Energy storage battery charging and discharging equalization control system and method
Patent Information
- Application Number
- CN202510536307.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-27
- Publication Date
- 2026-10-30
AI Technical Summary
[0037]本申请的技术方案，通过采集模块采集电池组内各单体电池的监测数据，运算模块基于采集到的监测数据，采用安时积分法、卡尔曼滤波法和开路电压法不同权重相结合的电池荷电状态估算方法，计算出电池组内各单体电池的荷电状态和健康状态，进而均衡模块根据荷电状态和健康状态结合主被动均衡策略，对电池组内各单体电池进行均衡控制，以解决电池组在充放电过程中的“木桶效应”问题，使得电池组的性能达到最佳状态，保证电池组利用率始终处于最高状态，从而提升储能电池整体的利用率，进而实现电池系统的重构和故障的早诊断、早处理，保障电池安全运行与寿命优化。
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Abstract
Description
Technical Field
[0001] This application relates to the field of energy storage battery technology, and in particular to an energy storage battery charge-discharge equalization control system and method. Background Technology
[0002] With the transformation of the global energy structure and the increasing demand for environmental protection, the development and utilization of renewable energy has become an important way for countries to supplement their energy supply. New energy sources, with their low-carbon and environmentally friendly characteristics, have become an important direction for global industrial transformation. Electrochemical energy storage, utilizing electrochemical principles to store and release electrical energy through charging and discharging processes, plays a vital role in renewable energy integration, grid peak shaving, and emergency power supply.
[0003] Among various energy storage methods, lithium-ion batteries stand out due to their mature technology, high energy density, and good cycle stability. During the operation of lithium battery energy storage systems, various faults can occur, among which excessive voltage differences between individual cells are a significant factor affecting the performance and safety of the battery pack. Excessive voltage differences not only reduce the efficiency of the battery pack and shorten its lifespan but can also cause overheating, thermal runaway, and even explosions, posing a serious threat to the safety of the power station. Extensive research has been conducted by academia and industry to address voltage difference faults in energy storage batteries. This research primarily focuses on the analysis of the causes of voltage difference faults and maintenance and management strategies.
[0004] During the charging and discharging process of energy storage batteries, due to differences in manufacturing processes and operating environments, the capacity and state of charge of individual battery cells within the battery pack gradually vary, leading to the "weakest link" effect. For example... Figure 1 As shown, during discharge, the amount of electricity that can be released from the battery pack depends on the individual battery cell with the smallest remaining charge. Figure 1 When the voltage of battery 4 reaches the lower cutoff voltage, even though the other batteries still have some charge, the BMS will control the battery pack to stop discharging for the overall safety of the battery pack. During the charging process, when the high-charge battery is fully charged, all batteries must stop charging for safety reasons, which prevents the battery pack from charging to its maximum capacity.
[0005] Currently, existing equalization technologies can effectively suppress inconsistencies between batteries. However, there is still no reliable and stable solution for the barrel effect caused by differences in battery cells during manufacturing, differences in aging, the influence of ambient temperature, and excessive battery voltage difference leading to overcharging or over-discharging of some battery cells. Summary of the Invention
[0006] To address the aforementioned issues, this application provides a charge-discharge equalization control system and method for energy storage batteries, which can resolve the "weakest link" problem in the charging and discharging process of the battery pack, enabling the battery pack to reach its optimal performance and ensuring that the battery pack utilization rate is always at its highest, thereby improving the overall utilization rate of the energy storage battery.
[0007] To achieve the above objectives, this application adopts the following technical solution:
[0008] In a first aspect, the present invention also provides a system for maximizing the utilization of an energy storage battery, comprising:
[0009] The data acquisition module is used to collect monitoring data from each individual cell in the battery pack and transmit the monitoring data to the computing module.
[0010] The calculation module is used to calculate the battery state of each individual cell in the battery pack based on the received monitoring data, and transmit the battery state of each individual cell in the battery pack to the equalization module.
[0011] The balancing module is also used to balance and control the individual cells in the battery pack based on the received battery state of each cell in the battery pack and the active and passive balancing strategies.
[0012] Furthermore, the acquisition module also includes: a voltage acquisition unit, a current acquisition unit, and a temperature acquisition unit;
[0013] The voltage acquisition unit connects the multi-cell detection chip that acquires the voltage of the circuit to each individual cell in the battery pack. An RC low-pass decoupling filter and a grounding filter capacitor are added to each input port of the multi-cell detection chip to acquire the voltage data of each individual cell in the battery pack and transmit the acquired voltage data to the computing module.
[0014] In the current acquisition unit, a high-precision current shunt detection chip for acquiring circuit current is connected to each individual cell in the battery pack, and a voltage reference chip is connected to the pin of the high-precision current shunt detection chip to acquire the current data of each individual cell in the battery pack and transmit the acquired current data to the computing module.
[0015] The temperature acquisition unit uses temperature sensors to sense the temperature of each individual cell in the battery pack in real time, collects temperature data of each individual cell in the battery pack, and transmits the collected temperature data to the computing module.
[0016] Furthermore, the state of charge and health status of each individual cell in the battery pack are calculated and transmitted to the equalization module.
[0017] Furthermore, the equalization module also includes: an equalization circuit switch module, a main control unit, and a drive circuit module;
[0018] The equalization circuit switching module includes an active equalization unit and a passive equalization unit. The active equalization unit is used to control the circuit switching between each individual cell in the battery pack and the common flying capacitor through a switching array built with multiple metal-oxide-semiconductor field-effect transistors, transferring energy from the individual cells with higher capacity to the individual cells with lower capacity. The passive equalization unit is used to control the switching of the load resistor connected in parallel across each individual cell in the battery pack through metal-oxide-semiconductor field-effect transistors, reducing the energy of the individual cells with higher capacity.
[0019] The main control unit is used to generate equalization control commands for each individual cell in the battery pack based on the received battery state of each individual cell in the battery pack and the active and passive equalization strategy, and send the commands to the drive circuit module; it is also used to execute the operation module to issue exit commands based on the state of charge and health of each individual cell in the battery pack.
[0020] The drive circuit module is used to drive and control the metal-oxide-semiconductor field-effect transistors in the equalization circuit switching module through the drive chip, based on the equalization control commands of the main control unit.
[0021] Furthermore, the main control unit is also used for:
[0022] The system compares the state of charge (SOC) values of each individual cell in the battery pack with the initial SOC values of each cell. Based on the range of the difference threshold, it generates corresponding balancing commands. If the difference is greater than 5%, active balancing is initiated; if the difference is less than 5% but greater than 1%, passive balancing is initiated; if the difference is less than 1%, balancing is stopped. After active balancing is initiated, the system will also continuously check whether the difference is less than 5%. When the difference reaches the threshold of less than 5% but greater than 1%, it switches to passive balancing; when the difference reaches less than 1%, it switches to stopping balancing.
[0023] Secondly, the present invention provides a method for maximizing the utilization of an energy storage battery, comprising:
[0024] The acquisition module collects monitoring data from each individual cell in the battery pack and transmits the monitoring data to the computing module;
[0025] Based on the received monitoring data, the calculation module calculates the battery state of each individual cell in the battery pack and transmits the battery state of each individual cell in the battery pack to the equalization module.
[0026] The balancing module performs balancing control on each individual cell in the battery pack based on the received battery state of each cell and a combination of active and passive balancing strategies.
[0027] Furthermore, based on the received monitoring data, the computing module calculates the battery state of each individual cell within the battery pack, including:
[0028] Based on the received monitoring data, the calculation module uses a battery state-of-charge estimation method that combines different weights of the ampere-hour integration method, the Kalman filter method, and the open-circuit voltage method to calculate the state of charge and health status of each individual cell in the battery pack.
[0029] Furthermore, the balancing module, based on the received battery state of each individual cell within the battery pack and combined with active and passive balancing strategies, performs balancing control on each individual cell within the battery pack, including:
[0030] The main control unit of the equalization module generates equalization control commands for each individual cell in the battery pack based on the received battery status of each cell in the battery pack and the active and passive equalization strategies, and sends the commands to the drive circuit module of the equalization module.
[0031] The driving circuit module of the equalization module performs equalization control on each individual cell in the battery pack based on the equalization control command of each individual cell in the battery pack.
[0032] Furthermore, the main control unit of the equalization module generates equalization control commands for each individual cell in the battery pack based on the received battery state of each cell and the active / passive equalization strategy, including:
[0033] The main control unit of the equalization module compares the state of charge (SOC) values of each individual cell in the battery pack with the initial SOC value of each cell. Based on the range of the difference threshold, it generates a corresponding equalization command. If the difference is greater than 5%, active equalization is initiated; if the difference is less than 5% but greater than 1%, passive equalization is initiated; if the difference is less than 1%, equalization is stopped. After active equalization is initiated, the system will also continuously check whether the difference is less than 5%. When the difference reaches the threshold of less than 5% but greater than 1%, it switches to passive equalization; when the difference reaches less than 1%, it switches to stop equalization.
[0034] Furthermore, the driving circuit module of the balancing module performs balancing control on each individual cell within the battery pack based on balancing control commands, including:
[0035] The driving circuit module of the equalization module controls the switching of metal-oxide-semiconductor field-effect transistors in the active equalization unit or the passive equalization unit in the equalization circuit switching module of the equalization module, based on the equalization control command of each individual cell in the battery pack.
[0036] The technical solution provided in this application has at least the following technical effects or advantages:
[0037] The technical solution of this application collects monitoring data of each individual cell in the battery pack through an acquisition module. Based on the collected monitoring data, the calculation module uses a battery state-of-charge estimation method that combines different weights of the ampere-hour integral method, Kalman filtering method, and open-circuit voltage method to calculate the state of charge and health status of each individual cell in the battery pack. Then, the balancing module performs balancing control on each individual cell in the battery pack according to the state of charge and health status and the active and passive balancing strategy to solve the "barrel effect" problem of the battery pack during the charging and discharging process, so that the performance of the battery pack reaches the optimal state and the utilization rate of the battery pack is always at the highest level. This improves the overall utilization rate of the energy storage battery, and enables the reconfiguration of the battery system and early diagnosis and handling of faults, ensuring safe operation and life optimization of the battery.
[0038] Other features and advantages of this application will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description
[0039] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0040] Figure 1 This is a schematic diagram of the "weakest link" effect of the energy storage battery during the charging and discharging process in this application.
[0041] Figure 2 This is a schematic diagram of the structure of a charge-discharge equalization control system for an energy storage battery according to an embodiment of this application;
[0042] Figure 3 This is a schematic diagram of the voltage acquisition circuit in an embodiment of this application;
[0043] Figure 4 This is a schematic diagram of the current acquisition circuit in an embodiment of this application;
[0044] Figure 5 This is a schematic diagram of the operation module structure in an embodiment of this application;
[0045] Figure 6 This is a schematic diagram of the circuit structure for active and passive equalization in the embodiments of this application;
[0046] Figure 7This is a schematic diagram of the drive circuit in an embodiment of this application;
[0047] Figure 8 This is a flowchart illustrating the active-passive balancing strategy in the embodiments of this application;
[0048] Figure 9 This is a flowchart illustrating a method for equalizing the charge and discharge of an energy storage battery according to an embodiment of this application. Detailed Implementation
[0049] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0050] Figure 2 A schematic diagram of a charge-discharge equalization control system for an energy storage battery provided in this application is shown in the figure, including:
[0051] The data acquisition module is used to collect monitoring data from each individual cell in the battery pack and transmit the monitoring data to the computing module.
[0052] The calculation module is used to calculate the battery state of each individual cell in the battery pack based on the received monitoring data, and transmit the battery state of each individual cell in the battery pack to the equalization module.
[0053] The balancing module is used to balance the individual cells in the battery pack based on the received battery state of each cell and the active and passive balancing strategies.
[0054] The technical solution of this application collects monitoring data of each individual cell in the battery pack, calculates the state of charge and health of each individual cell, and then performs balanced control on each individual cell in the battery pack based on the determined state of charge and health of each individual cell in the battery pack. This solves the "barrel effect" problem of the battery pack during the charging and discharging process, so that the performance of the battery pack reaches the optimal state and the utilization rate of the battery pack is always at the highest level, thereby improving the overall utilization rate of the energy storage battery.
[0055] It should be noted that, for ease of explanation, Figure 2 This example only illustrates the main modules of the energy storage battery charge-discharge equalization control system structure. In practical applications, the system may also include modules or components not shown in the figure; the system is not limited to the above-described module structure, but may also be other module structures that implement the above method embodiments.
[0056] The technical solution of this application will be further described below with reference to the accompanying drawings:
[0057] A battery module is an energy storage battery pack, which is a battery assembly formed by connecting multiple individual batteries in series, parallel, or series-parallel combinations. Each individual battery has independent charge-discharge characteristics and energy storage capacity. By rationally combining individual batteries, the battery pack can flexibly adjust the output voltage, current, and capacity according to different requirements, thereby providing a suitable power supply.
[0058] The data acquisition module transmits the monitoring data of each individual cell in the battery pack to the processing module via a serial peripheral interface (SPI). The battery monitoring data includes voltage, current, and temperature data. The data acquisition module includes voltage acquisition units, current acquisition units, and temperature acquisition units.
[0059] Voltage acquisition unit, i.e., voltage acquisition circuit, such as Figure 3 As shown, in the voltage acquisition circuit, the microcontroller unit chip for acquiring the voltage is connected to each individual cell in the battery pack. An RC low-pass decoupling filter and a grounding filter capacitor are installed at each input port of the multi-cell detection chip to acquire the voltage data of each individual cell in the battery pack and transmit the acquired voltage data to the processing module. Since acquiring the voltage of each individual cell in the battery pack requires a significant number of digital-to-analog converter interfaces, and ordinary microcontroller unit chips have limited resources, this application uses a multi-cell detection chip, such as the multi-cell battery pack monitor LTC6811. Noise is present during voltage acquisition. An RC low-pass decoupling filter and a grounding filter capacitor are added to each input port of the microcontroller unit chip. The RC low-pass decoupling filter reduces noise interference and suppresses potential high-energy transients. The grounding filter capacitor effectively suppresses battery voltage ripple and decouples the ripple noise to the GND terminal (the ground terminal in the circuit). The accuracy of the voltage acquisition via the digital-to-analog converter interface changes with variations in the R and C parameters. This can be verified through literature review and experiments to minimize errors. The microcontroller unit chip transmits the voltage data of each individual cell in the battery pack to the microcontroller unit in the computing module via a serial external interface, which is used for control judgment and calculation by the balancing module and the computing module.
[0060] Current acquisition unit, i.e., current acquisition circuit, such as Figure 4As shown, in the current acquisition circuit, a high-precision current shunt detection chip is connected to each individual cell in the battery pack. A voltage reference chip is connected to the pins of the high-precision current shunt detection chip to acquire the current data of each individual cell in the battery pack and transmit the acquired current data to the processing module. The chip for acquiring the current circuit uses a high-precision current shunt detection chip, such as the INA282. The pins of the chip for acquiring the current circuit can also be connected to the output pins of a voltage reference chip (such as REF3225) to improve the stability of the current acquisition circuit. The chip for acquiring the current circuit outputs the acquired current value through its output pins, transmitting the acquired current data of each individual cell in the battery pack to the microcontroller unit in the processing module for control judgment and calculation by the equalization module and the operation module.
[0061] The temperature acquisition unit uses a temperature sensor (PT100 platinum resistance thermometer) to sense the temperature of each individual cell in the battery pack in real time. The battery temperature is converted into an electrical signal, which is then filtered, amplified, and isolated to eliminate noise and high voltage interference. The signal is then converted into a digital signal by a high-precision ADC. The accuracy is improved by combining nonlinear correction and temperature compensation algorithms. Finally, the data is transmitted to the microcontroller unit of the computing module through communication protocols such as CAN / I2C. The microcontroller monitors the temperature distribution in real time and triggers graded protection (such as over-temperature descent and circuit disconnection) to ensure safe operation and lifespan optimization of the battery.
[0062] The data acquisition module also includes an internal resistance acquisition unit, which is used to acquire the internal resistance of each individual cell in the battery pack and transmit the acquired internal resistance data to the computing module; and a power acquisition unit, which is used to acquire the power of each individual cell in the battery pack and transmit the acquired power data to the computing module. The methods for acquiring internal resistance and power are relatively conventional and will not be described in detail here.
[0063] Based on the received monitoring data of each individual cell in the battery pack, the calculation module uses a battery state-of-charge estimation method that combines different weights of the ampere-hour integration method, Kalman filtering method, and open-circuit voltage method to calculate the state of charge and state of health of each individual cell in the battery pack. This information is then transmitted to the equalization module. A schematic diagram of the calculation module is shown below. Figure 5As shown, the system includes a microcontroller unit and a serial port controller (SPI). The microcontroller unit includes a SOC / SOH (state of charge, SOC represents the battery's state of charge, SOH represents the battery's state of health) calculation unit. The calculation module configures the communication pins through its built-in software, writes SPI code according to the SPI timing diagram, and verifies the timing logic through simulation software. The SOC / SOH calculation unit uses a battery SOC estimation method that combines different weights of the ampere-hour integration method, Kalman filtering method, and open-circuit voltage method to calculate the state of charge and state of health of each individual cell in the battery pack. Before the calculation module performs the calculations, the initial SOC0 of each individual cell in the battery pack is estimated using the open-circuit voltage method. The initial SOC0 of each individual cell is calculated using the open-circuit voltage (OCV) curve between the battery voltage and SOC. Then, the received battery current and voltage data are sent to the calculation module for SOC calculation. The SOC calculation unit integrator accumulates the values to obtain the capacity C value of each individual cell (the ratio of the amount of electricity the battery can charge or discharge within a specific time to the battery's rated capacity). Finally, the calculated values of each individual cell are... The SOC value is transmitted to the main control unit of the equalization module; the SOH calculation first collects key data such as battery cell voltage, internal resistance, temperature, charge / discharge current, and capacity in real time through the acquisition unit. Then, it combines the ampere-hour integration method (statistically calculating the cumulative charge / discharge capacity) and the internal resistance method (monitoring changes in ohmic and polarization internal resistance) for preliminary estimation. Under constant current charge / discharge conditions, the battery internal resistance decay can be quantified by the voltage recovery (such as the voltage difference between 1 second and 150 seconds after discharge stops). Kalman filtering is used to correct the data, and historical correction parameters are introduced to optimize the calculation results (taking capacity as an example: C). k =C k-1 +ΔC+w k In the formula, C k C represents the current capacity. k-1 Let w represent the previous capacity, ΔC be the rate of change of capacity, and w be the value of w. kThe system modeling uncertainty is represented by a Gaussian distribution. The health status is ultimately determined by the ratio of the actual capacity to the rated capacity of each individual battery cell (SOH = actual capacity / rated capacity × 100%). Simultaneously, the SOH is determined to be zero by combining the charge / discharge cycle count (one charge / discharge cycle is counted, and the cycle count is triggered by a cumulative capacity threshold) and the cell voltage difference. If the charge / discharge cycle is abnormal or the cell voltage difference is greater than 0.2, the SOH is determined to be zero. Finally, the obtained SOH value is transmitted to the main control unit of the equalization module. The main control unit of the equalization module, combined with the active / passive equalization strategy, issues equalization commands or shielding commands to perform equalization control or activation / deactivation control on each individual battery cell within the battery pack. The SOC / SOH operation unit is internally composed of main modules such as a half-adder, multiplier, accumulator, and counter. The counter is used to count the number of charge-discharge cycles (counted by clock pulses) and, together with the half-adder (a basic logic unit for processing binary signals), performs low-level logic operations on battery state switching. The accumulator performs ampere-hour integration (accumulated charge-discharge capacity) through an integrator circuit, weights and fuses voltage, temperature, and internal resistance data, and, together with the multiplier (performs parameter correction, multiplying the internal resistance attenuation coefficient by the current) to complete the dynamic modeling of capacity decay. Finally, the health status is output using the formula SOC = actual capacity / rated capacity × 100%. The multiplier is used for covariance matrix operations in the Kalman filter algorithm.
[0064] The equalization module includes an equalization circuit switch module, a drive circuit module, a power supply module, and a main control unit. The circuit of the equalization circuit switch module is as follows: Figure 6 As shown, the circuit contains multiple MOSFETs. The drive circuit module, based on the equalization control instructions of the main control unit, increases the main control unit's drive capability over the MOSFETs through a driver chip. The driver chip, EG2133, can effectively solve the problem of the drain voltage rising after the MOSFET is turned on, leading to a smaller voltage difference between the gate and drain. It also addresses the potential for conduction of the upper and lower bridge arms in the active equalization switch array within the equalization circuit switching module. The structure of the drive circuit is as follows: Figure 7 As shown, HIN and LIN are input interfaces connected to the main control unit, and OUT is the output interface connected to the gate of the driven MOSFET. Each MOSFET in the equalization circuit switch is connected to a driver circuit module. The power supply module supplies power to the MOSFETs in the equalization circuit switch module. Figure 6As shown, the balancing circuit switching module includes an active balancing unit and a passive balancing unit. The active and passive balancing units are connected to each individual cell within the battery pack. Q1-Q19 are MOSFETs; R1-R30 are resistors; C1-C12 are capacitors; BT1-BT6 are individual battery cells; D1-D6 are diodes; F1-F6 are control switches; and DC is the circuit power supply. The left side of the battery pack contains the active balancing unit, and the right side contains the passive balancing unit. The active balancing unit, or active balancing circuit, uses flying capacitors as energy storage elements and distributes them centrally. That is, each individual cell within the same battery pack shares a single flying capacitor for energy storage. A switching array is built using multiple metal-oxide-semiconductor field-effect transistors (MOS) to control the on / off state of the circuit between each individual cell and the flying capacitor, thereby achieving precise control and transferring energy from higher-capacity cells to lower-capacity cells. The passive balancing unit, or passive balancing circuit, consists of a load resistor connected in parallel across each individual cell in the battery pack to dissipate excess charge. A metal-oxide-semiconductor field-effect transistor (MOS) is connected in series in the loop to control the on / off state of the passive balancing circuit, thereby reducing the energy of higher-capacity cells. Two parallel resistors are connected to increase the overcurrent capacity of the passive balancing circuit loop. A display circuit can also be added to the passive balancing circuit, with an LED added to the circuit, allowing real-time monitoring of the passive balancing status through light flashing. The main control unit contains a control chip. This control chip, based on the SOC and SOH values of each individual cell in the battery pack received from the computing module, and in conjunction with the active and passive balancing strategy, generates balancing control commands for each individual cell in the battery pack. These commands include balancing commands or shielding commands (activation / deactivation commands, indicating whether a cell is put into or taken out of use), and are sent to the drive circuit module. Active and passive balancing strategies (such as...) Figure 8 As shown, this refers to comparing the real-time received SOC value of each individual cell in the battery pack with its initial SOC value. Based on the threshold range of the difference, a corresponding balancing command is generated. If the difference is greater than 5%, active balancing is initiated; if the difference is less than 5% but greater than 1%, passive balancing is activated; and if the difference is less than 1%, balancing is stopped. Even after active balancing is initiated, the system will still continuously check if the difference is less than 5%. When the difference reaches the threshold of less than 5% but greater than 1%, passive balancing is switched to active balancing; when the difference reaches less than 1%, balancing is stopped. The control chip of the drive circuit module is used to control the switching of MOS transistors in the active balancing unit's switch array or the passive balancing unit based on the received commands from the main control unit, thereby performing balancing control on each individual cell in the battery pack.
[0065] The equalization module also includes a control unit for enabling and disabling individual cells within the battery pack. A control switch is added to the circuit corresponding to the equalization module to control the enabling and disabling of each individual cell in the battery pack. The control switch is connected in series between the individual cell and the equalization module.
[0066] The computing module also calculates the state of charge (SOC) and health status of each individual cell in the battery pack based on the received monitoring data. It compares the SOC of a single cell with the average SOC of all cells and analyzes cells (or cells) below the average. If removing such a cell would improve the overall system capacity, the microcontroller unit of the computing module sends a removal command to the main control unit of the equalization module. The main control unit of the equalization module then controls the activation / deactivation unit to open the control switch, removing the cell from the series circuit. Simultaneously, the bypass switch is closed to ensure that other cells in the series circuit can operate normally. If the SOC of a single cell (or multiple cells) is below 70%, even if the SOC appears normal, it must be forcibly removed. After the single cell (or multiple cells) is removed, the entire system is re-analyzed and equalized, enabling battery system reconfiguration and early fault diagnosis and handling.
[0067] The system provided in this application also includes a charge / discharge control module, which is connected in series in the battery pack's charge / discharge circuit and is used to manage charge and discharge according to the instructions of the computing module. The charge / discharge control module is connected in series in the entire battery pack charge / discharge circuit and is used to control the charge and discharge of the battery pack according to the instructions of the computing module. In case of abnormal conditions (such as abnormal temperature, abnormal current, abnormal voltage, etc.), the circuit is quickly cut off according to the instructions of the computing module.
[0068] Based on the same concept as the aforementioned energy storage battery charge-discharge equalization control system, this application also provides an energy storage battery charge-discharge equalization control method, such as... Figure 9 As shown, it includes:
[0069] S101. The acquisition module acquires monitoring data of each individual cell in the battery pack and transmits the monitoring data to the computing module.
[0070] S102. The calculation module calculates the battery status of each individual cell in the battery pack based on the received monitoring data, and transmits the battery status of each individual cell in the battery pack to the equalization module.
[0071] S103. The balancing module performs balancing control on each individual cell in the battery pack based on the received battery state of each cell in the battery pack and the active and passive balancing strategy.
[0072] Furthermore, based on the received monitoring data, the computing module calculates the battery state of each individual cell within the battery pack, including:
[0073] Based on the received monitoring data, the calculation module uses a battery state-of-charge estimation method that combines different weights of the ampere-hour integration method, the Kalman filter method, and the open-circuit voltage method to calculate the state of charge and health status of each individual cell in the battery pack.
[0074] Furthermore, the balancing module, based on the received battery state of each individual cell within the battery pack and combined with active and passive balancing strategies, performs balancing control on each individual cell within the battery pack, including:
[0075] The main control unit of the equalization module generates equalization control commands for each individual cell in the battery pack based on the received battery status of each cell in the battery pack and the active and passive equalization strategies, and sends the commands to the drive circuit module of the equalization module.
[0076] The driving circuit module of the equalization module performs equalization control on each individual cell in the battery pack based on the equalization control command of each individual cell in the battery pack.
[0077] Furthermore, the main control unit of the equalization module generates equalization control commands for each individual cell in the battery pack based on the received battery state of each cell and the active / passive equalization strategy, including:
[0078] The main control unit of the equalization module compares the state of charge (SOC) values of each individual cell in the battery pack with the initial SOC value of each cell. Based on the range of the difference threshold, it generates a corresponding equalization command. If the difference is greater than 5%, active equalization is initiated; if the difference is less than 5% but greater than 1%, passive equalization is initiated; if the difference is less than 1%, equalization is stopped. After active equalization is initiated, the system will also continuously check whether the difference is less than 5%. When the difference reaches the threshold of less than 5% but greater than 1%, it switches to passive equalization; when the difference reaches less than 1%, it switches to stop equalization.
[0079] Furthermore, the driving circuit module of the balancing module performs balancing control on each individual cell within the battery pack based on balancing control commands, including:
[0080] The driving circuit module of the equalization module controls the switching of metal-oxide-semiconductor field-effect transistors in the active equalization unit or the passive equalization unit in the equalization circuit switching module of the equalization module, based on the equalization control command of each individual cell in the battery pack.
[0081] Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.
Claims
1. A system for maximizing the utilization of an energy storage battery, characterized in that, include: The data acquisition module is used to collect monitoring data of each individual cell in the battery pack and transmit the monitoring data to the computing module. The calculation module is used to calculate the battery state of each individual cell in the battery pack based on the received monitoring data, and transmit the battery state of each individual cell in the battery pack to the equalization module. The balancing module is also used to perform balancing control on each individual cell in the battery pack based on the received battery state of each individual cell in the battery pack and in combination with active and passive balancing strategies.
2. The energy storage battery maximum utilization system according to claim 1, characterized in that, The acquisition module further includes: a voltage acquisition unit, a current acquisition unit, and a temperature acquisition unit; The voltage acquisition unit connects the multi-cell detection chip that acquires the voltage of the circuit to each individual cell in the battery pack. An RC low-pass decoupling filter and a grounding filter capacitor are added to each input port of the multi-cell detection chip to acquire the voltage data of each individual cell in the battery pack and transmit the acquired voltage data to the computing module. In the current acquisition unit, a high-precision current shunt detection chip for acquiring circuit current is connected to each individual cell in the battery pack, and a voltage reference chip is connected to the pin of the high-precision current shunt detection chip to acquire the current data of each individual cell in the battery pack and transmit the acquired current data to the computing module. The temperature acquisition unit uses temperature sensors to sense the temperature of each individual cell in the battery pack in real time, collects temperature data of each individual cell in the battery pack, and transmits the collected temperature data to the computing module.
3. The energy storage battery maximum utilization system according to claim 1, characterized in that, The calculation module is also used to calculate the state of charge and health status of each individual cell in the battery pack based on the received monitoring data, using a battery state of charge estimation method that combines different weights of the ampere-hour integration method, the Kalman filtering method, and the open-circuit voltage method, and then transmit the results to the equalization module.
4. The energy storage battery maximum utilization system according to claim 1, characterized in that, The equalization module also includes: an equalization circuit switch module, a main control unit, and a drive circuit module; The equalization circuit switching module includes an active equalization unit and a passive equalization unit. The active equalization unit is used to control the circuit switching between each individual cell in the battery pack and the common flying capacitor through a switching array built with multiple metal-oxide-semiconductor field-effect transistors, transferring energy from the individual cells with higher capacity to the individual cells with lower capacity. The passive equalization unit is used to control the switching of the load resistor connected in parallel across each individual cell in the battery pack through metal-oxide-semiconductor field-effect transistors, reducing the energy of the individual cells with higher capacity. The main control unit is used to generate equalization control commands for each individual cell in the battery pack based on the received battery state of each individual cell in the battery pack and the active and passive equalization strategy, and send the commands to the drive circuit module; it is also used to execute the operation module to issue exit commands based on the state of charge and health of each individual cell in the battery pack. The drive circuit module is used to drive and control the metal-oxide-semiconductor field-effect transistors in the equalization circuit switching module through the drive chip, based on the equalization control commands of the main control unit.
5. The energy storage battery maximum utilization system according to claim 4, characterized in that, The main control unit is also used for: The system compares the state of charge (SOC) values of each individual cell in the battery pack with the initial SOC values of each cell. Based on the range of the difference threshold, it generates corresponding balancing commands. If the difference is greater than 5%, active balancing is initiated; if the difference is less than 5% but greater than 1%, passive balancing is initiated; if the difference is less than 1%, balancing is stopped. After active balancing is initiated, the system will also continuously check whether the difference is less than 5%. When the difference reaches the threshold of less than 5% but greater than 1%, it switches to passive balancing; when the difference reaches less than 1%, it switches to stopping balancing.
6. A method for maximizing the utilization of an energy storage battery, characterized in that, include: The acquisition module collects monitoring data from each individual cell in the battery pack and transmits the monitoring data to the charging equalization module; The equalization module transmits the received monitoring data to the calculation module; Based on the received monitoring data, the calculation module calculates the battery state of each individual cell in the battery pack and transmits the battery state of each individual cell in the battery pack to the equalization module. The balancing module performs balancing control on each individual cell in the battery pack based on the received battery state of each cell and the active and passive balancing strategy.
7. The method for maximizing the utilization of an energy storage battery according to claim 6, characterized in that, Based on the received monitoring data, the calculation module calculates the battery state of each individual cell in the battery pack, including: Based on the received monitoring data, the calculation module uses a battery state-of-charge estimation method that combines different weights of the ampere-hour integral method, the Kalman filter method, and the open-circuit voltage method to calculate the state of charge and health status of each individual cell in the battery pack.
8. The method for maximizing the utilization of an energy storage battery according to claim 6, characterized in that, The equalization module performs equalization control on each individual cell in the battery pack based on the received battery state and a combination of active and passive equalization strategies, including: The main control unit of the equalization module generates equalization control commands for each individual cell in the battery pack based on the received battery status of each cell in the battery pack and the active and passive equalization strategies, and sends the commands to the drive circuit module of the equalization module. The driving circuit module of the equalization module performs equalization control on each individual cell in the battery pack based on the equalization control command of each individual cell in the battery pack.
9. The method for maximizing the utilization of an energy storage battery according to claim 8, characterized in that, The main control unit of the equalization module generates equalization control commands for each individual cell in the battery pack based on the received battery state of each cell and the active / passive equalization strategy, including: The main control unit of the equalization module will compare the state of charge (SOC) values of each individual cell in the battery pack with the initial SOC values of each individual cell. Based on the range of the difference threshold, a corresponding equalization command will be generated. If the difference is greater than 5%, active equalization will be started; if the difference is less than 5% but greater than 1%, passive equalization will be started; if the difference is less than 1%, equalization will be stopped. After active equalization is started, the system will also judge in real time whether the difference is less than 5%. When the difference reaches the threshold of less than 5% but greater than 1%, it will switch to passive equalization. When the difference reaches less than 1%, it will switch to stop equalization.
10. The method for maximizing the utilization of an energy storage battery according to claim 8, characterized in that, The driving circuit module of the equalization module performs equalization control on each individual cell in the battery pack based on equalization control commands, including: The driving circuit module of the equalization module controls the switching of metal-oxide-semiconductor field-effect transistors in the active equalization unit or the passive equalization unit in the equalization circuit switching module of the equalization module, based on the equalization control command of each individual cell in the battery pack.