Battery liquid leakage detection method applied to energy storage system

Abstract

The invention discloses a battery liquid leakage detection method applied to an energy storage system, and the method comprises the following steps: S1, gas detection: detecting gas in the energy storage system through a gas detection module, and uploading gas parameter data to a master controller; s2, insulation detection: detecting an insulation resistance value of the system in real time through an insulation detection module, and judging whether resistance value data is normal or not in real time; and S3, internal resistance detection: detecting the internal resistance and the internal resistance value of the battery cell through an internal resistance detection module. According to the invention, gas detection, voltage detection and resistance detection are carried out on the leakage battery, and the state of the battery is detected in the system operation process, so that three-level protection on the system is realized, the safety of the battery in operation is ensured, the safety of the system is improved, the function of the system is expanded, and the system has the advantages of automation, low cost and the like. The battery fault can be quickly diagnosed, the working efficiency of system maintenance is greatly improved, and the maintenance cost of the system is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of energy storage batteries, and in particular relates to a battery leakage detection method applied to an energy storage system. Background Art

[0002] Lithium-ion batteries have the advantages of high operating voltage, high energy density and long cycle life. They are increasingly used as energy storage carriers. They are not only widely used in various electronic consumer products, but are also widely used in electric vehicles, electrochemical energy storage and other fields.

[0003] In energy storage systems, especially large energy storage systems, batteries may be damaged or leak due to various reasons during transportation or use. Such situations are very dangerous, so rapid diagnosis and troubleshooting are required in the system. Patent document CN204649362U records a zinc-bromine liquid flow energy storage battery leakage detection system, but this method can only be detected after a certain amount of electrolyte has leaked, and further detection of battery pack leakage cannot be performed. Instead, the entire pack is detected inside the high-voltage box. If the battery cluster is judged to be faulty, the entire machine needs to be stopped, which greatly reduces the working efficiency of the system. Summary of the invention

[0004] In view of the problems raised by the above background technology, the purpose of the present invention is to provide a battery leakage detection method applied to an energy storage system.

[0005] In order to achieve the above technical objectives, the technical solution adopted by the present invention is as follows:

[0006] A battery leakage detection method applied to an energy storage system comprises the following steps:

[0007] S1: Gas detection: detect the gas inside the energy storage system through the gas detection module and upload the gas parameter data to the main control;

[0008] S2: Insulation detection, the insulation resistance value of the system is detected in real time through the insulation detection module, and the resistance value data is judged in real time whether it is normal;

[0009] S3: Internal resistance detection, detect the internal resistance and internal resistance value of the battery cell through the internal resistance detection module.

[0010] It is further defined that in said S1, the gas detection module includes a gas detection sensor and its peripheral circuits, wherein the gas detection sensor is used to collect data, and when the gas detection module receives a communication instruction from the main control, it starts to detect gas parameters and returns the detected parameters to the main control.

[0011] It is further defined that in S1, if there is no abnormality in the gas parameters and the insulation resistance of the detection system, such as the insulation resistance detection of the battery pack, is normal, it is judged that the battery collection is faulty; if there is no abnormality in the gas but the insulation resistance collection is abnormal, it is judged that there is no abnormality in the battery information.

[0012] It is further defined that in S2, the insulation detection module includes a control switch, a sampling resistor and its peripheral circuits. There are two voltages at the two ends of the power bus, the positive terminal voltage and the negative terminal voltage. When performing insulation detection, the voltage is sampled twice through AD sampling, and the actual insulation resistance is calculated based on the parallel resistance value and the positive and negative voltage values.

[0013] It is further defined that in S2, the calculated resistance value needs to be compared with the corresponding voltage-resistance table, and the table value is compared with the actual value. If the difference is within the allowable range, the detection is normal. If the difference is too large, the insulation detection is abnormal.

[0014] It is further defined that in said S3, the internal resistance detection module includes a control unit and a detection unit, wherein the control unit is used to control the switching of the connected battery cells to facilitate the collection of resistance, and the detection unit is used to detect the internal resistance of the battery cells.

[0015] It is further defined that in S3, when the insulation detects leakage in the battery pack, the positive control switch of the battery pack is first disconnected, and then the internal resistance detection module is connected to the faulty battery pack. After power-on, the voltage of each battery cell is detected on the BMU, and the internal resistance value of the battery cell is estimated by looking up the table. If the internal resistance value is too large or too low, the battery cell is abnormal, and the serial number of the battery cell is uploaded through the communication module.

[0016] The beneficial effects of the present invention are as follows: the present invention uses a three-layer detection module, a gas detection module for detecting the gas of a leaking battery pack, an insulation detection module between the outer shell and the battery, and an internal resistance detection module. The present invention detects the gas, voltage and resistance of the leaking battery, and is integrated into the system according to the physical characteristics of the leaking battery. The battery status is detected during the operation of the system, thereby achieving three-level protection for the system, ensuring the safety of the running battery, improving the safety of the system, and expanding the functions of the system. The present invention has the characteristics of automation and rapid diagnosis of battery failures, which greatly improves the work efficiency of system maintenance and reduces the maintenance cost of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention can be further illustrated by the non-limiting examples given in the accompanying drawings;

[0018] Figure 1 A schematic diagram of the structure of a detection process of a battery leakage detection method applied to an energy storage system according to an embodiment of the present invention;

[0019] Figure 2 A schematic diagram of the connection structure of a battery leakage detection method applied to an energy storage system according to an embodiment of the present invention;

[0020] Figure 3 A schematic diagram of a leakage detection structure of a BCU in a battery leakage detection method applied to an energy storage system according to an embodiment of the present invention;

[0021] Figure 4 A schematic diagram of a leakage detection structure of a BMU in a battery leakage detection method applied to an energy storage system according to an embodiment of the present invention; DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the present invention, the technical solution of the present invention is further described below in conjunction with embodiments.

[0023] like Figure 1-4 As shown, a battery leakage detection method applied to an energy storage system of the present invention comprises the following steps:

[0024] S1: Gas detection: detect the gas inside the energy storage system through the gas detection module and upload the gas parameter data to the main control;

[0025] S2: Insulation detection, the insulation resistance value of the system is detected in real time through the insulation detection module, and the resistance value data is judged in real time whether it is normal;

[0026] S3: Internal resistance detection, detect the internal resistance and internal resistance value of the battery cell through the internal resistance detection module.

[0027] Preferably, in S1, the gas detection module includes a gas detection sensor and its peripheral circuits, wherein the gas detection sensor is used to collect data, and when the gas detection module receives a communication instruction from the main control, it starts to detect gas parameters and returns the detected parameters to the main control.

[0028] Preferably, in S1, if there is no abnormality in the gas parameters and the insulation resistance of the detection system, such as the insulation resistance detection of the battery pack, is normal, it is determined that the battery collection is faulty; if there is no abnormality in the gas but there is an abnormality in the insulation resistance collection, it is determined that there is no abnormality in the battery information.

[0029] Preferably, in S2, the insulation detection module includes a control switch, a sampling resistor and its peripheral circuits. There are two voltages at the two ends of the power bus, the positive terminal voltage and the negative terminal voltage. When performing insulation detection, the voltage is sampled twice through AD sampling, and the actual insulation resistance is calculated based on the parallel resistance value and the positive and negative voltage values.

[0030] Preferably, in S2, the calculated resistance value needs to be compared with the corresponding voltage-resistance table, and the table value is compared with the actual value. If the difference is within the allowable range, the detection is normal. If the difference is too large, the insulation detection is abnormal.

[0031] Preferably, in S3, the internal resistance detection module includes a control unit and a detection unit, wherein the control unit is used to control the switching of the connected battery cells to facilitate the collection of resistance, and the detection unit is used to detect the internal resistance of the battery cells.

[0032] Preferably, in S3, when the insulation detects leakage in the battery pack, the positive control switch of the battery pack is first disconnected, and then the internal resistance detection module is connected to the faulty battery pack. After power-on, the voltage of each battery cell is detected on the BMU, and the internal resistance value of the battery cell is estimated by looking up the table. If the internal resistance value is too large or too low, the battery cell is abnormal, and the serial number of the battery cell is uploaded through the communication module.

[0033] In this embodiment, the battery voltage detection, gas detection, insulation detection and internal resistance detection are performed through three-level detection;

[0034] in,

[0035] The first level is through gas detection, which detects the gas inside the system through the gas detection module and uploads the gas parameters. The second level is through insulation detection, which compares the insulation resistance value obtained by BCU detection with the standard value. If the difference between the two values ​​is large, it is judged that the insulation detection has failed. The third level mainly detects the internal resistance of the battery cell and the internal resistance value.

[0036] The second level is through insulation detection. The gas detection module detects the gas parameters inside the closed system in real time when the system is running, and uploads it to the system center. According to the gas detection parameters, it is judged whether each battery cell in the system is in a normal state. When the gas detection parameters are abnormal, the insulation resistance detection is started. There is a positive terminal voltage and a negative terminal voltage at the positive and negative ends of the power supply side. First, turn on the control switch of the main negative end, the main control performs a voltage sampling, and obtains the voltage U1, then disconnects the control switch of the main negative end, turns on the control switch of the main positive end, and performs the battery voltage U2 again. At the same time, turn on the control switches of the main positive end and the main negative end. A resistor is connected to the main positive and negative ends of the circuit, and the resistors at both ends are connected to obtain two voltage values ​​U3 and U4. According to the calculation formula of the insulation resistance, a value is obtained, which is compared with the insulation resistance and the parameter table in the system. If the actual parameter and the actual value are outside the error range, the insulation detection fails, and the system reports a secondary alarm.

[0037] The third level is through internal resistance detection. First, the resistance detection unit groups the batteries in the pack and measures the voltage of each group to get the total voltage value of 2-4 groups. The voltage of each group is within a certain range. The highest and lowest two groups in a group are found. The main control is used to control the on and off of the control switch for these two groups. The specific judgment of the control switch is first based on the SOH estimated by the system. When the SOH value is larger than others, the internal resistance self-test control switch is turned on.

[0038] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A battery leakage detection method used in an energy storage system, characterized in that: The following steps are involved: S1: Gas detection: detect the gas inside the energy storage system through the gas detection module and upload the gas parameter data to the main control; S2: Insulation detection, the insulation resistance value of the system is detected in real time through the insulation detection module, and the resistance value data is judged in real time whether it is normal; S3: Internal resistance detection, detect the internal resistance and internal resistance value of the battery cell through the internal resistance detection module.

2. A battery leakage detection method for an energy storage system according to claim 1, characterized in that: In S1, the gas detection module includes a gas detection sensor and its peripheral circuits, wherein the gas detection sensor is used to collect data. When the gas detection module receives a communication instruction from the main control, it starts to detect gas parameters and returns the detected parameters to the main control.

3. A battery leakage detection method for use in an energy storage system according to claim 2, characterized in that: In S1, if there is no abnormality in the gas parameters and the insulation resistance of the detection system, such as the insulation resistance detection of the battery pack, is normal, it is determined that the battery collection is faulty; if there is no abnormality in the gas but the insulation resistance collection is abnormal, it is determined that there is no abnormality in the battery information.

4. The battery leakage detection method used in an energy storage system according to claim 1, characterized in that: In S2, the insulation detection module includes a control switch, a sampling resistor and its peripheral circuits. There are two voltages at the two ends of the power bus, the positive terminal voltage and the negative terminal voltage. When performing insulation detection, the voltage is sampled twice through AD sampling, and the actual insulation resistance is calculated based on the parallel resistance value and the positive and negative voltage values.

5. A battery leakage detection method used in an energy storage system according to claim 4, characterized in that: In S2, the calculated resistance value needs to be compared with the corresponding voltage-resistance table, and the table value is compared with the actual value. If the difference is within the allowable range, the detection is normal. If the difference is too large, the insulation detection is abnormal.

6. The battery leakage detection method used in an energy storage system according to claim 1, characterized in that: In the above S3, the internal resistance detection module includes a control unit and a detection unit, wherein the control unit is used to control the switching of the connected battery cells to facilitate the collection of resistance, and the detection unit is used to detect the internal resistance of the battery cells.

7. A battery leakage detection method used in an energy storage system according to claim 6, characterized in that: In S3, when the insulation detects leakage in the battery pack, the positive control switch of the battery pack is first disconnected, and then the internal resistance detection module is connected to the faulty battery pack. After power-on, the voltage of each battery cell is detected on the BMU, and the internal resistance value of the battery cell is estimated by looking up the table. If the internal resistance value is too large or too low, the battery cell is abnormal, and the serial number of the battery cell is uploaded through the communication module.

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