific execution process, the system first reads the priority values ​​of all battery units, and arranges them in descending order, selects the battery unit with the highest priority and allocates the charging and discharging power in turn, ensuring that the total output power after allocation meets This constraint, in the calculation process, assumes that the current discharge demand of the charging pile is kW, load power fluctuation kW, if the energy storage unit priority value and its maximum discharge power are shown in Table 3: Table 3 Battery unit charge and discharge priority and maximum discharge power table ; As shown in Table 3, when the current demand is 50 kW, the system first allocates the highest priority battery unit 1, providing its maximum discharge power of 20 kW, then allocates battery unit 2, providing 15 kW, then allocates battery unit 3, providing 12 kW, and finally allocates battery unit 4, providing 3 kW, so that the final matching total power reaches 50 kW, completing the establishment of the energy storage unit charging and discharging power matching information, where the maximum discharge power According to the discharge rate of the battery cell Calculate and set the value based on the battery type and manufacturer's calibration value to ensure operation within a reasonable current density range and load power fluctuation threshold Set to 2 kW, when When it exceeds 2 kW, the system adjusts the charging and discharging priority strategy to avoid abnormal power scheduling due to excessive load fluctuations. The threshold is set based on the 95th percentile value of historical load fluctuation data to ensure that the system can operate stably under most load conditions.

[0033] See also Figure 5 , the abnormal charge and discharge correction module includes: The internal resistance change detection submodule calls the energy storage unit charging and discharging power matching information, obtains the dynamic change data of the battery pack internal resistance, extracts the internal resistance change amount per unit time, and calculates the change rate of the battery pack internal resistance; The internal resistance change detection submodule calls the energy storage unit charging and discharging power matching information, first reading the current working status data of all energy storage units, including the charging and discharging power and charge and discharge time , call the battery management system (BMS) to monitor the internal resistance of the battery cell in real time The data acquisition method can be DC discharge method or AC impedance measurement method. The specific steps are to apply a known current , measure the voltage change , calculate the current internal resistance ; In a unit of time, the system records the internal resistance data at multiple time points , and calculate the change of internal resistance at adjacent time points ; For example, within a certain period of time, set the sampling time interval s, the internal resistance values ​​at five consecutive moments are , then the changes in internal resistance at adjacent moments are calculated as follows: ; ; ; ; Then, the rate of change of internal resistance per unit time is calculated using the formula ,get ; ; ; ; Get battery pack internal resistance change rate data , where the time interval The basis for setting s is that the sampling interval of conventional energy storage battery management systems is usually set between 1s and 10s, and 5s is selected as a reasonable setting to balance the dynamic response of charge and discharge and data accuracy. If the sampling time interval is too short, the sampling data may be too greatly affected by transient changes. If it is too long, it may not be able to reflect the subtle fluctuation trend of battery impedance in time.

[0034] The abnormal charge and discharge judgment submodule calls the battery pack internal resistance change rate, sets the abnormal internal resistance fluctuation threshold, judges whether there is abnormal charge and discharge behavior, and uses the formula: ; Calculate and obtain abnormal charge and discharge trend values; in, Represents the abnormal charge and discharge trend value, Represents the internal resistance of the battery pack at the current moment, Represents the internal resistance of the battery pack at the previous moment, represents the time interval, Represents the remaining battery power ratio. is the power impact factor, represents the base of natural logarithms; The abnormal charge and discharge judgment submodule calls the battery pack internal resistance change rate data and first sets the abnormal internal resistance fluctuation threshold The threshold is defined as the allowable range of the battery internal resistance change rate under normal conditions. If the internal resistance change rate exceeds the threshold, it is determined that there is abnormal charging and discharging behavior, and the abnormal charging and discharging trend value is calculated. , calculated as: ; Among them, the remaining power ratio The current remaining battery power Maximum battery capacity The ratio of power consumption is set to Control the effect of remaining power on abnormal trends, set , select the parameter value measured at a certain moment , , time interval s, the current remaining battery power kWh, maximum battery capacity kWh, then calculate the remaining power ratio If you set , the calculation process is as follows: ; Calculate the abnormal charge and discharge trend value , which is greater than the threshold , it is judged that the battery cell may have abnormal charging and discharging behavior, among which the abnormal internal resistance fluctuation threshold The basis for setting is that under normal charging and discharging conditions, the internal resistance change rate of the battery is generally maintained at Within the range, if it exceeds This indicates that the battery may have large load fluctuations or abnormal self-discharge and needs further adjustment. The basis for setting is to avoid excessive amplification or reduction of the abnormal trend value D when the battery SOC is in an extreme state (close to 0% or 100%). This value controls the influence of SOC on trend calculation within 10%.

[0035] The charge and discharge power adjustment submodule calls the abnormal charge and discharge trend value, compares it with the abnormal trend standard, adjusts the charge and discharge power output, and establishes abnormal charge and discharge correction information.

[0036] The charge and discharge power adjustment submodule calls the calculated abnormal charge and discharge trend value First, compare the abnormal trend standard to determine whether the abnormal charge and discharge trend exceeds the normal range. If the set threshold is exceeded, the charging and discharging power of the battery cell is adjusted to reduce or stop the discharge of the battery cell, and the battery cell with a lower abnormal trend is selected for power replenishment. The system traverses the abnormal trend values ​​of all battery cells. And sort in ascending order, select The smallest unit performs power adjustment to ensure that the total charge and discharge power after adjustment meets Constraints, in the calculation process, assume that the current charging pile demand kW, the abnormal charge and discharge trend value and maximum discharge power of a certain energy storage unit are shown in Table 4: Table 4 Abnormal charge and discharge trend and maximum discharge power of battery cells ; Among them, the abnormal trend standard is set based on the following: if the D value exceeds , it means that the battery internal resistance fluctuation is too large, affecting the normal charging and discharging process. Therefore, when matching power distribution, battery cells with lower D values ​​are given priority to provide output power to ensure stable power matching.

[0037] See also Figure 6 , the power allocation optimization module includes: The power supply capacity acquisition submodule calls abnormal charge and discharge correction information to obtain photovoltaic power generation and grid power supply capacity, and calculates and obtains the total photovoltaic and grid power supply; The power supply capacity acquisition submodule calls abnormal charge and discharge correction information, first calling the current photovoltaic power generation power from the photovoltaic power generation system , and read the power supply management system to obtain the current power supply power of the power grid , photovoltaic power generation Measure the actual output voltage of the PV panels through the inverter and current , calculated as ; Grid power supply The power fed into the grid is measured by a smart meter or the dispatching system obtains the current power supply value. All acquired data is stored in the power supply database, and then the total power supply of photovoltaic and grid is calculated. ; For example, suppose the output voltage of the photovoltaic power generation component at a certain moment is , output current , then the photovoltaic power generation power kW, if the power supply power provided by the power supply management system is kW, the total power supply is calculated as: ; Finally, the total power supply of photovoltaic and grid is obtained kW.

[0038] The instantaneous power compensation calculation submodule calls the total power supply of photovoltaic and grid power, using the formula: ; Calculate and obtain the instantaneous power compensation demand; in, Represents the instantaneous power compensation demand, Represents the current load power demand, Represents photovoltaic power generation power, Represents the grid power supply, represents the current discharge rate of the energy storage system, is the discharge ratio weight factor; The instantaneous power compensation calculation submodule calls the calculated total photovoltaic and grid power supply, and first obtains the current load power demand from the load management system , calculate the instantaneous power compensation demand , calculated as: ; Among them, the current discharge ratio of the energy storage system Indicates the ratio of the current energy storage system discharge power to the maximum discharge power of the energy storage battery. The setting of this ratio is based on the discharge capacity limit of the battery, usually depending on the maximum safe discharge current provided by the battery manufacturer. And rated voltage ,therefore The calculation method is , this value changes with the battery state of charge (SOC). The discharge rate decreases at low SOC to ensure that the battery is not over-discharged; the discharge rate weight factor It is used to measure the impact of the discharge ratio on the compensation demand. It is usually set according to the system stability requirements. If the system hopes to reduce its reliance on the energy storage system, a lower weight is set, such as ; If energy storage is the main compensation source, a higher weight is set, such as ; Set the current load power demand kW, total power supply from photovoltaic and grid kW, current discharge power of the energy storage system kW, maximum discharge power kW, then calculate the discharge ratio ; If the system hopes to control the impact level of energy storage compensation demand at 10%, then set ; If the system wants to enhance the energy storage response capability, then set , this calculation example takes , the calculation process is as follows: ; Calculate the instantaneous power compensation requirement kW.

[0039] The power allocation adjustment submodule calls the instantaneous power compensation demand, adjusts the power supply ratio of the photovoltaic energy storage system, and establishes optimized power allocation parameters.

[0040] The power allocation adjustment submodule calls the calculated instantaneous power compensation demand First, compare the available power of the current energy storage system to determine whether it can fully compensate for the power demand. If the remaining discharge capacity of the energy storage system is greater than or equal to , then directly adjust the energy storage system power output to compensate for the demand. If the remaining discharge capacity is less than , the power output ratio of the photovoltaic system and the power grid is adjusted to allocate the compensation demand in the best way; in the specific execution process, the remaining discharge capacity of the current energy storage system is read , and perform power adjustment calculation, assuming the maximum discharge power of the energy storage system kW, current discharge power kW, then the remaining discharge capacity ;because kW greater than kW, so the energy storage system can fully compensate for the power demand. The system adjusts the discharge power of the energy storage system from 10 kW to 24.15 kW, and finally establishes the optimized power allocation parameters so that the energy storage system can undertake the power compensation task.

[0041] The above are only preferred embodiments of the present invention and are not intended to limit the present invention in other forms. Any technician familiar with the profession may use the technical contents disclosed above to change or modify them into equivalent embodiments with equivalent changes and apply them to other fields. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A power supply control system for a photovoltaic energy storage charging pile, characterized in that: The system comprises: The load power analysis module obtains the load power demand of the photovoltaic energy storage charging pile, calculates the load fluctuation amplitude according to the load power change per unit time, determines the load power fluctuation level according to the power change rate, and establishes the load power fluctuation classification information; The energy storage battery pack management module calculates the available capacity of the battery unit based on the load power fluctuation division information, identifies the rechargeable battery unit and the dischargeable battery unit, selects the energy storage battery unit that meets the charging and discharging conditions in combination with the health status of the battery unit, and generates a list of rechargeable and dischargeable battery units; The charge and discharge dynamic control module calls the list of chargeable and dischargeable battery cells and the load power fluctuation division information, detects the internal resistance of the battery cells, calculates the charge and discharge priority of the cells, adjusts the charge and discharge sequence, optimizes the charge and discharge power output, and generates the charge and discharge power matching information of the energy storage unit; The abnormal charge and discharge correction module calls the charge and discharge power matching information of the energy storage unit, obtains the dynamic change data of the internal resistance of the battery pack, calculates the internal resistance change rate, sets the abnormal internal resistance fluctuation threshold, determines whether there is abnormal charge and discharge behavior, adjusts the charge and discharge power output, and generates abnormal charge and discharge correction information.

2. The power supply control system of the photovoltaic energy storage charging pile according to claim 1 is characterized in that: The load power fluctuation classification information includes load fluctuation rate, load change amplitude, power demand change trend and charging pile load classification; the list of rechargeable battery units includes rechargeable battery unit number, dischargeable battery unit number, battery unit available capacity and battery unit health status; the energy storage unit charge and discharge power matching information specifically includes unit output power, unit input power, unit charge and discharge priority and battery balanced charge and discharge parameters; the abnormal charge and discharge correction information includes abnormal internal resistance change, abnormal charge and discharge adjustment amplitude, corrected power compensation coefficient and battery internal resistance stability judgment value.

3. The power supply control system of the photovoltaic energy storage charging pile according to claim 1 is characterized in that: The load power analysis module comprises: The instantaneous power monitoring submodule obtains the load power demand of the photovoltaic energy storage charging pile, collects the output current of the charging gun, obtains the voltage value of the DC bus, and calculates the instantaneous power value; The load fluctuation calculation submodule calls the instantaneous power value, calculates the change in load power per unit time, and determines the load fluctuation amplitude based on the change, and uses the formula: ； Calculate and obtain the load power fluctuation value; in, Represents the load power fluctuation value, Representative The instantaneous power at the moment, represents the number of time slices during the computation period, Represents the instantaneous power change between adjacent time slices, Representative The timestamp of the moment, is the time decay factor, is the base of natural logarithms; The power demand state screening submodule calls the load power fluctuation value, divides the charging pile power demand state into multiple levels according to a preset fluctuation level classification standard, and establishes load power fluctuation classification information.

4. The power supply control system of the photovoltaic energy storage charging pile according to claim 1, characterized in that: The energy storage battery pack management module includes: The power state acquisition submodule acquires the remaining power percentage of the energy storage battery group based on the load power fluctuation division information, and calculates and acquires the available capacity of the battery unit; The battery cell screening submodule calls the available capacity of the battery cell, identifies the chargeable battery cell and the dischargeable battery cell according to the remaining power percentage threshold, and uses the formula based on the health status of the battery cell: ； Calculate and obtain the charging and discharging adaptability index of the battery unit; in, Represents the battery cell charge and discharge adaptability index, Represents the available capacity of the battery cell, Represents the minimum available capacity threshold. Represents the maximum available capacity. Represents the health status of the battery cell, is the health status attenuation factor, represents the base of natural logarithms; The chargeable and dischargeable unit generation submodule calls the battery unit charge and discharge adaptability index, screens energy storage battery units that meet the charge and discharge conditions according to a preset adaptability threshold, and establishes a list of chargeable and dischargeable battery units.

5. The power supply control system of the photovoltaic energy storage charging pile according to claim 1, characterized in that: The charging and discharging dynamic control module includes: The battery cell status detection submodule calls the list of chargeable and dischargeable battery cells and the load power fluctuation division information, detects the internal resistance of the battery cell, and obtains the impedance information of the battery cell; The charge and discharge priority calculation submodule calls the impedance information of the battery cell, combines the remaining power of the battery cell, and uses the formula: ； Calculate and obtain the charge and discharge priority value; in, Represents the charge and discharge priority value, Represents the remaining power of the battery cell, Represents the minimum power threshold, represents the internal resistance of the battery cell, Represents the power balance reference value set by the energy storage system. Represents the power balancing factor, is the base of natural logarithms; The power matching adjustment submodule calls the charging and discharging priority value and the load power fluctuation division information, adjusts the charging and discharging sequence, adjusts the charging and discharging power output in combination with the discharge demand of the charging pile and the load power fluctuation, and establishes the charging and discharging power matching information of the energy storage unit.

6. The power supply control system of the photovoltaic energy storage charging pile according to claim 1, characterized in that: The abnormal charge and discharge correction module includes: The internal resistance change detection submodule calls the charging and discharging power matching information of the energy storage unit, obtains the dynamic change data of the internal resistance of the battery pack, extracts the internal resistance change amount per unit time, and calculates and obtains the internal resistance change rate of the battery pack; The abnormal charge and discharge judgment submodule calls the battery pack internal resistance change rate, sets the abnormal internal resistance fluctuation threshold, judges whether there is abnormal charge and discharge behavior, and uses the formula: ； Calculate and obtain abnormal charge and discharge trend values; in, Represents the abnormal charge and discharge trend value, Represents the internal resistance of the battery pack at the current moment, Represents the internal resistance of the battery pack at the previous moment, represents the time interval, Represents the remaining battery power ratio. is the power impact factor, represents the base of natural logarithms; The charge and discharge power adjustment submodule calls the abnormal charge and discharge trend value, compares it with the abnormal trend standard, adjusts the charge and discharge power output, and establishes abnormal charge and discharge correction information.

7. The power supply control system of the photovoltaic energy storage charging pile according to claim 1, characterized in that: The system also includes a power allocation optimization module; The power allocation optimization module calls the abnormal charge and discharge correction information, obtains the photovoltaic power generation power and the power supply capacity of the power grid, calculates the instantaneous power compensation demand, adjusts the power supply ratio of the photovoltaic energy storage system, and generates optimized power allocation parameters; The optimized power allocation parameters specifically refer to the photovoltaic power supply ratio, grid compensation power, energy storage system allocation power and power regulation response time.

8. The power supply control system of the photovoltaic energy storage charging pile according to claim 7, characterized in that: The power allocation optimization module comprises: The power supply capacity acquisition submodule calls the abnormal charge and discharge correction information, obtains the photovoltaic power generation power and the power supply capacity of the power grid, and calculates and obtains the total photovoltaic and power grid power supply; The instantaneous power compensation calculation submodule calls the total amount of photovoltaic and grid power supply, using the formula: ； Calculate and obtain the instantaneous power compensation demand; in, Represents the instantaneous power compensation demand, Represents the current load power demand, Represents photovoltaic power generation power, Represents the grid power supply, represents the current discharge rate of the energy storage system, is the discharge ratio weight factor; The power allocation adjustment submodule calls the instantaneous power compensation demand, adjusts the power supply ratio of the photovoltaic energy storage system, and establishes optimized power allocation parameters.

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