A safety monitoring system for electric vehicle power batteries

Abstract

This invention discloses a safety monitoring system for an electric vehicle's power battery, specifically comprising: a first detection module for continuously detecting whether a collision event has occurred in the electric vehicle; a second detection module for continuously detecting the insulation resistance value of the power battery; and a judgment module for comparing the real-time insulation resistance value of the power battery detected by the second detection module with a set insulation resistance threshold, and sending an insulation resistance value abnormality warning signal when the real-time insulation resistance value of the power battery is lower than the set insulation resistance threshold; when the control module receives a collision event signal from the first detection module, the control module, the second detection module, and the judgment module maintain low-voltage power supply; when the control module receives the insulation resistance value abnormality warning signal from the judgment module, it determines that the power battery has a risk of thermal runaway. This invention continuously detects the risk of battery thermal runaway even after a collision, improving battery safety after a collision.

Description

Technical Field

[0001] This invention relates to the field of battery thermal runaway monitoring technology, and in particular to a safety monitoring system for electric vehicle power batteries. Background Technology

[0002] With the rapid development of electric vehicles, the market is paying increasing attention to their safety. Developing the electric vehicle industry necessitates prioritizing the safety and reliability of power batteries. Battery cells can experience thermal runaway when subjected to overcharging, puncture, or impact, generating a large amount of heat. Without proper heat dissipation and other protective measures, the thermally runaway cell will rapidly transfer heat to surrounding cells, triggering a chain reaction of thermal runaway across numerous cells, potentially leading to battery pack fires or even explosions, seriously threatening personnel safety.

[0003] Current safety monitoring solutions for power batteries typically cut off the high voltage and disconnect the main negative and main positive contactors of the power battery directly after receiving a collision signal, and then directly power down the system. This lacks continuous safety monitoring of the power battery after a collision. When using this solution, if there is a short circuit in the acquisition harness inside the battery pack or a short circuit between the high voltage jumper and the battery casing, there will be a risk of thermal runaway, which will increase the risk of vehicle spontaneous combustion or electric shock to personnel. Summary of the Invention

[0004] In view of the above problems, the present invention provides a safety monitoring system for electric vehicle power batteries that overcomes or at least partially solves the above problems, the technical solution of which is as follows:

[0005] A safety monitoring system for electric vehicle power batteries, comprising:

[0006] The first detection module is used to continuously detect whether a collision event has occurred with the electric vehicle.

[0007] The second detection module is used to continuously detect the insulation resistance value of the power battery;

[0008] The judgment module communicates with the second detection module, compares the real-time insulation resistance value of the power battery detected by the second detection module with a set insulation resistance threshold, and sends an insulation resistance value abnormality prompt signal when the real-time insulation resistance value of the power battery is lower than the set insulation resistance threshold.

[0009] The control module communicates with the first detection module and the judgment module; when the control module receives a collision event signal sent by the first detection module, the control module, the second detection module, and the judgment module maintain low-voltage power supply; when the control module receives an abnormal insulation resistance value prompt signal sent by the judgment module, it determines that the power battery has a risk of thermal runaway.

[0010] Optionally, in the above-described system, the second detection module is also used to continuously detect the temperature of the power battery;

[0011] The judgment module is also used to analyze whether the real-time change of the power battery temperature detected by the second detection module meets the set rules. If not, a temperature abnormality prompt signal is sent.

[0012] When the control module receives at least one of the warning signals from the judgment module indicating abnormal insulation resistance and abnormal temperature, it determines that the power battery is at risk of thermal runaway.

[0013] Optionally, in the above system, the setting rule is that the temperature of the power battery cannot rise.

[0014] Optionally, the safety monitoring system further includes a display module that communicates with the control module. When the control module receives at least one of a collision event signal, an abnormal insulation resistance value warning signal, or an abnormal temperature warning signal, it controls the display module to display the corresponding information.

[0015] Optionally, the security monitoring system further includes a monitoring terminal that communicates with the control module to upload information from the control module to the monitoring platform.

[0016] Optionally, in the above system, the control module is connected to the first detection module, the second detection module, the judgment module, the display module, and the monitoring terminal via a CAN bus.

[0017] Optionally, in the above-described system, the battery management system of the electric vehicle includes the second detection module, and the vehicle controller of the electric vehicle includes the control module and the judgment module.

[0018] Optionally, in the above-described system, the battery management system of the electric vehicle includes the second detection module and the judgment module, and the vehicle controller of the electric vehicle includes the control module.

[0019] Optionally, in the above system, the insulation resistance threshold is set to 100Ω / V for DC and 500Ω / V for AC.

[0020] Optionally, in the above system, the first detection module is a collision sensor of an electric vehicle accident data recorder.

[0021] Compared with the prior art, the present invention has the following advantages: In the solution provided by the embodiments of the present invention, the risk of battery thermal runaway is continuously detected after the collision. Optionally, the method of detecting abnormal insulation resistance of the power battery and the method of detecting abnormal temperature of the power battery proposed in the embodiments are proposed to determine whether there is a risk of thermal runaway. Warning prompts can be given before thermal runaway occurs, which facilitates timely evacuation or preventive measures, improves battery safety after collision, and avoids battery pack spontaneous combustion due to insulation problems, etc.

[0022] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0023] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0024] Figure 1 This is a schematic diagram of the structure of a safety monitoring system for an electric vehicle power battery provided in an embodiment of the present invention;

[0025] Figure 2 This is another structural schematic diagram of a safety monitoring system for an electric vehicle power battery provided in an embodiment of the present invention;

[0026] Figure 3 This is a flowchart of a method for safety monitoring and control using a safety monitoring system for an electric vehicle power battery provided in an embodiment of the present invention. Detailed Implementation

[0027] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0028] refer to Figure 1 The diagram shows a structural block diagram of a safety monitoring system for an electric vehicle power battery provided by an embodiment of the present invention. Figure 1 The connection diagram shown represents a feasible implementation scheme of the safety monitoring system for electric vehicle power batteries provided in an embodiment of the present invention. The safety monitoring system specifically includes:

[0029] The first detection module is used to continuously detect whether a collision event has occurred in the electric vehicle. Optionally, the first detection module can be implemented by a collision sensor in the electric vehicle accident data recorder. The accident data recorder (EDR) can record the vehicle's operating parameters and safety status information in the three stages of the collision: before, during, and after the collision. It includes modules such as a collision sensor, a processor, a data control storage unit, and a backup power supply. The safety monitoring system provided in this embodiment of the invention can optionally use the collision sensor of the EDR system.

[0030] The second detection module is used to continuously detect the insulation resistance value of the power battery; the judgment module communicates with the second detection module, compares the real-time insulation resistance value of the power battery detected by the second detection module with a set insulation resistance threshold, and sends an insulation resistance value abnormality prompt signal when the real-time insulation resistance value of the power battery is lower than the set insulation resistance threshold; the control module communicates with the first detection module and the judgment module; when the control module receives a collision event signal sent by the first detection module, the control module, the second detection module and the judgment module maintain low voltage power supply; when the control module receives an insulation resistance value abnormality prompt signal sent by the judgment module, it determines that the power battery has a risk of thermal runaway.

[0031] In the safety monitoring system provided by this invention, the second detection module and the judgment module can be integrated together. Insulation resistance anomaly judgment is performed within the integrated structure of the second detection module and the judgment module. If the real-time insulation resistance value of the power battery is found to be lower than a set insulation resistance threshold, an insulation resistance anomaly warning signal is sent to the control module. Alternatively, the control module and the judgment module can be integrated together. After detecting the real-time insulation resistance value of the power battery, it is sent to the integrated module. Insulation resistance anomaly judgment is performed within the integrated module, and the resulting insulation resistance anomaly warning signal is processed by the control module.

[0032] Traditional safety monitoring systems typically cut off high voltage and shut down the system when the first detection module detects a collision, lacking continuous safety monitoring after a battery collision. However, the safety monitoring system provided in this embodiment of the invention maintains the control module, the second detection module, and the judgment module in a low-voltage powered state after a collision, allowing the second detection module to continue detecting the insulation resistance value of the power battery after the collision. The judgment module then compares the detected insulation resistance value to determine whether there is still an abnormal insulation resistance value after the collision, thus preventing thermal runaway and spontaneous combustion of the battery pack.

[0033] Optionally, the insulation resistance value of the power battery is the insulation resistance value between the main positive and main negative terminals of the power battery and the battery pack casing. Further, the first detection module may use the reference resistance method to measure the insulation resistance value of the power battery; the set insulation resistance threshold may be selected as 100Ω / V DC or 500Ω / V AC.

[0034] In the safety monitoring system provided in this embodiment of the invention, optionally, the criteria for judging thermal runaway may include not only the insulation resistance value of the power battery, but also the temperature change of the power battery. When at least one of the following occurs: abnormal insulation resistance or abnormal temperature, a risk of thermal runaway can be considered to exist. Furthermore, the detection of abnormal temperature can be achieved through a second detection module and a judgment module, or a separate detection and judgment module can be set up.

[0035] The safety monitoring system provided in this embodiment of the invention can optionally use a second detection module and a judgment module to detect abnormal insulation resistance and abnormal temperature. Specifically, the second detection module is also used to continuously detect the temperature of the power battery; the judgment module is also used to analyze whether the real-time change of the power battery temperature detected by the second detection module meets the set rules, and if not, to send a temperature abnormality prompt signal; when the control module receives at least one of the abnormal insulation resistance value prompt signal and the abnormal temperature prompt signal sent by the judgment module, it determines that the power battery has a risk of thermal runaway.

[0036] In the safety monitoring system provided by this invention, the second detection module continuously monitors the battery temperature, and the judgment module analyzes the battery temperature changes in real time, specifically by calculating the temperature rise of the power battery. After a collision, the system's high voltage is cut off, and the power battery temperature should decrease. Optionally, the setting rule is that the power battery temperature cannot rise. Therefore, when the judgment module analyzes that the real-time change in the power battery temperature is an increase, i.e., the power battery temperature after the collision is higher than the power battery temperature before the collision, it considers a temperature abnormality to have occurred and sends a temperature abnormality warning signal to the control module.

[0037] In the safety monitoring system provided in this embodiment of the invention, optionally, the safety monitoring system further includes a display module. The display module communicates with the control module. When the control module receives at least one of a collision event signal, an abnormal insulation resistance value prompt signal, and an abnormal temperature prompt signal, it controls the display module to display the corresponding information. When the control module receives a collision event signal, it can optionally control the display module to display a collision event prompt; when the control module receives an abnormal insulation resistance value prompt signal and / or an abnormal temperature prompt signal, it can optionally control the display module to display a thermal runaway pop-up prompt, and further, it can also control the display module to emit an alarm sound. Optionally, the display module is an instrument cluster of an electric vehicle.

[0038] In the safety monitoring system provided in this embodiment of the invention, optionally, the safety monitoring system further includes a monitoring terminal, which communicates with the control module and is used to upload information from the control module to a monitoring platform. Optionally, this includes information and data received by the control module as well as information and data sent by the control module. When a special event occurs, such as a collision event, abnormal power battery temperature, or abnormal power battery insulation resistance, relevant information about the special event can optionally be uploaded to the monitoring platform through the monitoring terminal to achieve data storage and monitoring.

[0039] In the safety monitoring system provided by this invention, the control module can optionally be connected to other modules via a CAN bus to achieve centralized monitoring. Specifically, the control module transmits information with the first detection module, the second detection module, the judgment module, the display module, and the monitoring terminal via a CAN bus network. Furthermore, the second detection module can be connected to the control module via the judgment module, and the judgment module analyzes and processes the data collected by the second detection module to generate corresponding command signals which are then output to the control module.

[0040] In the safety monitoring system provided in this embodiment of the invention, optionally, the second detection module can be implemented by the Battery Management System (BMS) of the electric vehicle. The BMS system is responsible for collecting the insulation resistance value and temperature data of the power battery. The control module can optionally be implemented by the Vehicle Control Unit (VCU), and the VCU can optionally establish a connection with the BMS system and the EDR system through a CAN bus network. Further, the judgment module can optionally be implemented within the VCU, where the BMS only collects the insulation resistance value and temperature data of the power battery and sends the collected data to the VCU for judgment and processing; or the judgment module can optionally be implemented within the BMS, where the BMS collects the insulation resistance value and temperature data of the power battery and determines whether there is an abnormal insulation resistance value and / or an abnormal temperature, and sends the judgment result to the VCU.

[0041] Furthermore, the VCU is connected to the display module and monitoring terminal via a CAN bus. Information such as collision events, abnormal battery temperature events, and abnormal battery insulation resistance values ​​are displayed on the display module (e.g., an instrument panel) and uploaded to the monitoring terminal. The VCU can also optionally connect to other high-voltage electrical components, such as a Power Distribution Unit (PDU), On-Board Charger (OBC), and DC-DC converter. When a risk of thermal runaway is detected, the VCU sends a CAN message to the PDU and other modules to reduce the high voltage, thus disconnecting the high-voltage electrical components. In some embodiments, the PDU, OBC, and DC-DC converter form a vehicle-mounted three-in-one structure, which can optionally connect to the VCU via a CAN bus.

[0042] This invention also provides a method for safety monitoring using the above-described safety monitoring system for electric vehicle power batteries, with a general flowchart provided below. Figure 3 The safety monitoring method for the electric vehicle power battery includes:

[0043] The EDR system continuously monitors whether a collision event has occurred in the electric vehicle. Optionally, the BMS system continuously monitors the insulation resistance value of the power battery and / or continuously monitors the temperature of the power battery.

[0044] After the EDR system detects a collision event, it sends an EDR collision event lock signal to the VCU. The VCU cuts off the high-voltage electrical components, but at the same time keeps the VCU and BMS powered on at low voltage. The BMS continues to monitor the insulation resistance value of the power battery and / or continuously monitors the temperature of the power battery. Optional instruments display collision information.

[0045] When the VCU receives the EDR collision event lock signal and the BMS detects abnormal insulation resistance and / or temperature of the power battery, the VCU sends a CAN message to notify the PDU and other devices to reduce the high voltage. The BMS then reduces the high voltage and simultaneously uploads the temperature and / or insulation information of the power battery in real time. Information such as internal short circuits (abnormal insulation resistance) and / or abnormal temperatures are uploaded to the VCU. The VCU sends special event information (such as collision or thermal runaway) to the instrument panel. Upon receiving the information, the instrument panel can optionally display a thermal runaway pop-up window and issue an alarm sound. The special event information is uploaded to the monitoring platform through the monitoring terminal.

[0046] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A safety monitoring system for an electric vehicle traction battery, characterized in that The application relates to a safety monitoring system for a power battery of an electric vehicle. The safety monitoring system comprises: a first detection module for continuously detecting whether a collision event occurs to the electric vehicle; a second detection module for continuously detecting an insulation resistance value of the power battery; a judgment module in communication with the second detection module, for comparing the real-time insulation resistance value of the power battery detected by the second detection module with a set insulation resistance threshold value, and sending a prompt signal of an abnormal insulation resistance value when the real-time insulation resistance value of the power battery is lower than the set insulation resistance threshold value; and a control module in communication with the first detection module and the judgment module, for keeping the control module, the second detection module and the judgment module powered on at low voltage when the control module receives a collision event signal sent by the first detection module, and judging that the power battery has a risk of thermal runaway when the control module receives the prompt signal of the abnormal insulation resistance value sent by the judgment module. The second detection module is further configured to continuously detect a temperature of the power battery. The judgment module is further configured to analyze whether a real-time change of the temperature of the power battery detected by the second detection module meets a set rule, and send a prompt signal of an abnormal temperature if not. The control module judges that the power battery has a risk of thermal runaway when the control module receives at least one of the prompt signal of the abnormal insulation resistance value and the prompt signal of the abnormal temperature sent by the judgment module.

2. The safety monitoring system of a power battery of an electric vehicle according to claim 1, characterized in that, The set rule is that the temperature of the power battery cannot rise. The safety monitoring system further comprises a display module in communication with the control module, for displaying corresponding information when the control module receives at least one of a collision event signal, a prompt signal of an abnormal insulation resistance value and a prompt signal of an abnormal temperature. The safety monitoring system further comprises a monitoring terminal in communication with the control module, for uploading information of the control module to a monitoring platform.

3. The safety monitoring system of a power battery of an electric vehicle according to claim 2, characterized in that, The control module is connected to the first detection module, the second detection module, the judgment module, the display module and the monitoring terminal through a CAN bus.

4. The safety monitoring system of a power battery of an electric vehicle according to claim 2, characterized in that, A battery management system of the electric vehicle comprises the second detection module, and a vehicle controller of the electric vehicle comprises the control module and the judgment module.

5. The safety monitoring system of a power battery of an electric vehicle according to claim 4, characterized in that, A battery management system of the electric vehicle comprises the second detection module and the judgment module, and a vehicle controller of the electric vehicle comprises the control module.

6. The safety monitoring system of a power battery of an electric vehicle according to claim 5, characterized in that, The set insulation resistance threshold value is 100 ohms per volt in direct current and 500 ohms per volt in alternating current.

7. The safety monitoring system of a power battery of an electric vehicle according to claim 2, characterized in that, The first detection module is a collision sensor of an electric vehicle accident data recorder.

8. The safety monitoring system of a power battery of an electric vehicle according to claim 2, characterized in that, ​ 9. The safety monitoring system of a power battery of an electric vehicle according to claim 1, characterized in that, ​ 10. The safety monitoring system of a power battery of an electric vehicle according to claim 1, characterized in that, ​

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