An air pressure monitoring system and monitoring device for thermal event monitoring of electric vehicle power battery packs

Abstract

The present invention relates to an air pressure monitoring system and a monitoring device for monitoring thermal events of electric vehicle power battery packs, including a controller unit, a pressure detection unit, a power conversion unit, a data interface unit and an abnormal state monitoring unit; the pressure detection unit, the data interface unit and the abnormal state monitoring unit are respectively electrically connected to the controller unit and communicate data, the controller unit receives the monitoring data from the pressure detection unit, and forwards it to the data interface unit after processing, and the data interface unit interacts with the vehicle system. The present invention utilizes the air pressure detection principle, and monitors the rapid changes in air pressure in the battery pack inside the power battery module in real time, thereby realizing the monitoring of power battery thermal events. It has high detection precision, fast speed, good detection accuracy, and no false alarms or missed alarms. Different from the principle of gas component detection, the present invention uses non-electrochemical reaction detection, high reliability and long service life.

Description

Technical Field

[0001] The present invention relates to the field of power battery safety technology, and in particular to an air pressure monitoring system and a monitoring device for monitoring thermal events of a power battery pack of an electric vehicle. Background Art

[0002] According to the mandatory requirements for electric vehicle power battery safety, a thermal event alarm signal should be provided within five minutes before causing danger to the cabin members. Therefore, electric vehicles need to be mandatory to install devices and monitoring systems that can monitor power battery thermal events. Currently, commonly used thermal event detection methods include voltage detection, temperature detection, and gas detection technology, but the relevant detection technologies have certain limitations.

[0003] Voltage detection technology determines whether a thermal event has occurred by detecting the output voltage value of the battery cell. When a battery cell fails, the voltage across the battery cell will fluctuate greatly. When the event is detected, the sensor will send a warning to the battery management system. However, when the load changes suddenly, the voltage across the battery will fluctuate, so the voltage detection method is prone to false alarms. And because there is a certain deviation in the internal resistance of different battery cells, the detection accuracy is limited.

[0004] Temperature detection technology determines whether a thermal event has occurred by detecting the temperature of the battery cell casing. When a battery cell fails, the battery cell temperature will rise. When the threshold is exceeded, the sensor will send a warning to the battery management system. Temperature detection is an early detection technology and is also a commonly used power battery monitoring technology. Due to the slow temperature conduction speed, when a thermal event is detected, the time left for members to escape cannot meet the requirements of the latest laws and regulations.

[0005] Gas detection technology determines whether a thermal event has occurred by detecting the gas composition in the battery pack. When a battery cell fails, the components in the battery cell will fill the battery pack. When the presence of related gases is detected, the sensor will send a warning to the battery management system. Gas detection technology relies on the chemical composition of the battery. Batteries made of different materials produce different gas components when the battery cell fails, so there is also the possibility of underreporting. At the same time, sensors based on electrochemical characteristics have problems such as short life and low reliability. Summary of the invention

[0006] The technical problem solved by the present invention is to provide an air pressure monitoring system and a monitoring device for monitoring thermal events of electric vehicle power battery packs with high detection precision, fast speed and good accuracy.

[0007] The technical solution adopted by the present invention to solve its technical problem is:

[0008] A pneumatic pressure monitoring system for monitoring thermal events of a power battery pack of an electric vehicle comprises a controller unit, a pressure detection unit, a power supply conversion unit, a data interface unit and an abnormal state monitoring unit; the pressure detection unit, the data interface unit and the abnormal state monitoring unit are respectively electrically connected to and communicate data with the controller unit, the power supply conversion unit is used to monitor the power supply of the system, the pressure detection unit is used to monitor the pressure of the power battery module, the abnormal state monitoring unit monitors the operating state of the high-precision pneumatic pressure monitoring system, the controller unit receives monitoring data from the pressure detection unit, and forwards it to the data interface unit after processing, and the data interface unit interacts with a vehicle system.

[0009] Furthermore, the controller unit includes a processor chip and microcontroller peripheral components.

[0010] Furthermore, the power supply conversion unit includes an EMC / EMI circuit module and a voltage stabilization circuit module.

[0011] Furthermore, the pressure detection unit includes a low-power control circuit module and a pressure detection chip.

[0012] Furthermore, the data interface unit includes a CAN bus transceiver, a LIN bus transceiver and a PWM drive circuit module.

[0013] Furthermore, the data interface unit also includes a bus interference suppression circuit module.

[0014] Furthermore, the abnormal state monitoring unit includes a voltage detection module, a temperature detection module, a sensor chip detection module and a data interface detection module.

[0015] A pressure monitoring device for monitoring thermal events of a power battery pack of an electric vehicle comprises a main shell, a PCB board and a bottom shell, wherein the PCB board comprises the above-mentioned controller unit, pressure detection unit, power supply conversion unit, data interface unit and abnormal state monitoring unit circuit module, the main shell and the bottom shell are fixed by fixing buckles and elastic bayonet, and the PCB board is fixed inside the main shell and the bottom shell by elastic buckles and a plurality of support columns.

[0016] Furthermore, the main shell includes a main housing, a data cable interface is provided at the front end of the main housing, and the data cable interface is integrally formed with the main housing to form the main shell.

[0017] Furthermore, the left and right sides of the front end of the main shell are also provided with fixing ears and feet for fixing the monitoring device, and the left and right sides and the rear end are also provided with the fixing buckles, and the left and right sides and the rear end of the bottom shell are provided with the elastic bayonet used in conjunction with the fixing buckles.

[0018] Furthermore, a PCB support column, a PCB guide column and the elastic buckle are arranged inside the main shell, the PCB support column is used to support the PCB board, the PCB guide column is used to fix and position the PCB board, and the elastic buckle is used to clamp and fix the PCB board to the main shell; a PCB stabilizing column is also arranged inside the bottom shell.

[0019] The present invention utilizes the air pressure detection principle and monitors the rapid changes in air pressure in the battery pack inside the power battery module in real time, thereby realizing the monitoring of thermal events in the power battery pack. It has high detection precision, fast speed, good detection accuracy, and no false alarms or missed alarms. Different from the principle of gas component detection, the present invention uses non-electrochemical reaction detection, has high reliability and long service life. Moreover, due to the fluidity of air, there is no blind spot in air pressure detection, so the sensor has no special requirements for the installation position and is easy to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a system principle diagram of the monitoring system of the present invention;

[0021] Figure 2 It is a main module diagram of the system of the present invention;

[0022] Figure 3 for Figure 2 Partial circuit schematic diagram of the power supply conversion unit;

[0023] Figure 4 for Figure 2 Partial circuit schematic diagram of the pressure detection unit;

[0024] Figure 5 for Figure 2 Partial circuit schematic diagram of abnormal state monitoring unit;

[0025] Figure 6 for Figure 2 Partial circuit schematic diagram of the data interface unit;

[0026] Figure 7 This is the structural diagram of the monitoring device of the present invention;

[0027] Figure 8 for Figure 7 Diagram of the internal structure of the middle main shell;

[0028] Fig. 9 for Figure 8 A top view of

[0029] Fig.10 This is a top view of the PCB board assembled to the main shell;

[0030] Fig.11 for Figure 7 Combined state diagram.

[0031] The markings in the figure are:

[0032] 1. Main shell, 2. PCB board, 3. Bottom shell;

[0033] 101. Main shell, 102. Data cable interface, 1021. PIN pin 103. Fixed ear foot, 104. PCB support column, 1041. Front PCB support column, 1042. Middle PCB support column, 1043. Rear PCB support column, 105. PCB guide column, 106. Elastic buckle, 107. Fixed buckle, 108. Label window, 301. PCB stabilizing column, 302. Elastic bayonet. DETAILED DESCRIPTION

[0034] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0036] The present invention provides an air pressure monitoring system and a monitoring device for monitoring thermal events of a power battery pack of an electric vehicle.

[0037] like Figure 1 As shown, it is a schematic diagram of an air pressure monitoring system for monitoring thermal events of electric vehicle power battery packs according to the present invention. The monitoring system includes a controller unit, a pressure detection unit, a power supply conversion unit, a data interface unit and an abnormal state monitoring unit. The pressure detection unit, the data interface unit and the abnormal state monitoring unit are electrically connected and communicate data with the controller unit respectively.

[0038] The power supply conversion unit is used to monitor the power supply of the system, and the power supply conversion unit is used to supply power to the pressure detection unit, the controller unit, the data interface unit and the abnormal state monitoring unit. Figure 2As shown, the power supply conversion unit mainly includes an EMC / EMI module and a voltage stabilization module. The EMC / EMI module is mainly used to shield interference signals, suppress interference pulses and excessive input power on the power line, and protect the electronic components and chips of each unit of the monitoring system.

[0039] like Figure 3 As shown in the figure, it is the circuit schematic diagram of the EMC / EMI module, including TVS tube D10, low-pass filter (composed of inductor L5, capacitor C104 and capacitor C105), anti-reverse connection circuit (composed of MOS tube Q5, resistor R53, capacitor C103 and voltage stabilizing diode D11) and filter circuit (composed of capacitor C106, capacitor C107 and capacitor C108). The TVS tube is used to suppress interference pulses and excessive input voltage on the power line, the low-pass filter is used to filter out interference signals with a frequency higher than 10KHz, and the anti-reverse connection circuit has the characteristics of low conduction voltage drop, which makes the power consumption of the whole machine lower. It also includes magnetic beads FB5, which are used to filter out megahertz-level interference signals.

[0040] The voltage stabilizing module of the power supply conversion unit is composed of a voltage stabilizing chip and peripheral electronic components, and is used to convert the input voltage into a 5V voltage used on the PCB board.

[0041] Among them, the pressure detection unit is used to monitor the pressure data of the electric vehicle power battery pack module. The power battery thermal event is monitored by real-time monitoring of the pressure data of the battery pack in the power battery pack module. After the battery cell fails, the air pressure in the battery pack can change quickly. Therefore, by monitoring the pressure of the battery pack, the pressure sensor can respond quickly, thereby realizing the rapid monitoring and response of the power battery thermal event, providing sufficient time for personnel to escape. Due to the fluidity of air, there is no blind spot for air pressure detection, so the sensor has no special requirements for the installation position and is easy to use.

[0042] like Figure 2 As shown in FIG. 1 , the pressure detection unit transmits the collected power battery pack pressure data to the controller unit. After being processed by the controller unit, the data is forwarded through the data interface unit and then sent to the vehicle system by the data interface unit. The pressure detection unit includes a low-power control module and a pressure detection chip, such as Figure 4 As shown in the figure, it is the circuit schematic diagram of the pressure detection unit, including the pressure detection chip U32 and the low-power control module circuit (composed of MOS tube Q6, capacitor C118 and resistor R60). The pressure detection chip U32 collects pressure data, and the low-power control module provides a low-power mode for the pressure detection unit, which can effectively save energy. The detection range of the pressure detection chip U32 is 50kpa~300kpa, the detection accuracy is ±1%, and the pressure fluctuation threshold is ±3kpa; the pressure rise rate exceeds 0.5kpa / s, which will also trigger an alarm. Figure 4 As shown, the pressure detection unit is further used to filter out megahertz-level interference signals through magnetic beads FB6 to improve detection accuracy.

[0043] Among them, the controller unit includes a core processor module, which is composed of a processor chip and peripheral components. The controller unit is the core control module of the present invention and is mainly used for data processing, data forwarding and communication functions.

[0044] The data interface unit is used for data transmission and communication functions. On the one hand, it is used for data collection, and on the other hand, it interacts with the vehicle system for data transmission. Figure 2 As shown, it includes a CAN bus transceiver, a LIN bus transceiver and a PWM drive circuit module.

[0045] like Figure 6 As shown in the figure, it is the circuit schematic diagram of the data interface unit. The drawing takes the CAN bus interface as an example. The control chip U31 is responsible for the conversion of the differential level and CMOS level of the CAN bus. The inductor L6, diode D12, capacitor C110, capacitor C111, resistor R55, resistor R56 and C113 on the left together constitute the interface protection circuit. Through multiple groups of filtering, the interference on the bus is suppressed to prevent the occurrence of communication errors.

[0046] Among them, the abnormal state monitoring unit mainly monitors the operating state of the high-precision air pressure monitoring system of the present invention, such as Figure 2 As shown, the abnormal state monitoring unit mainly includes a voltage detection module, a temperature detection module, a sensor chip detection module and a data interface detection module. Figure 5 As shown in the figure, it is the circuit schematic diagram of the abnormal state monitoring unit. Resistors R57 and R59 form a voltage divider circuit, which divides the power supply voltage converted by the power supply unit into a reasonable value for the processor to use, and then calculates the power supply voltage value, thereby realizing the monitoring of the operation status of the entire monitoring system. If the power supply voltage fluctuates, the processor will perform an early warning. The microcontroller has a temperature monitoring function inside, and the monitored temperature value is used to correct the air pressure value.

[0047] The operation process of the monitoring system is as follows:

[0048] The pressure detection unit is used for (real-time) pressure collection of the power battery pack, converting the collected pressure analog signal into a pressure digital signal, sending the pressure digital signal to the controller unit, and performing data processing and analysis on the pressure digital signal through the processor to accurately determine whether there is a power battery thermal event. The abnormal status monitoring unit is used to monitor the operating status of the system in real time to ensure the normal operation and early warning of the system. The data interface unit is used to communicate and interact with the vehicle system and send system events to the vehicle system in real time.

[0049] like Figure 7-11 As shown, the present invention also provides an air pressure monitoring device for monitoring thermal events of electric vehicle power battery packs, including a main shell 1, a PCB board 2 and a bottom shell 3, wherein the PCB board includes the above-mentioned controller unit, pressure detection unit, power supply conversion unit, data interface unit and abnormal state monitoring unit circuit module. The main shell 1 and the bottom shell 3 are fixed by fixing buckles and elastic bayonet, and the PCB board 2 is fixed inside the main shell and the bottom shell by elastic buckles and a plurality of support columns.

[0050] The present invention realizes the fixing work of the entire monitoring device through a plurality of buckles and buckle structures, making the processing and subsequent maintenance work simpler and more convenient.

[0051] like Figure 8 As shown in the figure, it is an internal structure diagram of the main shell, the main shell includes a main shell 101, a data cable interface 102 is provided at the front end of the main shell 101, and the data cable interface 102 is integrally formed with the main shell 101 to form the main shell 1. As shown in the figure, the front left and right sides of the main shell 101 are also provided with fixed ear feet 103 for fixing the monitoring device of the present invention, and the left and right sides and the rear end are also provided with fixed buckles 107, correspondingly, as shown in the figure. Figure 7 As shown, the left and right sides and the rear end of the bottom shell 3 are provided with elastic bayonet 302 used in conjunction with the fixing buckle 107. In order to stably fix the main shell and the bottom shell, the fixing buckles and elastic bayonet on the left and right sides of the main shell and the bottom shell are both provided with two groups in front and back, and the fixing buckle and elastic bayonet on the rear end are provided with one group, which is arranged in the middle. The monitoring device of the present invention can be quickly assembled and disassembled through the fixing buckles and elastic bayonet on the left and right sides and the rear end.

[0052] like Figure 7 As shown, the main housing 101 is provided with a PCB support column 104, a PCB guide column 105 and an elastic buckle 106. The PCB support column is used to support the PCB board, the PCB guide column is used to fix and position the PCB board, and the elastic buckle is used to clamp and fix the PCB board to the main housing. Figure 8 and Fig. 9 As shown, three groups of PCB support columns 104 are arranged on the left and right sides of the main housing 101 to form front support columns 1041, middle support columns 1042 and rear support columns 1043, and are symmetrically designed to stably support the PCB board inside the main housing. The PCB guide column 105 is used for positioning the PCB board during installation, and is also used for later fixing work to clamp the PCB board, thereby preventing the PCB board from deflecting.

[0053] like Fig. 9 As shown, the PCB board is installed along the PCB guide column, and the PCB board is clamped and fixed inside the main housing 101 by the elastic buckle 106. Because there is no PCB fixing structure at the front end of the main housing, as shown Figure 7 As shown, a PCB stabilizing column 301 is also provided inside the bottom shell 3. The PCB stabilizing column is arranged inside the bottom shell 3 front and back, and cooperates with the PCB supporting column 104 and the elastic buckle 106 to stably fix the PCB board 2 inside the main shell.

[0054] like Fig.11 As shown in FIG. 1 , it is an assembly diagram of the monitoring device of the present invention, the data cable interface 102 is connected to the cable, and the cable is fixedly connected to the data cable interface through the port. Among them, the fixed ear feet 103 are arranged on the left and right sides of the main housing, such as Fig. 9 As shown, a strip hole 1031 is also provided at the fixing buckle of the fixing ear foot 103 near the front end of the main shell, which is used to clamp and fix the elastic buckle on the bottom shell 3 with the fixing buckle on the main shell, while improving its stability and preventing the elastic buckle on the bottom shell 3 from vibrating and detaching.

[0055] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An air pressure monitoring device for monitoring thermal events of electric vehicle power battery packs, characterized in that: It comprises a main shell, a PCB board and a bottom shell, wherein the PCB board comprises an air pressure monitoring system for monitoring thermal events of a power battery pack of an electric vehicle, and the air pressure monitoring system comprises a controller unit, a pressure detection unit, a power supply conversion unit, a data interface unit and an abnormal state monitoring unit; the pressure detection unit, the data interface unit and the abnormal state monitoring unit are respectively electrically connected and communicate data with the controller unit, the power supply conversion unit is used for power supply of the monitoring system, the pressure detection unit is used for monitoring the pressure of the power battery module, the abnormal state monitoring unit monitors the operating state of the air pressure monitoring system, the controller unit receives monitoring data from the pressure detection unit, and forwards it to the data interface unit after processing, and the data interface unit interacts with the vehicle system; The main shell and the bottom shell are fixed by fixing buckles and elastic bayonet holes, and the PCB board is fixed inside the main shell and the bottom shell by elastic buckles and a plurality of supporting columns; The main shell comprises a main housing, a data cable interface is provided at the front end of the main housing, and the data cable interface is integrally formed with the main housing; The front left and right sides of the main shell are also provided with fixing ears for fixing the monitoring device, and the left and right sides and the rear end are also provided with the fixing buckle, and the left and right sides and the rear end of the bottom shell are provided with the elastic bayonet used in conjunction with the fixing buckle; the fixing ears are also provided with a strip hole near the fixing buckle at the front end of the main shell, and the strip hole is used for the elastic bayonet on the bottom shell to be clamped and fixed with the fixing buckle on the main shell; The main housing is provided with PCB support columns, PCB guide columns and the elastic buckle, the PCB support columns are used to support the PCB board, the PCB guide columns are used to fix and position the PCB board, and the elastic buckle is used to clamp and fix the PCB board to the main housing. The PCB support columns are provided in three groups, which are respectively provided on the left and right sides of the main housing to form a front support column, a middle support column and a rear support column, and are symmetrically designed; A PCB stabilizing column is also provided inside the bottom shell. The PCB stabilizing column is arranged front to back, is provided inside the bottom shell, and cooperates with the PCB supporting column and the elastic buckle to stably fix the PCB board inside the main shell.

2. The air pressure monitoring device for monitoring thermal events of electric vehicle power battery packs according to claim 1, characterized in that: The controller unit includes a processor chip and microcontroller peripheral components.

3. The air pressure monitoring device for monitoring thermal events of electric vehicle power battery packs according to claim 1, characterized in that: The power supply conversion unit includes an EMC / EMI circuit module and a voltage stabilization circuit module.

4. The air pressure monitoring device for monitoring thermal events of electric vehicle power battery packs according to claim 1, characterized in that: The pressure detection unit includes a low-power control circuit module and a pressure detection chip.

5. The air pressure monitoring device for monitoring thermal events of electric vehicle power battery packs according to claim 1, characterized in that: The data interface unit includes a CAN bus transceiver, a LIN bus transceiver and a PWM drive circuit module.

6. The air pressure monitoring device for monitoring thermal events of electric vehicle power battery packs according to claim 5, characterized in that: The data interface unit also includes a bus interference suppression circuit module.

7. The air pressure monitoring device for monitoring thermal events of electric vehicle power battery packs according to claim 1, characterized in that: The abnormal state monitoring unit includes a voltage detection module, a temperature detection module, a sensor chip detection module and a data interface detection module.

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