Method for realizing parallel switching of battery clusters through automatic cluster switching and automatic cluster throwing

Abstract

The invention discloses a method for realizing parallel switching of battery clusters through automatic cluster switching and automatic cluster switching, which comprises the following steps of: adding cluster contactors: on a direct current side of an energy storage system, when a plurality of clusters are connected in parallel, adding the cluster contactors as a control unit, and reducing direct current circulating current loss among the clusters; when the energy storage system is about to complete charging, a high-voltage cluster is cut, and a low-voltage cluster is continuously charged; when the discharge of the energy storage system is about to be finished, the low voltage cluster is switched, and the high voltage cluster is continuously discharged; performing cluster floating charge management; detecting the voltage of each cluster after charging or discharging is finished; the method has the beneficial effects that the problems in the prior art are effectively solved by additionally arranging the cluster contactor, formulating a BMS cluster cutting and cluster throwing strategy and performing cluster floating charge management, the efficiency of the energy storage system and the consistency of the battery cells are improved, the dispersion of the voltage of the battery cells is reduced, and the method has remarkable technical progress and practical application value.

Description

Technical Field

[0001] The invention belongs to the technical field of parallel switching of battery clusters, and in particular relates to a method for realizing parallel switching of battery clusters through automatic cluster cutting and automatic cluster switching. Background Art

[0002] A battery cluster refers to a battery module composed of several battery cells; it is an independent unit, usually referring to a single lithium-ion battery or other type of rechargeable battery; in electrical design, a battery cluster requires a series of protection components to control its normal disconnection, overcurrent protection, overvoltage, undervoltage protection and short circuit protection; the characteristics of a battery cluster are that it can provide higher voltage and capacity to meet higher power requirements; compared with a single battery cell, the capacity, voltage and operating temperature range of a battery cluster will be more stable; these battery cells are connected together through connectors to provide higher voltage and capacity.

[0003] The patent number is CN115864603A, which discloses a battery cluster parallel switching method, including a contactor / control circuit breaker, BPU: battery PACK unit acquisition controller, BKU: battery cluster parallel unit acquisition controller, BMU: energy storage centralized control system, PACK: battery stack unit, PCS: energy storage converter; an acquisition unit, the acquisition unit is respectively connected to the energy storage centralized control system and PCS for communication, and the battery data and PCS data during charging and discharging of the energy storage centralized control system are collected through the acquisition unit; a processing unit, the processing unit is connected to the acquisition unit for communication, and the processing unit processes the acquisition unit The data collected by the data acquisition unit are summarized and analyzed; the battery cluster parallel unit acquisition controller and the processing unit are communicated and connected, and the parallel battery cluster is controlled by the battery cluster parallel unit acquisition controller for switching control; the PACK and BPU are communicated and connected; the contactor / control circuit breaker is connected in series to the battery cluster; the switching method is as follows: step one: the battery data and PCS data during charging and discharging of the energy storage centralized control system are collected by the acquisition unit; step two: the data collected by the acquisition unit are summarized and analyzed by the processing unit; step three: the parallel battery cluster is controlled by the battery cluster parallel unit acquisition controller for switching control.

[0004] Although the patent with publication number CN115864603A realizes the switching control of battery clusters through acquisition units, processing units and battery cluster parallel unit acquisition controllers, there are still problems such as inter-cluster DC circulation loss, high battery cell consistency requirements and large battery cell voltage dispersion in actual applications. Summary of the invention

[0005] The object of the present invention is to provide a method for realizing parallel switching of battery clusters through automatic cluster switching and automatic cluster switching, thereby improving the efficiency of the energy storage system and the consistency of the battery cells and reducing the discreteness of the battery cell voltage.

[0006] To achieve the above object, the present invention provides the following technical solution: a method for realizing parallel switching of battery clusters by automatic cluster switching and automatic cluster switching, comprising the following steps:

[0007] Install cluster contactors: On the DC side of the energy storage system, when multiple clusters are connected in parallel, install cluster contactors as control units to reduce DC circulation losses between clusters;

[0008] Formulate BMS cluster cutting and clustering strategies: When the energy storage system is about to be fully charged, the high-voltage cluster is cut and the low-voltage cluster is continued to be charged; when the energy storage system is about to be fully discharged, the low-voltage cluster is cut and the high-voltage cluster is continued to be discharged;

[0009] Perform cluster floating charge management: detect the voltage of each cluster after charging or discharging; calculate the replenishment value of each battery cell based on the big data analysis function; and perform floating charge on the battery cells in sequence until the cluster cutting and cluster adding strategies are met.

[0010] As a preferred technical solution of the present invention, on the DC side of the energy storage system, when multiple clusters are connected in parallel, a cluster contactor is installed as a control unit. The corresponding contents are as follows:

[0011] Conduct detailed analysis on the DC side of the energy storage system to understand the number, voltage level, and current demand parameters of the battery clusters; design cluster contactor control solutions based on system requirements;

[0012] Select contactors suitable for the voltage and current levels of the DC side of the energy storage system; consider the breaking capacity, contact resistance, and operating frequency indicators of the contactors; prepare the required number of cluster contactors, mounting brackets, connecting cables, insulating materials, and fasteners;

[0013] Determine the installation position of each cluster contactor according to the system design; use the mounting bracket to fix the cluster contactor at the predetermined position; use well-insulated connecting cables to connect the input end of the cluster contactor to the positive and negative poles of the battery cluster, and the output end to the DC bus; after the installation is completed, carefully check whether all connections are firm and reliable, and ensure that there are no exposed wires or poor contact; ensure that the contactor can be closed and opened normally when powered on, and that all electrical parameters meet the design requirements;

[0014] Connect the control signal line of the cluster contactor to the control system of the energy storage system to ensure that the control signal can be accurately and reliably transmitted to the contactor; write the corresponding control program according to the operation requirements of the energy storage system; ensure that the voltage and current parameters of the battery cluster can be monitored in real time during the parallel process, and adjust the control strategy according to the actual situation;

[0015] Before actual operation, the control program is debugged and verified; the correctness and reliability of the control program are checked by simulating the parallel process under various working conditions; and it is ensured that when an abnormal situation occurs, the control system can cut off the contactor in time to protect the safety of the battery cluster and the entire energy storage system.

[0016] As a preferred technical solution of the present invention, a cluster contactor control solution is designed, including the selection, layout and control logic of the contactor.

[0017] As a preferred technical solution of the present invention, the voltage of each cluster after charging or discharging is detected, including direct measurement method and indirect measurement method.

[0018] As a preferred technical solution of the present invention, the power replenishment value of each battery cell is calculated based on the big data analysis function, and the corresponding content is as follows:

[0019] The voltage, current and temperature parameters of each battery cell are monitored in real time through the battery management system;

[0020] Collect historical charge and discharge data of the battery cells;

[0021] Remove outliers and duplicate data; convert raw data into a format suitable for analysis; extract useful features from preprocessed data;

[0022] Use machine learning algorithms to identify the charging and discharging modes of battery cells, as well as their performance under different modes; use predictive models based on historical data to predict future performance trends of battery cells;

[0023] According to the data analysis results, set the threshold for the battery cells to be recharged; prioritize the battery cells that need to be recharged according to their performance status and importance; calculate the amount of electricity that needs to be replenished according to the current status and performance trend of the battery cells; formulate a specific recharge plan based on the recharge strategy; execute the recharge operation according to the plan, and monitor the status of the battery cells during the recharge process;

[0024] After the charging is completed, the charging effect is evaluated; the charging effect is fed back to the data analysis link to optimize the charging strategy and model; the battery cell status is continuously monitored, and the charging strategy is adjusted in time to adapt to changes in battery cell performance.

[0025] As a preferred technical solution of the present invention, historical charge and discharge data of the battery cells are collected, including charge and discharge times and capacity attenuation.

[0026] As a preferred technical solution of the present invention, useful features extracted include voltage change rate and capacity decay rate.

[0027] As a preferred technical solution of the present invention, the power replenishment plan includes power replenishment time and power replenishment amount.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] By adding cluster contactors, formulating BMS cluster cutting and cluster adding strategies, and performing cluster floating charge management, the problems existing in the existing technology are effectively solved, the efficiency of the energy storage system and the consistency of the battery cells are improved, and the discreteness of the battery cell voltage is reduced, which has significant technological progress and practical application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a flow chart of the switching method of the present invention. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Example 1

[0033] See also Figure 1 , which is the first embodiment of the present invention, provides a method for implementing parallel switching of battery clusters through automatic cluster switching and automatic cluster switching, comprising the following steps:

[0034] Install cluster contactors: On the DC side of the energy storage system, when multiple clusters are connected in parallel, install cluster contactors as control units to reduce DC circulation losses between clusters;

[0035] Formulate BMS cluster cutting and clustering strategies: When the energy storage system is about to be fully charged, the high-voltage cluster is cut and the low-voltage cluster is continued to be charged; when the energy storage system is about to be fully discharged, the low-voltage cluster is cut and the high-voltage cluster is continued to be discharged;

[0036] Perform cluster floating charge management: detect the voltage of each cluster after charging or discharging; calculate the replenishment value of each battery cell based on the big data analysis function; and perform floating charge on the battery cells in sequence until the cluster cutting and cluster adding strategies are met.

[0037] In this embodiment, preferably, on the DC side of the energy storage system, when multiple clusters are connected in parallel, a cluster contactor is installed as a control unit, and the corresponding contents are as follows:

[0038] Conduct detailed analysis of the DC side of the energy storage system to understand key parameters such as the number of battery clusters, voltage level, and current requirements;

[0039] Design a reasonable cluster contactor control solution according to system requirements, including contactor selection, layout location, control logic, etc.;

[0040] Select contactors suitable for the voltage and current levels of the DC side of the energy storage system; consider key indicators such as the contactor's breaking capacity, contact resistance, and operating frequency; prepare the required number of cluster contactors, mounting brackets, connecting cables, insulating materials, fasteners, etc.;

[0041] Determine the installation position of each cluster contactor according to the system design; use the mounting bracket to fix the cluster contactor in the predetermined position to ensure that the contactor is firmly installed and the wiring terminals are easy to connect;

[0042] Use well-insulated connecting cables to connect the input end of the cluster contactor to the positive and negative poles of the battery cluster, and the output end to the DC bus;

[0043] After installation, carefully check whether all connections are firm and reliable, without exposed wires or poor contact; perform electrical tests to ensure that the contactor can close and open normally when powered on, and that all electrical parameters meet the design requirements;

[0044] Connect the control signal line of the cluster contactor to the control system of the energy storage system to ensure that the control signal can be accurately and reliably transmitted to the contactor;

[0045] According to the operation requirements of the energy storage system, write the corresponding control program, which should include the parallel control logic and safety protection logic of the battery cluster; ensure that the voltage, current and other parameters of the battery cluster can be monitored in real time during the parallel process, and adjust the control strategy according to the actual situation;

[0046] Before actual operation, the control program is debugged and verified. By simulating the parallel process under various working conditions, the correctness and reliability of the control program are checked to ensure that when abnormal situations occur (such as abnormal battery cluster voltage, excessive current, etc.), the control system can cut off the contactor in time to protect the safety of the battery cluster and the entire energy storage system.

[0047] In this embodiment, preferably, the power replenishment value of each battery cell is calculated based on the big data analysis function, and the corresponding content is as follows:

[0048] The voltage, current and temperature parameters of each battery cell are monitored in real time through the battery management system;

[0049] Collect historical charge and discharge data of the battery cell, including the number of charge and discharge times and capacity attenuation;

[0050] Remove outliers and duplicate data; convert raw data into a format suitable for analysis; extract useful features from preprocessed data, including voltage change rate and capacity attenuation rate;

[0051] Use machine learning algorithms to identify the charging and discharging modes of battery cells, as well as their performance under different modes; use predictive models based on historical data to predict future performance trends of battery cells;

[0052] According to the data analysis results, set the threshold for the battery cells to be recharged; prioritize the battery cells that need to be recharged according to their performance status and importance; calculate the amount of electricity that needs to be recharged based on the current status and performance trend of the battery cells; formulate a specific recharge plan based on the recharge strategy, which includes the recharge time and recharge amount; execute the recharge operation according to the plan, and monitor the battery cell status during the recharge process;

[0053] After the charging is completed, the charging effect is evaluated; the charging effect is fed back to the data analysis link to optimize the charging strategy and model; the battery cell status is continuously monitored, and the charging strategy is adjusted in time to adapt to changes in battery cell performance.

[0054] Example 2

[0055] See also Figure 1 , which is the second embodiment of the present invention, is based on the previous embodiment, except that:

[0056] Detecting the voltage of each cluster after charging or discharging, including direct measurement method and indirect measurement method;

[0057] Direct measurement method: It is the most direct and commonly used voltage detection method. This method uses a high-precision voltmeter or data acquisition system to directly connect to the positive and negative electrodes of the battery cluster to measure its open circuit voltage or working voltage. The implementation steps are as follows:

[0058] Prepare tools: Select a high-precision voltmeter or data acquisition system suitable for the battery cluster voltage range;

[0059] Connection measurement: Connect the positive and negative poles of the voltmeter to the positive and negative poles of the battery cluster respectively, ensuring that the connection is firm and the contact is good;

[0060] Read data: Start the voltmeter or data acquisition system to read and record the voltage value of the battery cluster;

[0061] Data analysis: Analyze the status of the battery cluster based on the read voltage value to determine whether further processing is required.

[0062] Indirect measurement method: indirectly obtain the voltage information of the battery cluster by measuring the output signal of the battery management system; the implementation steps are as follows:

[0063] BMS interface connection: connect the data acquisition system or test equipment to the communication interface of the BMS;

[0064] Data request: Send voltage data request instructions to BMS through the communication protocol;

[0065] Data reception and analysis: Receive voltage data returned by BMS, and parse and analyze it.

[0066] Although the embodiments of the present invention have been shown and described, as detailed above, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for realizing parallel switching of battery clusters by automatic cluster switching and automatic cluster switching, characterized in that: The steps include: Install cluster contactors: On the DC side of the energy storage system, when multiple clusters are connected in parallel, install cluster contactors as control units to reduce DC circulation losses between clusters; Formulate BMS cluster cutting and clustering strategies: When the energy storage system is about to be fully charged, the high-voltage cluster is cut and the low-voltage cluster is continued to be charged; when the energy storage system is about to be fully discharged, the low-voltage cluster is cut and the high-voltage cluster is continued to be discharged; Perform cluster floating charge management: detect the voltage of each cluster after charging or discharging; calculate the replenishment value of each battery cell based on the big data analysis function; and perform floating charge on the battery cells in sequence until the cluster cutting and cluster adding strategies are met.

2. A method for realizing parallel switching of battery clusters by automatic cluster switching and automatic cluster switching according to claim 1, characterized in that: On the DC side of the energy storage system, when multiple clusters are connected in parallel, the corresponding contents of installing a cluster contactor as a control unit are as follows: Conduct detailed analysis on the DC side of the energy storage system to understand the number, voltage level, and current demand parameters of the battery clusters; design cluster contactor control solutions based on system requirements; Select a contactor suitable for the DC side voltage and current level of the energy storage system; Consider the breaking capacity, contact resistance, and operating frequency indicators of the contactor; prepare the required number of cluster contactors, mounting brackets, connecting cables, insulating materials, and fasteners; Determine the installation location of each cluster contactor according to the system design; Use the mounting bracket to fix the cluster contactor in the predetermined position; use a well-insulated connecting cable to connect the input end of the cluster contactor to the positive and negative electrodes of the battery cluster, and the output end to the DC bus; After installation, carefully check whether all connections are firm and reliable, and ensure that there are no exposed wires or poor contact; Ensure that the contactor can close and open normally when powered on, and that all electrical parameters meet the design requirements; Connect the control signal line of the cluster contactor to the control system of the energy storage system to ensure that the control signal can be accurately and reliably transmitted to the contactor; write the corresponding control program according to the operation requirements of the energy storage system; ensure that the voltage and current parameters of the battery cluster can be monitored in real time during the parallel process, and adjust the control strategy according to the actual situation; Before actual operation, debug and verify the control program; check the correctness and reliability of the control program by simulating the parallel process under various working conditions; Ensure that when an abnormal situation occurs, the control system can cut off the contactor in time to protect the safety of the battery cluster and the entire energy storage system.

3. The method for realizing parallel switching of battery clusters by automatic cluster switching and automatic cluster switching according to claim 2, characterized in that: Design cluster contactor control scheme, including contactor selection, layout location, and control logic.

4. The method for realizing parallel switching of battery clusters by automatic cluster switching and automatic cluster switching according to claim 1, characterized in that: The voltage of each cluster after charging or discharging is detected, including direct measurement method and indirect measurement method.

5. The method for realizing parallel switching of battery clusters by automatic cluster switching and automatic cluster switching according to claim 1, characterized in that: Based on the big data analysis function, the charging value of each battery cell is calculated, and the corresponding content is as follows: The voltage, current and temperature parameters of each battery cell are monitored in real time through the battery management system; Collect historical charge and discharge data of the battery cells; Remove outliers and duplicate data; convert raw data into a format suitable for analysis; extract useful features from preprocessed data; Use machine learning algorithms to identify the charging and discharging modes of the battery cells, as well as their performance under different modes; Based on historical data, use prediction models to predict future performance trends of battery cells; According to the data analysis results, set the threshold for the battery cells to be recharged; prioritize the battery cells that need to be recharged according to their performance status and importance; calculate the amount of electricity that needs to be replenished according to the current status and performance trend of the battery cells; formulate a specific recharge plan based on the recharge strategy; execute the recharge operation according to the plan, and monitor the status of the battery cells during the recharge process; After the charging is completed, the charging effect is evaluated; the charging effect is fed back to the data analysis link to optimize the charging strategy and model; the battery cell status is continuously monitored, and the charging strategy is adjusted in time to adapt to changes in battery cell performance.

6. The method for realizing parallel switching of battery clusters by automatic cluster switching and automatic cluster switching according to claim 5, characterized in that: Collect historical charge and discharge data of the battery cell, including the number of charge and discharge times and capacity attenuation.

7. The method for realizing parallel switching of battery clusters by automatic cluster switching and automatic cluster switching according to claim 5, characterized in that: The extracted useful features include voltage change rate and capacity decay rate.

8. The method for realizing parallel switching of battery clusters by automatic cluster switching and automatic cluster switching according to claim 5, characterized in that: The power replenishment plan includes the power replenishment time and power replenishment amount.

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