Photovoltaic power storage intelligent battery pack management system based on intelligent regulation and control

Abstract

The invention relates to the field of photovoltaic technology, in particular to a photovoltaic power storage intelligent battery pack management system based on intelligent regulation and control, which is characterized in that a mobile battery vehicle carries a plurality of independent drawer type battery packs, is provided with positive and negative relays, is connected with a bus through a low-resistance copper bar, and is automatically conducted with an electric equipment interface through a power conversion connector after the battery packs are connected in series; each battery pack is provided with an independent sensor node, data of each drawer type battery pack is obtained through the sensor nodes, all the nodes are connected in series through twisted-pair shielded wires, and multi-node communication is achieved based on a CAN protocol; according to the real-time electricity demand, an optimal drawer type battery pack combination is dynamically selected by applying a greedy algorithm, and a BMS host controls the on-off states of a plastic shell switch, an air switch and a relay array according to a decision result; an emergency stop protection mechanism is arranged and comprises DI1 and DO2. Each drawer type battery pack is an independent energy storage unit, so that a single battery pack can be conveniently maintained, overhauled and replaced, and the work of other battery packs is not influenced.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic technology, and specifically relates to an intelligent battery pack management system for photovoltaic energy storage based on intelligent regulation. Background Art

[0002] With the accelerating transformation of the global energy structure towards cleaner and lower-carbon, as a core renewable energy technology, the installed capacity of photovoltaic power generation continues to grow. The photovoltaic energy storage vehicle emerges as a mobile energy storage unit in the integrated photovoltaic energy storage system. It can achieve flexible transportation and distribution of electric energy and can be widely used in scenarios such as emergency power supply, distributed energy access, and power supply guarantee in remote areas.

[0003] The photovoltaic energy storage vehicle converts the solar energy absorbed by the photovoltaic into electric energy and stores it in the battery pack inside the vehicle, and uses a truck to transport it to the location of the power consumption warehouse. The power consumption warehouse is the core terminal facility integrating power reception and distribution functions, providing stable power support for surrounding areas, industrial equipment, public facilities, etc. When the photovoltaic energy storage vehicle and the power consumption warehouse cooperate, the automatic plugging device equipped in the power consumption warehouse can achieve rapid and accurate docking. After the photovoltaic electric energy transported by the battery vehicle is converted by the power consumption warehouse, it can not only meet the charging needs of its own energy storage unit, but also supply power to surrounding loads through the output port, forming a closed-loop system of "mobile energy storage - fixed power supply", effectively improving the flexibility and sustainability of power supply.

[0004] However, the existing photovoltaic energy storage vehicles still face many challenges in actual applications. One of the key problems lies in the charge and discharge management of the battery pack, specifically manifested as follows: 1. It is difficult to dynamically adapt to the fluctuation of the power grid load: During peak loads, the battery energy storage system may have problems such as insufficient capacity or over-discharge, resulting in power supply interruption or shortened equipment life; during low-load periods, the fixed energy storage configuration is likely to cause equipment idleness, resulting in waste of resources.

[0005] 2. The battery life is shortened: The battery cycle life is limited by an unreasonable charge and discharge strategy, further pushing up the comprehensive cost. Summary of the Invention

[0006] The present invention aims at the technical problems existing in the prior art and provides an intelligent battery pack management system for photovoltaic energy storage based on intelligent regulation.

[0007] The technical solution for the present invention to solve the above technical problems is as follows: An intelligent battery pack management system for photovoltaic energy storage based on intelligent regulation, comprising: Battery pack module: The mobile battery vehicle is equipped with multiple independent drawer-type battery packs, equipped with positive and negative relays, connected to the bus through low-resistance copper bars. After the battery packs are connected in series, they are automatically conducted with the interface of the electrical equipment through the battery swapping connector; Data acquisition and transmission module: Each battery pack is equipped with an independent sensor node. The data of each drawer-type battery pack is obtained through the sensor node. Each node is connected in series through a twisted shielded wire, and multi-node communication is realized based on the CAN protocol; BMS host control module: According to the real-time power consumption demand, the greedy algorithm is used to dynamically select the optimal combination of drawer-type battery packs. According to the decision result, the BMS host controls the switch states of the molded case switch, air switch and relay array; Protection module: An emergency stop protection mechanism is provided, including DI1 and DO2. When the DI1 detects an emergency stop signal, DO2 outputs a high level to light up the fault lamp, and at the same time sends a CAN emergency stop frame to all drawer-type battery packs to quickly cut off the connection between the battery pack and the charge and discharge circuit.

[0008] In a preferred embodiment, the battery pack module converts the solar energy absorbed by the photovoltaic into electrical energy and stores it on the drawer-type battery packs in the mobile battery vehicle. The mobile battery vehicle is equipped with multiple drawer-type battery packs. Each drawer-type battery pack is an independent energy storage power supply. Each drawer-type battery pack is independently configured with a charging relay and a discharging relay. The relay coil is controlled by the BMS host through a ULN2803 driver chip, and the signal is isolated by an optocoupler to prevent strong electrical interference. The main circuit is connected to the central bus through a low-resistance copper bar to realize the convergence and distribution of electrical energy. A pre-charge relay and a pre-charge resistor are configured. When closing, the pre-charge resistor is used to limit the inrush current. When it is detected that the voltage at the P+ terminal reaches 90% of the battery voltage, the pre-charge relay is disconnected and the positive relay is closed to ensure shock-free access.

[0009] In a preferred embodiment, the data acquisition and transmission module connects the input end of the high-precision voltage transmission line in parallel to the positive and negative electrodes of each single cell of the drawer-type battery pack. The power line and the signal line are separated and routed using a four-wire system to reduce the voltage division error caused by the line resistance. The input end of the voltage sensor is connected to the total positive / negative terminal of the battery pack, and the output signal is connected to the signal conditioning chip through an RC filter circuit. The output voltage range is adjusted to 0-3.3V compatible with the ADC channel of the BMS host through a gain resistor. The magnetic core of the Hall current sensor passes through the charge and discharge loop copper bar of the battery pack to ensure that the current direction is consistent with the direction marked on the sensor. The analog signal output by the Hall current sensor is connected to the ADC channel of the BMS host. The CAN_H and CAN_L signal lines of each sensor node are sequentially connected in series using a twisted shielded cable, and a 120Ω terminal resistor is connected in parallel at both ends of the CAN bus. No resistor is connected to the intermediate nodes. A high-speed optocoupler isolation is added to the CAN interface on the BMS host side to improve the anti-interference ability and ensure that all nodes share the same ground. An isolated power supply is used to power the sensors to avoid ground loop interference. The baud rate of all sensor nodes is unified, and a unique CAN ID is assigned to each sensor node. Multi-node arbitration is achieved through the CAN controller of the BMS host. A test frame is injected at both ends of the bus using a CAN analyzer to monitor the node response time. The measured values of the sensors are compared with the CAN transmission values at the BMS host end to ensure that the voltage error is less than ±0.5%. The collected voltage and current data are subjected to a moving average to eliminate noise interference. A threshold is set, and when an abnormal value is detected, it is marked and excluded. For voltage data, let the collected voltage value be V, and the rated voltage be , the upper voltage threshold is , the lower voltage threshold is , when V > < , it is marked as an abnormal value and excluded. When , the data is retained. For current data, let the collected current value be , the rated voltage is , the upper voltage threshold is , the lower voltage threshold is , when > < , it is marked as an abnormal value and excluded. When , the data is retained. In the static state of the battery pack, the initial SOC is obtained by looking up the table according to the voltage value using the open-circuit voltage method. The charge and discharge current of the drawer-type battery pack is obtained in real time, the rated capacity of the drawer-type battery pack is determined, the charge and discharge efficiency is determined according to the charge and discharge state of the drawer-type battery pack, and the initial SOC is calculated using the ampere-hour integration method. The specific calculation formula is as follows: , using the ampere-hour integration method to calculate the initial SOC, the specific calculation formula is as follows: ; Among them, represents the state of charge at time t, represents the initial time of the state of charge, represents the rated capacity of the battery, represents the current value at discrete time . represents the time interval between two adjacent discrete times. Start timing and voltage detection, and trigger the open-circuit voltage method to correct the SOC process every 5 minutes. When triggering the correction process, pause the calculation of the ampere-hour integration method, measure the open-circuit voltage of the drawer-type battery pack, obtain the new SOC value through look-up table, and use it as the new initial value of the ampere-hour integration method , continue with the ampere-hour integration calculation, and adjust the charge and discharge efficiency according to the battery temperature , and regularly update the actual capacity of the battery through a full charge and discharge cycle .

[0010] In a preferred embodiment, the BMS host control module monitors the voltage at the P+ terminal in real time through a voltage dividing resistor network composed of a pull-up resistor R1 and a pull-down resistor R2, and calculates the actual voltage value according to the voltage division principle. Assume that the voltage dividing resistor network consists of a pull-up resistor and a pull-down resistor The voltage monitored by the BMS host is Then the actual voltage value The calculation formula is as follows: ; The voltage dividing signal is connected to the 12-bit ADC channel of the BMS host through an RC filter circuit, continuously comparing the monitored voltage at the P+ terminal with the battery voltage. When the voltage at the P+ terminal reaches 90% of the battery voltage, the BMS host controls the switching state of the relevant relay through the ULN2803 driver chip and the optocoupler isolation circuit. When charging, disconnect the main relay and close the trickle charging relay. When discharging, trigger the DO2 port to light up the yellow warning light and send a status signal through the CAN bus. The BMS host communicates with external devices through the RS485 interface, obtains the power demand data in real time, and determines the power scenario after analysis by the built-in CAN controller of the STM32F407: In the low-power scenario, read the SOC and single-cell voltage data of each battery pack from the CAN bus through the greedy algorithm, and screen out > 90% and the voltage difference threshold = 1% of the drawer-type battery packs, and preferentially activate the first 1-2 groups. In the high-power scenario, select > 70% of the battery packs, where represents the SOC threshold for battery pack participation in activation screening in the low-power scenario. Monitor the charge and discharge loop current through a Hall current sensor, according to The calculated result distributes the load current, and each battery pack discharge relay is controlled by the BMS topic through an independent optocoupler isolation channel to ensure synchronous response.

[0011] Low-power demand scenario: The BMS host retrieves the SOC data and single-cell voltage data of each drawer-type battery pack, and filters out > 90% and the voltage difference threshold = 1% of the drawer-type battery packs. Using the greedy algorithm, the battery packs with high power and stable voltage are preferentially selected. Suppose there are n battery packs in total , and the state of charge of each battery pack is , and the average single-cell voltage is . Calculate the average value of the voltages of all drawer-type battery packs. The specific calculation formula is as follows: ; Among them, represents the average value of the voltages of the drawer-type battery packs, and filters out the battery packs that meet the conditions > and | | < . These battery packs form the candidate set CAND. Define a comprehensive evaluation value (j ) for each candidate group , which is used to measure its priority as a discharge combination. Considering the historical usage times and the health status of the drawer-type battery packs, the specific calculation formula of the comprehensive evaluation value is as follows: ; Among them, , represent the weight coefficients. Adjust the weights according to actual needs to balance the influence of historical usage times and health status. Select the battery packs with the top 1-2 comprehensive evaluation values from the candidate set CAND as the discharge combination; High-power demand scenario: Suppose there are n battery packs in total , and set the state of charge threshold under the high-power scenario as > 70% to filter out the drawer-type battery packs that meet the conditions > . These battery packs form the discharge combination set DISCH. After determining the discharge combination set DISCH, to ensure the coordinated discharge of each drawer-type battery pack, it is necessary to ensure that the output currents of each battery pack are distributed in a certain proportion. Suppose the total load current demand is , there are m battery packs in the discharge combination set DISCH, and the maximum output current capacity of the kth battery pack is , then the current allocated to the k-th battery pack The specific calculation formula is as follows: ; Send corresponding current control signals to each drawer-type battery pack through the CAN bus to achieve coordinated discharge and meet the high-power power consumption requirements; According to the determined decision result of the drawer-type battery pack combination, the BMS host sends control instructions to the molded case switch, air switch and relay array. After receiving the instructions, the positive and negative relays of the target drawer-type battery pack close, connecting the target drawer-type battery pack to the charge and discharge circuit. The relays of non-target drawer-type battery packs remain open to isolate from the charge and discharge circuit, and continuously monitor the working status of each drawer-type battery pack, including current, voltage and temperature parameters. If any abnormality is found, the BMS host adjusts the drawer-type battery pack combination in time, disconnects the faulty drawer-type battery pack, and ensures the safe and stable operation of the system.

[0012] In a preferred embodiment, the DI1 port of the protection module is connected to the digital input channel of the BMS host through a normally closed emergency stop button. A 10kΩ pull-up resistor is connected in parallel at both ends of the button, and the line is laid with twisted pair shielded wire. When the emergency stop button is pressed, the contact is disconnected, causing the voltage of the DI1 port to rise to a high level, triggering the EXTI interrupt inside the STM32F407, recording the trigger time through the hardware timer and immediately executing the following circuit logic: The DO2 port outputs a high-level signal through the drive circuit to drive the fault indicator light and the buzzer. At the same time, an emergency stop frame is sent to the CAN bus through the high-speed optocoupler isolation module. The CAN bus uses differential two-wire transmission, and a 120Ω terminal resistor and an ESD protection device are configured on the host side to ensure that the stop instruction is transmitted to all battery packs within 50μs; The positive and negative relays of each drawer-type battery pack are configured with auxiliary normally open contacts. One end of the contact is connected to the +5V power supply, and the other end is connected to the DI port of the BMS host through a 1kΩ current-limiting resistor. When the relay is closed, the contact conducts, pulling down the level of the DI port. When it is disconnected, the contact is disconnected, and the DI port maintains a high level through the pull-up resistor. The BMS host scans the DI status by simulating the I2C protocol through the GPIO port, and compares the instruction status with the actual status: if the relay instruction of a certain battery pack is to be disconnected but the DI port remains low level, it is determined as a contact adhesion fault, and a secondary disconnection instruction is immediately sent through the hardware redundant channel, and at the same time, the solid-state relay is triggered to cut off the power supply circuit of the battery pack; Fault location is achieved through the address coding circuit: The DI port of each battery pack is connected in series with an 8-bit DIP switch. When the BMS host reads the DI status, it synchronously analyzes the address information, highlights the location of the faulty battery pack on the display screen, and sends the fault code to the EMS through the RS485 bus. After receiving the code, the EMS sends an alarm message containing GPS positioning to the operation and maintenance personnel through the TCP / IP protocol.

[0013] The beneficial effects of the present invention are as follows: Each drawer-type battery pack of the present invention is an independent energy storage unit and is configured with positive and negative relays, which can independently control charging and discharging, facilitating the maintenance, repair, and replacement of a single battery pack without affecting the operation of other battery packs. At the same time, it supports the flexible increase and expansion of battery packs to adapt to different energy storage requirements. By connecting to the central bus through low-resistance copper bars, the power loss during power transmission is significantly reduced, improving the energy transmission efficiency. The automatic conduction design of the sliding electrical contacts on the battery vehicle chassis and the interface of the power consumption compartment realizes the convenience and automation of power transmission, reduces manual operation, and improves the usage efficiency. Based on the optimized combination strategy of drawer-type battery packs, it can dynamically select the optimal battery pack combination according to real-time power consumption requirements. When the power demand is small, it preferentially uses battery packs with high power and stable voltage to reduce the charge and discharge times of low-power battery packs. When the power demand is large, it quickly activates the appropriate battery packs to ensure the reasonable distribution and efficient utilization of energy, improving the overall energy efficiency of the system and reducing the operating cost. The emergency stop protection mechanism can quickly output a high level to light up the fault lamp when detecting an emergency stop signal, and send an emergency stop frame to all drawer-type battery packs through the CAN bus to quickly cut off the connection between the battery pack and the charge and discharge circuit. The response time is short, which can effectively avoid the occurrence of safety accidents and ensure the safety of personnel and equipment. Brief Description of the Drawings

[0014] Figure 1 is the flow chart of the present invention; Figure 2 is the system block diagram of the present invention; Figure 3 is the circuit diagram for reading the magnitude of the main circuit current of the present invention; Figure 4 is the logic circuit diagram for judging whether the relay is switched on or off of the present invention; Figure 5 is the circuit diagram for controlling the external relay switch of the present invention; Figure 6 is the circuit diagram for measuring the P+ voltage of the present invention; Figure 7 is the RS485 bus diagram of the present invention. Detailed Embodiments

[0015] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0016] In the description of the present application, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality" means two or more, unless otherwise specifically defined.

[0017] In the description of the present application, the term "for example" is used to mean "serving as an example, illustration, or explanation". Any embodiment described as "for example" in the present application is not necessarily construed as being more preferred or having more advantages than other embodiments. In order for any person skilled in the art to implement and use the present invention, the following description is given. In the following description, details are set forth for the purpose of explanation. It should be understood that those of ordinary skill in the art can recognize that the present invention can be implemented without using these specific details. In other instances, well-known structures and processes are not elaborated in detail to avoid unnecessary details from obscuring the description of the present invention. Therefore, the present invention is not intended to be limited to the embodiments shown, but is consistent with the broadest scope that conforms to the principles and features disclosed in the present application.

[0018] As Figure 1 , this embodiment provides: a photovoltaic energy storage intelligent battery pack management system based on intelligent regulation, including: Battery pack module: The mobile battery vehicle is equipped with a plurality of independent drawer-type battery packs, equipped with positive and negative relays, connected to the bus through low-resistance copper bars. After the battery packs are connected in series, they are automatically conducted with the power consumption equipment interface through the power exchange connector; In this embodiment, it should be specifically noted that for the battery pack module, the battery pack module converts the solar energy absorbed by the photovoltaic into electrical energy and stores it in the drawer-type battery packs in the mobile battery vehicle. The mobile battery vehicle is equipped with a plurality of drawer-type battery packs, and each drawer-type battery pack is an independent energy storage power source. Each drawer-type battery pack is independently configured with a charging relay and a discharging relay. The relay coil is controlled by the BMS host through the ULN2803 drive chip, and the signal is isolated by an optocoupler to prevent strong electrical interference. The main circuit is connected to the central bus through low-resistance copper bars to achieve the convergence and distribution of electrical energy. A pre-charge relay and a pre-charge resistor are configured. When closing the switch, the inrush current is limited through the pre-charge resistor. When it is detected that the voltage at the P+ terminal reaches 90% of the battery voltage ( Figure 4) Disconnect the pre-charge relay and close the positive relay to ensure shock-free connection.

[0019] Data acquisition and transmission module: Each battery pack is equipped with an independent sensor node. Data of each drawer-type battery pack is obtained through the sensor node. Each node is connected in series through a twisted pair shielded wire, and multi-node communication is realized based on the CAN protocol. In this embodiment, it is necessary to specifically describe the data acquisition and transmission module. The input end of the high-precision voltage transmission line of the data acquisition and transmission module is connected in parallel to the positive and negative electrodes of each single battery of each drawer-type battery pack. The power line and the signal line are separated and routed using a four-wire connection method (two power lines VCC / GND + two signal lines S+ / S-), reducing the voltage division error caused by the line resistance. The input end of the voltage sensor is connected to the total positive / negative terminal of the battery pack, and the output signal is connected to the signal conditioning chip through an RC filter circuit. The output voltage range is adjusted to 0-3.3V compatible with the ADC channel of the BMS host through a gain resistor. The core of the Hall current sensor passes through the charge and discharge loop copper bar of the battery pack to ensure that the current direction is consistent with the direction marked on the sensor. The analog signal output by the Hall current sensor is connected to the ADC channel of the BMS host. The CAN_H and CAN_L signal lines of each sensor node are connected in series in sequence using a twisted pair shielded wire. A 120Ω terminal resistor is connected in parallel at each end node of the CAN bus, and no resistor is connected to the intermediate nodes. A high-speed optocoupler isolation is added to the CAN interface on the BMS host side to improve the anti-interference ability, ensure that all nodes share the same ground, use an isolated power supply to supply power to the sensors to avoid ground loop interference, unify the baud rate of all sensor nodes, assign a unique CAN ID to each sensor node, implement multi-node arbitration through the CAN controller of the BMS host, inject test frames at both ends of the bus using a CAN analyzer, monitor the node response time, compare the measured values of the sensors with the CAN transmission values at the BMS host side to ensure that the voltage error is less than ±0.5%, perform a moving average on the collected voltage and current data to eliminate noise interference, set thresholds (such as when the voltage exceeds the rated range by ±20%), mark and eliminate the abnormal values when detected. For voltage data, let the collected voltage value be V, the rated voltage be , the upper voltage threshold is , the lower voltage threshold is , when V > < it is marked as an abnormal value and eliminated. When it is retained. For current data, let the collected current value be , the rated voltage is , the upper voltage threshold is , the lower voltage threshold is , when > < Marked as outliers and removed when Keep the data. When the battery pack is in a static state, use the open-circuit voltage method to look up the table according to the voltage value to obtain the initial SOC, and obtain the charge and discharge current of the drawer-type battery pack in real time to determine the rated capacity of the drawer-type battery pack Determine the charge and discharge efficiency according to the charge and discharge state of the drawer-type battery pack Use the ampere-hour integration method to calculate the initial SOC. The specific calculation formula is as follows: ; where represents the state of charge at time t, represents the initial time of the state of charge, represents the rated capacity of the battery, represents the current value at discrete time , represents the time interval between two adjacent discrete times. Start timing and voltage detection, and trigger the open-circuit voltage method to correct the SOC process every 5 minutes. When triggering the correction process, pause the calculation of the ampere-hour integration method, measure the open-circuit voltage of the drawer-type battery pack, and obtain a new SOC value by looking up the table, which is used as the new initial value of the ampere-hour integration method , continue the ampere-hour integration calculation, and adjust the charge and discharge efficiency according to the battery temperature Regularly update the actual battery capacity through a full charge and discharge cycle .

[0020] It should be noted that the upper limit of the voltage threshold is , and the lower limit of the voltage threshold is .

[0021] It should be noted that multi-node arbitration is implemented through the non-destructive bit arbitration mechanism of the CAN controller. The CAN bus adopts the arbitration rule that the dominant bit takes precedence over the recessive bit. When multiple nodes send data simultaneously, the message IDs are compared bit by bit, and the message with more dominant bits in the ID obtains the bus control right, and the recessive bit nodes automatically back off without bus conflict handling.

[0022] BMS host control module: According to the real-time power consumption demand, use the greedy algorithm to dynamically select the optimal combination of drawer-type battery packs. The BMS host controls the switch states of the molded case switch, air switch and relay array according to the decision result; In this embodiment, it should be specifically noted that the BMS host control module. The BMS host control module monitors the voltage at the P+ terminal in real time through a voltage dividing resistor network composed of a pull-up resistor R1 and a pull-down resistor R2, and calculates the actual voltage value according to the voltage dividing principle. Assume that the voltage dividing resistor network consists of a pull-up resistor and a pull-down resistor is composed of, and the voltage monitored by the BMS host is then the actual voltage value The calculation formula is as follows: ; The voltage-dividing signal is connected to the 12-bit ADC channel of the BMS host through the RC filter circuit, continuously comparing the monitored voltage at the P+ terminal with the battery voltage. When the voltage at the P+ terminal reaches 90% of the battery voltage, the BMS host controls the switching state of the relevant relay through the ULN2803 driver chip and the optocoupler isolation circuit. When charging, the main relay is disconnected and the trickle charging relay is closed. When discharging, the DO2 port is triggered to light up the yellow warning light and the status signal is sent through the CAN bus. The BMS host communicates with external devices through the RS485 interface, obtains the power consumption demand data in real time, and determines the power scenario after analysis by the built-in CAN controller of the STM32F407: In the low-power scenario, the SOC and single-cell voltage data of each battery pack are read from the CAN bus through the greedy algorithm, and the > 90% and the voltage difference threshold = 1% of the drawer-type battery packs are selected, and the first 1-2 groups are preferentially activated. In the high-power scenario, the > 70% of the battery packs are selected, where represents the SOC threshold for battery pack participation in activation screening in the low-power scenario. The charge and discharge loop current is monitored through the Hall current sensor, and the load current is allocated according to the calculation result. The discharge relay of each battery pack is controlled by the BMS theme through an independent optocoupler isolation channel to ensure synchronous response.

[0023] It should be noted that the circuit design integrates multiple protection mechanisms: overvoltage protection, undervoltage protection, and surge suppression. At the same time, 120Ω terminal resistors are configured at the head and tail nodes of the CAN bus, an ADuM1200 optocoupler isolation module is added on the host side, and a 10μF electrolytic capacitor and a 100nF ceramic capacitor are connected in parallel at the power supply end to ensure the stable operation of the charge and discharge control circuit in a strong electromagnetic environment and achieve precise control and safety protection; Low-power demand scenario: The BMS host retrieves the SOC data and single-cell voltage data of each drawer-type battery pack, and selects the > 90% and the voltage difference threshold = 1% of the drawer-type battery packs. Using the greedy algorithm, the battery packs with high battery power and stable voltage are preferentially selected. Suppose there are n battery packs , and the state of charge of each battery pack is , and the average single-cell voltage is , calculate the average value of the voltages of all drawer-type battery packs. The specific calculation formula is as follows: ; Among them, Represents the average value of the voltage of the drawer - type battery pack, and filters out those that meet the conditions > and | | < of the battery packs. These battery packs form the candidate set CAND. Define a comprehensive evaluation value (j ) for each candidate group to measure its priority as a discharge combination, considering the historical usage times of the drawer - type battery pack and the health status . The specific calculation formula for the comprehensive evaluation value is as follows: ; ; Among them, , represent the weight coefficients. Adjust the weights according to actual needs to balance the influence of historical usage times and health status. Select the battery packs with the top 1 - 2 comprehensive evaluation values from the candidate set CAND as the discharge combination; High - power demand scenario: Suppose there are a total of n battery packs . Set the state - of - charge threshold in the high - power scenario to >70% and filter out the drawer - type battery packs that meet the conditions > . These battery packs form the discharge combination set DISCH. After determining the discharge combination set DISCH, to ensure the coordinated discharge of each drawer - type battery pack, it is necessary to ensure that the output currents of each battery pack are distributed in a certain proportion. Suppose the total load current demand is , there are m battery packs in the discharge combination set DISCH, and the maximum output current capacity of the k - th battery pack is . Then the current distributed to the k - th battery pack is calculated as follows: ; Send the corresponding current control signals to each drawer - type battery pack through the CAN bus to achieve coordinated discharge and meet the high - power electricity demand; The BMS host sends control instructions to the molded - case switch, air switch, and relay array according to the determined combination decision result of the drawer - type battery packs. After receiving the instructions, the positive and negative relays of the target drawer - type battery packs close, connecting the target drawer - type battery packs to the charge - discharge circuit, and the relays of the non - target drawer - type battery packs remain open to isolate from the charge - discharge circuit. Continuously monitor the working status of each drawer - type battery pack, including current, voltage, and temperature parameters. If an abnormality is found (such as excessive current or high temperature of a certain drawer - type battery pack), the BMS host adjusts the combination of drawer - type battery packs in time and disconnects the faulty drawer - type battery pack to ensure the safe and stable operation of the system.

[0024] It should be noted that the battery pack with high power and stable voltage is preferentially selected because in low-power scenarios, the single electricity consumption demand is small. Preferentially using batteries with sufficient power can reduce the frequent charge and discharge times of low-power batteries and reduce battery loss. At the same time, a small voltage difference can ensure a stable discharge process and reduce the life loss caused by internal imbalance of the battery pack, gradually achieving the goal of overall battery pack life balance from local optimal selection.

[0025] Protection module: It is equipped with an emergency stop protection mechanism, including DI1 and DO2. When DI1 detects an emergency stop signal, DO2 outputs a high level to light up the fault lamp, and at the same time sends a CAN emergency stop frame to all drawer-type battery packs, quickly cutting off the connection between the battery pack and the charge and discharge circuit; In this embodiment, it should be noted that for the protection module, the DI1 port of the protection module is connected to the digital input channel of the BMS host through a normally closed emergency stop button, and a 10kΩ pull-up resistor is connected in parallel at both ends of the button (ensuring that the DI1 port is at a low level under normal conditions). The line is laid with twisted pair shielded wire. When the emergency stop button is pressed, the contact is disconnected, causing the voltage of the DI1 port to rise to a high level, triggering the EXTI interrupt inside the STM32F407, recording the trigger time through the hardware timer and immediately executing the following circuit logic: The DO2 port outputs a high-level signal through a drive circuit (composed of NPN / PNP transistors) to drive the fault indicator light and the buzzer, and at the same time sends an emergency stop frame to the CAN bus through a high-speed optocoupler isolation module. The CAN bus uses differential two-wire transmission, and a 120Ω terminal resistor and an ESD protection device are configured on the host side to ensure that the stop instruction is transmitted to all battery packs within 50μs; Auxiliary normally open contacts are configured for the positive and negative relays of each drawer-type battery pack. One end of the contact is connected to the +5V power supply, and the other end is connected to the DI port of the BMS host through a 1kΩ current-limiting resistor. When the relay is closed, the contact conducts, pulling down the DI port level. When it is disconnected, the contact is disconnected, and the DI port maintains a high level through the pull-up resistor. The BMS host scans the DI status by simulating the I2C protocol through the GPIO port at a 100ms cycle, comparing the instruction status with the actual status: If the relay instruction of a certain battery pack is to be disconnected but the DI port remains at a low level continuously, it is determined as a contact adhesion fault, and a secondary disconnection instruction is immediately sent through the hardware redundant channel (independent CAN controller), and at the same time, the solid-state relay is triggered to cut off the power supply circuit of the battery pack; Fault location is achieved through an address coding circuit: An 8-bit DIP switch is connected in series to the DI port of each battery pack. When the BMS host reads the DI status, it synchronously analyzes the address information, highlights the location of the faulty battery pack on the display screen, and sends a fault code to the EMS through the RS485 bus. After receiving the code, the EMS sends an alarm message containing GPS positioning to the operation and maintenance personnel through the TCP / IP protocol.

[0026] It should be noted that in the circuit design, a power monitoring module is integrated. When the power supply voltage of the BMS host is lower than 4.5V, the emergency stop logic is forcibly triggered to prevent control failure caused by the power supply. All digital input ports are configured with TVS diodes to suppress surge voltage and ensure the reliable operation of the protection circuit in the computing environment.

[0027] It should be noted that in the above embodiments, the descriptions of each embodiment have their own focuses. For the parts not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0028] Those skilled in the art should understand that the embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0029] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to the embodiments of the present invention. It should be understood that each flow and / or block in the flowchart and / or block diagram, as well as the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded computer, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the specified functions in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0030] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including instruction means that implement the specified functions in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0031] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are performed on the computer or other programmable device to generate a computer-implemented process. Thus, the instructions executed on the computer or other programmable device provide means for implementing the specified functions in Figure 1Steps of the functions specified in one process or multiple processes and / or boxes Figure 1 Steps of the functions specified in one box or multiple boxes.

[0032] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications to these embodiments once they learn the basic inventive concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications that fall within the scope of the present invention.

[0033] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A photovoltaic energy storage intelligent battery pack management system based on intelligent regulation, characterized in that Comprising: Battery pack module: The mobile battery vehicle is equipped with multiple independent drawer-type battery packs, with positive and negative relays, connected to the busbar through low-resistance copper bars. After the battery packs are connected in series, they are automatically connected to the interface of the electrical equipment through the battery swapping connector; Data acquisition and transmission module: Each battery pack is equipped with an independent sensor node. Data of each drawer-type battery pack is obtained through the sensor node. Each node is connected in series through a twisted pair shielded wire, and multi-node communication is realized based on the CAN protocol; BMS host control module: According to the real-time power consumption demand, the greedy algorithm is used to dynamically select the optimal combination of drawer-type battery packs. According to the decision result, the BMS host controls the switch states of the molded case switch, air switch and relay array; Protection module: An emergency stop protection mechanism is provided, including DI1 and DO2. When DI1 detects an emergency stop signal, DO2 outputs a high level to light up the fault lamp, and at the same time sends a CAN emergency stop frame to all drawer-type battery packs to quickly cut off the connection between the battery pack and the charge and discharge circuit.

2. The intelligent battery pack management system for photovoltaic energy storage based on intelligent regulation according to claim 1, wherein, The battery pack module converts the solar energy absorbed by the photovoltaic into electrical energy and stores it in the drawer-type battery pack in the mobile battery vehicle. The mobile battery vehicle is equipped with multiple drawer-type battery packs. Each drawer-type battery pack is an independent energy storage power supply. Each drawer-type battery pack is independently configured with a charging relay and a discharging relay. The relay coil is controlled by the BMS host through the ULN2803 driver chip, and the signal is isolated by an optocoupler to prevent strong electrical interference. The main circuit is connected to the central busbar through a low-resistance copper bar to realize the convergence and distribution of electrical energy. A pre-charge relay and a pre-charge resistor are configured. When closing, the pre-charge resistor is used to limit the inrush current. When it is detected that the voltage at the P+ terminal reaches 90% of the battery voltage, the pre-charge relay is disconnected and the positive relay is closed to ensure no impact access.

3. The intelligent battery pack management system for photovoltaic energy storage based on intelligent regulation according to claim 1, wherein The data acquisition and transmission module connects the input end of the high-precision voltage transmission line in parallel to the positive and negative electrodes of each single cell of the drawer-type battery pack, separates the power line and the signal line using a four-wire connection method to reduce the voltage division error caused by the line resistance, connects the input end of the voltage sensor to the total positive / negative terminal of the battery pack, and the output signal is connected to the signal conditioning chip through an RC filter circuit. The output voltage range is adjusted to 0-3.3V compatible with the ADC channel of the BMS host through a gain resistor. The core of the Hall current sensor passes through the charge and discharge loop copper bar of the battery pack, and the analog signal output by the Hall current sensor is connected to the ADC channel of the BMS host. The CAN_H and CAN_L signal lines of each sensor node are sequentially connected in series using a twisted shielded cable, and a 120Ω terminal resistor is connected in parallel at both ends of the CAN bus. No resistor is connected to the intermediate nodes. A high-speed optocoupler isolation is added to the CAN interface on the BMS host side to ensure that all nodes share the same ground. An isolated power supply is used to power the sensors, the baud rate of all sensor nodes is unified, a unique CAN ID is assigned to each sensor node, multi-node arbitration is achieved through the CAN controller of the BMS host, a test frame is injected at both ends of the bus using a CAN analyzer to monitor the node response time, and the measured values of the sensors are compared with the CAN transmission values at the BMS host end to ensure that the voltage error is less than ±0.5%. The collected voltage and current data are subjected to a moving average to eliminate noise interference, and thresholds are set. When an abnormal value is detected, it is marked and removed. For voltage data, let the collected voltage value be V, and the rated voltage be , the upper voltage threshold is , the lower voltage threshold is , when V > < , it is marked as an abnormal value and removed. When , the data is retained. For current data, let the collected current value be , the rated voltage is , the upper voltage threshold is , the lower voltage threshold is , when > < , it is marked as an abnormal value and removed. When , the data is retained.

4. An intelligent battery pack management system for photovoltaic energy storage based on intelligent regulation according to claim 3, characterized in that Abnormal value rejection. For voltage data, let the collected voltage value be V, and the rated voltage be , the upper voltage threshold is , the lower voltage threshold is . When V > < , it is marked as an abnormal value and rejected. When , the data is retained. For current data, let the collected current value be , the rated voltage is , the upper voltage threshold is , the lower voltage threshold is . When > < , it is marked as an abnormal value and rejected. When , the data is retained.

5. The intelligent battery pack management system for photovoltaic energy storage based on intelligent regulation according to claim 3, characterized in that, When the battery pack is in a static state, the initial SOC is obtained by looking up a table according to the voltage value using the open circuit voltage method, and the charge and discharge current of the drawer-type battery pack is obtained in real time , determine the rated capacity of the drawer-type battery pack , determine the charge and discharge efficiency according to the charge and discharge state of the drawer-type battery pack , calculate the initial SOC using the ampere-hour integration method, and the specific calculation formula is as follows: ； Among them, represents the state of charge at time t, represents the initial time state of charge, represents the rated capacity of the battery, represents the current value at discrete time ; represents the time interval between two adjacent discrete times. Start timing and voltage detection, and trigger the open circuit voltage method to correct the SOC process every 5 minutes. When triggering the correction process, pause the calculation of the ampere-hour integration method, measure the open circuit voltage of the drawer-type battery pack, obtain a new SOC value by looking up the table, and use it as the new initial value of the ampere-hour integration method , continue the ampere-hour integration calculation, and adjust the charge and discharge efficiency according to the battery temperature , and regularly update the actual capacity of the battery through a full charge and discharge cycle .

6. The intelligent battery pack management system for photovoltaic energy storage based on intelligent regulation according to claim 1, wherein, The BMS host control module monitors the voltage at the P+ terminal in real time through a voltage-dividing resistor network composed of a pull-up resistor R1 and a pull-down resistor R2, and calculates the actual voltage value according to the voltage-dividing principle. Let the voltage-dividing resistor network consist of the pull-up resistor and the pull-down resistor The voltage monitored by the BMS host is Then the actual voltage value The calculation formula is as follows: ； The divided voltage signal is connected to the 12-bit ADC channel of the BMS host through an RC filter circuit, continuously comparing the monitored voltage at the P+ terminal with the battery voltage. When the voltage at the P+ terminal reaches 90% of the battery voltage, the BMS host controls the switching state of the relevant relay through the ULN2803 driver chip and the optocoupler isolation circuit. When charging, the main relay is disconnected and the trickle charging relay is closed. When discharging, the DO2 port is triggered to light up the yellow warning light and the status signal is sent through the CAN bus. The BMS host communicates with external devices through the RS485 interface, real-time obtains the power demand data, and determines the power scenario after analysis by the built-in CAN controller of the STM32F407: In the low-power scenario, the SOC and single-cell voltage data of each battery pack are read from the CAN bus through the greedy algorithm, and the > 90% and the voltage difference threshold = 1% drawer-type battery packs, the first 1-2 groups are preferentially activated. In the high-power scenario, the > 70% battery packs are selected, where represents the SOC threshold for battery pack participation in activation screening in the low-power scenario. The charging and discharging loop current is monitored by a Hall current sensor, and the load current is allocated according to the calculation result. The discharge relay of each battery pack is controlled by the BMS theme through an independent optocoupler isolation channel.

7. An intelligent battery pack management system for photovoltaic energy storage based on intelligent regulation according to claim 6, characterized in that, Low-power demand scenario: The BMS host retrieves the SOC data and single-cell voltage data of each drawer-type battery pack, and filters out > 90% and the voltage difference threshold = 1% of the drawer-type battery packs. Using the greedy algorithm, priority is given to selecting the battery packs with high power and stable voltage. Suppose there are n battery packs in total , and the state of charge of each battery pack is , and the average single-cell voltage is . Calculate the average value of the voltages of all drawer-type battery packs. The specific calculation formula is as follows: ； Among them, represents the average value of the voltage of the drawer-type battery pack, and filters out those that meet the conditions > and | | < The battery packs form a candidate set CAND. For each candidate group (j ) define a comprehensive evaluation value , which is used to measure its priority as a discharge combination, considering the historical usage times and health status of the drawer-type battery pack. The specific calculation formula of the comprehensive evaluation value is as follows: ； Among them, and represent weight coefficients. Adjust the weights according to actual needs to balance the influence of historical usage times and health status, and select the battery packs with the top 1-2 comprehensive evaluation values from the candidate set CAND as the discharge combination.

8. An intelligent battery pack management system for photovoltaic energy storage based on intelligent regulation according to claim 6, characterized in that, High-power demand scenario: Suppose there are n battery packs in total , and set the state of charge threshold in the high-power scenario to > 70% to screen out the drawer-type battery packs that meet the conditions > . These battery packs form the discharge combination set DISCH. After determining the discharge combination set DISCH, to ensure the coordinated discharge of each drawer-type battery pack, it is necessary to ensure that the output currents of each battery pack are distributed in a certain proportion. Suppose the total load current demand is , there are m battery packs in the discharge combination set DISCH, and the maximum output current capacity of the k-th battery pack is , then the current allocated to the k-th battery pack is calculated as follows: ； Send corresponding current control signals to each drawer-type battery pack through the CAN bus to achieve coordinated discharge and meet the high-power power consumption demand.

9. The intelligent battery pack management system based on intelligent regulation for photovoltaic energy storage according to claim 6, wherein, According to the decision result of the determined combination of drawer-type battery packs, the BMS host sends control instructions to the molded case switch, air switch and relay array. After the positive and negative relays of the target drawer-type battery pack receive the instructions, they close, connecting the target drawer-type battery pack to the charge and discharge circuit. The relays of the non-target drawer-type battery packs remain disconnected to realize isolation from the charge and discharge circuit. Continuously monitor the working states of each drawer-type battery pack, including current, voltage and temperature parameters. If any abnormality is found, the BMS host timely adjusts the combination of drawer-type battery packs and disconnects the faulty drawer-type battery pack to ensure the safe and stable operation of the system.

10. A photovoltaic energy storage intelligent battery pack management system based on intelligent regulation according to claim 1, characterized in that, The DI1 port of the protection module is connected to the digital input channel of the BMS host through a normally closed emergency stop button. A 10kΩ pull-up resistor is connected in parallel at both ends of the button. The line is laid with a twisted pair shielded wire. When the emergency stop button is pressed, the contact is disconnected, causing the voltage at the DI1 port to rise to a high level, triggering the EXTI interrupt inside the STM32F407, recording the trigger time through the hardware timer and immediately executing the following circuit logic: The DO2 port outputs a high-level signal through the drive circuit to drive the fault indicator light and the buzzer. At the same time, it sends an emergency stop frame to the CAN bus through the high-speed optocoupler isolation module. The CAN bus uses differential two-wire transmission, and the host side is configured with a 120Ω terminal resistor and an ESD protection device; The positive and negative relays of each drawer-type battery pack are configured with auxiliary normally open contacts. One end of the contact is connected to the +5V power supply, and the other end is connected to the DI port of the BMS host through a 1kΩ current-limiting resistor. When the relay is closed, the contact conducts, and the level of the DI port is pulled low. When it is disconnected, the contact is disconnected, and the DI port maintains a high level through the pull-up resistor. The BMS host scans the DI status by simulating the 12C protocol through the GPIO port, and compares the command status with the actual status: If the relay command of a certain battery pack is to be disconnected but the DI port remains low, it is determined as a contact adhesion fault, and a secondary disconnection command is immediately sent through the hardware redundant channel. At the same time, the solid-state relay is triggered to cut off the power supply circuit of the battery pack.

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