Battery over-temperature protection system and vehicle with same

Abstract

The invention provides a battery over-temperature protection system and a vehicle with the same. The battery over-temperature system comprises a battery module, a battery over-temperature protection circuit and an isolation power supply. The battery module consists of a plurality of single batteries; the input end of the battery over-temperature protection circuit is connected with the battery module, and the output end of the battery over-temperature protection circuit is electrically connected with a controller of the vehicle; the isolation power supply is connected with the battery over-temperature protection circuit and supplies power to the battery over-temperature protection circuit; wherein the battery over-temperature protection circuit comprises a battery temperature acquisition circuit, a battery temperature comparison circuit and an alarm signal output circuit, the battery temperature acquisition circuit is used for acquiring a voltage signal of a temperature corresponding to a single battery in real time, and the battery temperature comparison circuit is used for judging whether the voltage signal exceeds a preset threshold voltage or not; the alarm signal output circuit is used for generating and sending an alarm signal to the controller. The problems that in the prior art, a vehicle battery management system loses efficacy, and safety accidents are caused by high temperature of a battery are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle power supply, and in particular to a battery over-temperature protection system and a vehicle having the same. Background Art

[0002] Nowadays, during battery use, external factors such as discharge, ambient temperature, and charging can cause abnormalities in internal voltage, current, and temperature, impacting battery safety, performance, and lifespan. For example, when a battery overheats, the excessive temperature can intensify chemical reactions within the battery, causing the electrolyte to decompose and generate a large amount of heat. This can further lead to battery overheating, fire, or even explosion, seriously affecting human and machine safety.

[0003] At present, the BMS battery management system mainly monitors, controls and manages the battery's various performance functions to ensure the battery's safe, stable and long life operation; however, the BMS may fail, resulting in the battery system's safety not being guaranteed.

[0004] Currently, no effective solutions have been proposed for the above technical problems. Summary of the Invention

[0005] The main purpose of the present invention is to provide a battery over-temperature protection system and a vehicle having the same, so as to solve the problem of failure of the vehicle battery management system in the prior art and safety accidents caused by high temperature of the battery.

[0006] To achieve the above-mentioned purpose, according to one aspect of the present invention, a battery over-temperature protection system is provided, comprising: a battery module, the battery module being composed of a plurality of single cells; a battery over-temperature protection circuit, the input end of the battery over-temperature protection circuit being connected to the battery module, and the output end of the battery over-temperature protection circuit being electrically connected to a controller of a vehicle; an isolated power supply, the isolated power supply being connected to the battery over-temperature protection circuit and supplying power to the battery over-temperature protection circuit; wherein the battery over-temperature protection circuit comprises a battery temperature acquisition circuit, a battery temperature comparison circuit, and an alarm signal output circuit, the battery temperature acquisition circuit being used to acquire a voltage signal corresponding to the temperature of the single cell in real time, the battery temperature comparison circuit being used to determine whether the voltage signal exceeds a preset threshold voltage, and the alarm signal output circuit being used to generate and send an alarm signal to the controller.

[0007] Furthermore, the battery temperature acquisition circuit includes: a sixth resistor, the input end of the sixth resistor is connected to the isolated power supply; a temperature sensor, one end of the temperature sensor is connected to the output end of the sixth resistor, and the other end of the temperature sensor is grounded, the temperature sensor and the sixth resistor are connected in series to form a first voltage divider circuit, and the output end of the first voltage divider circuit is connected to the inverting input end of the comparator; wherein the first voltage divider circuit is used to generate a voltage signal corresponding to the temperature of the single cell.

[0008] Furthermore, the battery temperature comparison circuit includes a threshold voltage reference circuit, which includes: a resistor network, the resistor network is connected to the non-inverting input terminal of the comparator, and the resistor network provides a threshold voltage for the comparator, wherein the resistor network includes a first resistor, a second resistor, a third resistor, a fourth resistor and a fifth resistor, the first resistor and the fourth resistor are arranged in series on the first circuit, the third resistor and the fifth resistor are arranged in series on the second circuit, the first circuit is connected in parallel with the second circuit, and one end of the second resistor is arranged on the circuit connecting the third resistor and the fifth resistor, and the other end of the second resistor is arranged on the circuit connecting the first resistor and the fourth resistor, the non-inverting input terminal of the comparator is connected to the first circuit, the inverting input terminal of the comparator is connected to the temperature sensor, and the output terminal of the comparator is connected to the input terminal of the alarm signal output circuit.

[0009] Furthermore, the third resistor is composed of two resistors, the two resistors include an eleventh resistor and a twelfth resistor; the circuit between the first resistor and the second resistor and the fourth resistor forms a second voltage divider circuit, the second voltage divider circuit is used to provide a first threshold voltage to the non-inverting input terminal of the comparator, and one end of the first resistor and the second resistor is grounded; the circuit between the fifth resistor and the eleventh resistor and the twelfth resistor in series forms a third voltage divider circuit, and the third voltage divider circuit and the second voltage divider circuit are used to provide a second threshold voltage to the non-inverting input terminal.

[0010] Furthermore, the output end of the comparator is used to generate a control signal. When the voltage signal is less than a first threshold voltage, the control signal is a high level signal. When the voltage signal is greater than a second threshold voltage, the control signal is a low level signal.

[0011] Furthermore, the alarm signal output circuit includes: a first NMOS tube, the gate of the first NMOS tube is connected to the output end of the comparator to form the input end of the alarm signal output circuit, the source of the first NMOS tube is grounded, and when the control signal is a high-level signal, the source and drain of the first NMOS tube are turned on, and when the control signal is a low-level signal, the source and drain of the first NMOS tube are not turned on; an isolation optocoupler, the drain of the first NMOS tube is connected to the second pin of the isolation optocoupler, and the first pin of the isolation optocoupler is connected to the isolation power supply through a seventh resistor. When the source and drain of the first NMOS are turned on, the third pin and fourth pin of the isolation optocoupler are turned on, and the fourth pin is connected to the independent power supply; a load driving module, the third pin of the isolation optocoupler is connected to the input end of the load driving module, and the output end of the load driving module is electrically connected to the controller to send the control signal to the controller.

[0012] Furthermore, the load driving module includes: a first driving module, the first driving module includes a second NMOS tube, the gate of the second NMOS tube is connected to the third pin of the isolation optocoupler, the source of the second NMOS tube is grounded, when the control signal is a high-level signal, the source and drain of the second NMOS tube are conductive, and when the control signal is a low-level signal, the source and drain of the second NMOS tube are not conductive; a second driving module, the second driving module includes a first PMOS tube, the gate of the first PMOS tube is connected to the drain of the second NMOS tube, and the source of the first PMOS tube is connected to an independent power supply; when the control signal is a high-level signal, the source and drain of the first PMOS tube are conductive, and when the control signal is a low-level signal, the source and drain of the first PMOS tube are not conductive; a relay, the input end of the relay is connected to the source of the first PMOS tube, the output end of the relay is electrically connected to the controller, when the control signal is a high-level signal, the normally closed switch of the relay is disconnected, and when the control signal is a low-level signal, the normally closed switch of the relay is closed.

[0013] Furthermore, a ninth resistor is provided between the third pin of the isolation optocoupler and the gate of the second NMOS transistor, and a tenth resistor is provided between the drain of the first PMOS transistor and the gate of the first PMOS transistor.

[0014] Furthermore, the battery over-temperature protection circuit is provided with multiple battery temperature comparison circuits, and the multiple battery temperature comparison circuits are arranged in parallel. The multiple parallel-arranged battery temperature comparison circuits are respectively connected in series with the first NMOS tube and the isolation optocoupler to form a combination circuit, and the combination circuit is arranged in series with the load driving module.

[0015] According to another aspect of the present invention, a vehicle is provided, comprising a battery over-temperature protection system, wherein the battery over-temperature protection system is the above-mentioned battery over-temperature protection system.

[0016] By applying the technical solution of the present invention, the input end of the battery over-temperature protection circuit is directly connected to the battery module to detect the temperature information of the single cell in real time. The output end is electrically connected to the vehicle's controller. Once an over-temperature state is detected, an alarm signal can be immediately sent to the controller to trigger the subsequent safety processing logic, providing comprehensive over-temperature protection measures for the battery, significantly improving the safety and reliability of electric vehicles and other application fields. The battery temperature acquisition circuit is responsible for collecting the temperature information of each single cell in the battery module, and the battery temperature comparison circuit compares the collected temperature signal with the preset threshold to determine whether the current battery temperature exceeds the safe range. When the battery temperature exceeds the set threshold, an alarm signal is generated and output. The alarm signal is transmitted to the vehicle's controller through relay contacts or dry contacts. This solution solves the problem of failure of the vehicle battery management system in the prior art and safety accidents caused by high temperature of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0018] Figure 1 A functional block diagram of an embodiment of a battery over-temperature protection system according to the present invention is shown;

[0019] Figure 2 A circuit principle topology diagram of an embodiment of a battery over-temperature protection system according to the present invention is shown;

[0020] Figure 3 A circuit schematic diagram of a first embodiment of a battery over-temperature protection system according to the present invention is shown;

[0021] Figure 4 A circuit schematic diagram of a second embodiment of a battery over-temperature protection system according to the present invention is shown;

[0022] Figure 5 Schematic diagram showing resistance values ​​of an embodiment of a temperature sensor according to the present invention;

[0023] Figure 6 A circuit schematic diagram of a first embodiment of a threshold reference voltage circuit according to the present invention is shown;

[0024] Figure 7 A circuit schematic diagram of a second embodiment of a threshold reference voltage circuit according to the present invention is shown;

[0025] Figure 8 FIG. 4 shows a circuit principle diagram of a third embodiment of a threshold reference voltage circuit according to the present invention.

[0026] The above drawings include the following reference numerals:

[0027] 1. Battery module; 10. Comparator;

[0028] 2. Battery temperature acquisition circuit; 20. Temperature sensor; 21. First resistor; 22. Second resistor; 23. Third resistor; 24. Fourth resistor; 25. Fifth resistor; 26. Sixth resistor; 27. Seventh resistor; 28. Eighth resistor; 29. ​​Ninth resistor; 30. Tenth resistor; 231. Eleventh resistor; 232. Twelfth resistor;

[0029] 3. Battery temperature comparison circuit; 31. First capacitor; 32. Second capacitor;

[0030] 4. Alarm signal output circuit; 41. First NMOS transistor; 42. First diode; 43. Isolation optocoupler; 44. Second NMOS transistor; 45. Second diode; 46. First PMOS transistor; 47. Third diode; 48. Fourth diode;

[0031] 5. Isolation power supply; 50. Relay. DETAILED DESCRIPTION

[0032] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0033] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0034] It should be noted that the terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way are interchangeable where appropriate, so that the embodiments of the application described herein can, for example, be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or circuits is not necessarily limited to those steps or circuits clearly listed, but may include other steps or circuits that are not clearly listed or inherent to these processes, methods, products or devices.

[0035] Now, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in a variety of different forms and should not be interpreted as being limited to the embodiments described herein. It should be understood that these embodiments are provided to make the disclosure of this application thorough and complete, and to fully convey the concepts of these exemplary embodiments to those of ordinary skill in the art. In the accompanying drawings, for the sake of clarity, the thickness of layers and regions may be exaggerated, and the same reference numerals are used to represent the same devices, and thus their descriptions will be omitted.

[0036] Combine Figures 1 to 8 As shown, according to a specific embodiment of the present application, a battery over-temperature protection system and a vehicle having the same are provided.

[0037] Specifically, if Figure 1 As shown, the battery over-temperature protection system includes: a battery module 1, a battery over-temperature protection circuit and an isolated power supply 5, the battery module 1 is composed of multiple single cells; the input end of the battery over-temperature protection circuit is connected to the battery module 1, and the output end of the battery over-temperature protection circuit is electrically connected to the vehicle controller; the isolated power supply 5 is connected to the battery over-temperature protection circuit and supplies power to the battery over-temperature protection circuit; wherein, the battery over-temperature protection circuit includes a battery temperature acquisition circuit 2, a battery temperature comparison circuit 3, and an alarm signal output circuit 4, the battery temperature acquisition circuit 2 is used to collect the voltage signal of the corresponding temperature of the single cell in real time, the battery temperature comparison circuit 3 is used to determine whether the voltage signal exceeds a preset threshold voltage, and the alarm signal output circuit 4 is used to generate and send an alarm signal to the controller.

[0038] By applying the technical solution of the present invention, the input end of the battery over-temperature protection circuit is directly connected to the battery module 1 for real-time detection of the temperature information of the single cell battery, and the output end is electrically connected to the vehicle controller. Once an over-temperature state is detected, an alarm signal can be immediately sent to the controller to trigger the subsequent safety processing logic, providing comprehensive over-temperature protection measures for the battery, significantly improving the safety and reliability of electric vehicles and other application fields. The battery temperature acquisition circuit 2 is responsible for collecting the temperature information of each single cell in the battery module, and the battery temperature comparison circuit 3 compares the collected temperature signal with the preset threshold to determine whether the current battery temperature exceeds the safe range. When the battery temperature exceeds the set threshold, an alarm signal is generated and output. The alarm signal is transmitted to the vehicle controller through relay contacts or dry contacts. This solution solves the problem of failure of the vehicle battery management system in the prior art and safety accidents caused by high temperature of the battery.

[0039] It's worth noting that the isolated power supply and battery over-temperature protection circuit are integrated on the same PCB (printed circuit board). This design takes into account circuit compactness and cost-effectiveness. Integration on a single PCB allows for more optimized circuit layout, reduces signal transmission delays and loss, and also facilitates mass production and maintenance. The isolated power supply is powered by an external independent power supply (24V). The independent power supply input is 24V, which is converted to +5V by a DC-DC converter to supply the isolated power supply. The isolated power supply then powers the battery over-temperature protection circuit via a 5V to 5V converter.

[0040] Furthermore, if Figure 2As shown, the battery temperature acquisition circuit 2 includes: a sixth resistor 26 and a temperature sensor 20, wherein the input end of the sixth resistor 26 is connected to the isolated power supply 5; the temperature sensor 20, wherein one end of the temperature sensor 20 is connected to the output end of the sixth resistor 26, and the other end of the temperature sensor 20 is grounded. The temperature sensor 20 and the sixth resistor 26 are connected in series to form a first voltage divider circuit, and the output end of the first voltage divider circuit is connected to the inverting input end of the comparator 10; wherein the first voltage divider circuit is used to generate a voltage signal corresponding to the temperature of the single battery.

[0041] It should be further explained that the temperature sensor 20 is used to collect the temperature of the individual battery cells in real time and convert the temperature value into a voltage signal. To obtain the most accurate battery temperature reading, the temperature sensor should be placed as close to the individual battery cells as possible, or directly attached to the surface of the individual battery cells. Each temperature sensor monitors the temperature of a single individual battery cell or a group of batteries. In this embodiment, one end of a sixth resistor 26 (R26) is connected to the isolated power supply 5 (+5V) and the other end is connected in series with the temperature sensor 20, forming a first voltage divider circuit. The isolated power supply 5 supplies power to the battery temperature acquisition circuit 2. The function of the sixth resistor 26 is to provide a stable voltage reference point for the temperature sensor 20, ensuring that the temperature sensor 20 can still accurately read the temperature even when the battery module 1 is powered off or the power supply is unstable. Because the resistance of the temperature sensor 20 changes with temperature, the voltage divider ratio formed by the sixth resistor 26 and the sensor resistance can indirectly reflect the battery temperature status.

[0042] The temperature sensor 20 is used to collect the temperature of the individual battery cells in real time. In battery overtemperature protection circuits, an NTC (Negative Temperature Coefficient) thermistor is typically used, whose resistance decreases as temperature increases. The temperature sensor converts the detected temperature into a corresponding resistance change, which is inversely proportional to the temperature: the higher the temperature, the lower the resistance. A voltage divider circuit formed with the sixth resistor 26 (R26) converts the resistance change into a voltage signal. This voltage signal can be read by the comparator 10 to determine whether the battery is overheated.

[0043] In this embodiment, the temperature sensor 20 of model CWF4 10KF-B25 / 50=3950-UL4413 is used as an example for description. The temperature range that the temperature sensor 20 can detect is: -150°C to +50°C. Figure 5 As shown in the figure, the corresponding relationship between the resistance value of the temperature sensor and the temperature is given. When applied to the first voltage divider circuit, different temperatures correspond to different resistance values, that is, different acquisition voltages. By collecting the voltage value of the NTC (temperature sensor), the corresponding temperature can be obtained by reverse calculation.

[0044] like Figure 3 As shown, the voltage calculation formula of the first voltage divider circuit is as follows:

[0045]

[0046] Among them, R6 is given as 10k, and the NTC resistance changes with the temperature. Through the change of resistance, different voltage division values ​​are detected, realizing real-time monitoring of temperature.

[0047] Specifically, the battery temperature comparison circuit 3 includes a threshold voltage reference circuit, which includes: a resistor network, which is connected to the non-inverting input terminal of the comparator 10, and the resistor network provides a threshold voltage for the comparator 10, wherein the resistor network includes a first resistor 21, a second resistor 22, a third resistor 23, a fourth resistor 24 and a fifth resistor 25, the first resistor 21 and the fourth resistor 24 are arranged in series on the first circuit, the third resistor 23 and the fifth resistor 25 are arranged in series on the second circuit, the first circuit is connected in parallel with the second circuit, and one end of the second resistor 22 is arranged on the circuit connecting the third resistor 23 and the fifth resistor 25, and the other end of the second resistor 22 is arranged on the circuit connecting the first resistor 21 and the fourth resistor 24, the non-inverting input terminal of the comparator 10 is connected to the first circuit, the inverting input terminal of the comparator 10 is connected to the temperature sensor 20, and the output terminal of the comparator 10 is connected to the input terminal of the alarm signal output circuit 4.

[0048] Specifically, the third resistor 23 is composed of two resistors connected in series, and the two resistors include an eleventh resistor 231 and a twelfth resistor 232; the circuit between the first resistor 21 and the second resistor 22 and the fourth resistor 24 forms a second voltage divider circuit, and the second voltage divider circuit is used to provide a first threshold voltage to the non-inverting input terminal of the comparator 10, and one end of the first resistor 21 and the second resistor 22 is grounded; the circuit between the fifth resistor 25 and the eleventh resistor 231 and the twelfth resistor 232 in series forms a third voltage divider circuit, and the third voltage divider circuit and the second voltage divider circuit are used to provide a second threshold voltage to the non-inverting input terminal.

[0049] In this embodiment, the threshold voltage reference circuit provides a stable threshold voltage for the comparator via a resistor network. This voltage is set as the upper and lower limits of the battery's safe temperature range and is used to determine whether the battery temperature exceeds the safe range. When the voltage signal converted from the battery temperature falls below the first threshold voltage, comparator 10 generates a control signal, triggering the alarm signal output circuit to send an alarm signal to the controller. When the voltage signal converted from the battery temperature rises above the second threshold voltage, the system remains in a normal state. This design ensures the accuracy and responsiveness of the battery overtemperature protection system, enabling timely detection and resolution of battery overtemperature issues, avoiding thermal runaway that could result from battery overheating, and improving the safety of the battery system.

[0050] In a preferred embodiment of the present application, it is assumed that an alarm signal is output when the battery cell temperature reaches 65°C; the alarm signal is released when the battery cell temperature is lower than 55°C. A temperature sensor model CWF4 10KF-B25 / 50=3950-UL4413 is used. According to its specification, its corresponding resistance values ​​at 55°C and 65°C are shown in the following table. The corresponding voltage divider value of the temperature sensor in its Q first voltage divider circuit is also calculated using formula 1-1, as shown in the table:

[0051]

[0052] The voltage divider values ​​corresponding to the intermediate resistance values ​​are selected from the table as the two threshold voltages, namely, a first threshold voltage of 0.863V and a second threshold voltage of 1.149V. That is, when the voltage signal at the inverting input terminal of the comparator 10 is less than 0.863V, the battery over-temperature protection circuit outputs an alarm signal; when the voltage signal at the inverting input terminal of the comparator 10 is greater than 1.149V, the battery over-temperature protection circuit releases the alarm signal output.

[0053] Furthermore, the output end of the comparator 10 is used to generate a control signal. When the voltage signal is less than a first threshold voltage, the control signal is a high level signal. When the voltage signal is greater than a second threshold voltage, the control signal is a low level signal.

[0054] In this embodiment, the core function of comparator 10 is to compare the voltage value converted from the temperature signal (the signal at the inverting input) with a threshold voltage (the signal at the non-inverting input). When the voltage at the inverting input is lower than the lower threshold voltage at the non-inverting input, the comparator outputs a high level, triggering the alarm signal output circuit and indicating that the battery is overheating. Conversely, when the voltage at the inverting input is higher than the higher threshold voltage at the non-inverting input, the comparator outputs a low level, indicating that the battery is not overheating.

[0055] In a preferred embodiment of the present application, when the output signal of the comparator 10 is a low level signal, the second voltage divider circuit is as follows: Figure 6 As shown, the calculation formula of the first threshold voltage is as follows:

[0056]

[0057] Here, R1 represents the first resistor 21 , R2 represents the second resistor 22 , and R4 represents the fourth resistor.

[0058] When the output signal of the comparator 10 is a high level signal, the second voltage divider circuit and the third voltage divider circuit are as follows: Figure 7 As shown, after the star and triangle circuit transformation, the equivalent is as follows Figure 8 As shown:

[0059] Assume (R5+R23)||(R4+R12)=R(2-2);

[0060] Then 5V*R13 / (R13+R)+5V*R / (R13+R)*[R12 / (R12+R4)]=V2(2-3);

[0061] and R12 = (R1R2) / (R1+R2+R3)(2-4);

[0062] R13=(R1R3) / (R1+R2+R3)(2-5);

[0063] R23=(R2R3) / (R1+R2+R3)(2-6);

[0064] Wherein, R1 represents the first resistor 21 , R2 represents the second resistor 22 , R3 represents the third resistor 23 , R4 represents the fourth resistor, and R5 represents the fifth resistor.

[0065] Given R4 = 100k, V1 = 0.863V, V2 = 1.149V, R5 = 10k, R3 = 34k, and then using formulas (2-1) to (2-6) to calculate the values ​​of R1 and R2, the preset second threshold voltage can be obtained by adjusting the resistance values ​​of each resistor.

[0066] Specifically, the alarm signal output circuit 4 includes: a first NMOS tube 41, an isolation optocoupler 43 and a load driving module. The gate of the first NMOS tube 41 is connected to the output end of the comparator 10 to form the input end of the alarm signal output circuit 4. The source of the first NMOS tube 41 is grounded. When the control signal is a high-level signal, the source and drain of the first NMOS tube 41 are turned on. When the control signal is a low-level signal, the source and drain of the first NMOS tube 41 are not turned on; the drain of the first NMOS tube 41 is connected to the second pin of the isolation optocoupler 43, and the first pin of the isolation optocoupler 43 is connected to the isolation power supply 5 through the seventh resistor 27. The seventh resistor 27 (R27) is connected between the first pin of the isolation optocoupler and the isolation power supply to limit the current flowing into the primary side of the optocoupler. When the source and drain of the first NMOS are turned on, the third and fourth pins of the isolation optocoupler 43 are turned on, and the fourth pin is connected to the independent power supply (+5V); the third pin of the isolation optocoupler 43 is connected to the input end of the load driving module, and the output end of the load driving module is electrically connected to the controller to send the control signal to the controller.

[0067] Optionally, when the comparator 10 outputs a high-level signal, the DS channel of the first NMOS tube 41 is turned on, forming a low-impedance path from the D end to the S end. The drain (D) of the first NMOS tube is connected to the second pin of the isolation optocoupler 43. When the DS channel of the first NMOS tube 41 is turned on, the second pin of the isolation optocoupler 43 is "pulled down" to the ground potential (GNDA), which is called a "pull-down operation". In the DS on-state of the first NMOS tube, the collector and emitter of the isolation optocoupler 43 are also triggered to turn on (that is, the third and fourth pins of the isolation optocoupler 43 are turned on), and the +5V voltage is output to the input end of the eighth resistor 28 through the fourth and third pins of the isolation optocoupler, that is, the voltage output by the fourth pin is added to one end of the eighth resistor 28. The electrical signal of the isolation optocoupler 43 is output to the load driving module, and the load driving module converts the working state according to the received signal to drive the relay 50 to work.

[0068] When the comparator 10 outputs a low-level signal, the DS channel of the first NMOS transistor 41 is not turned on, and the alarm signal output circuit 4 does not work.

[0069] In this embodiment, the isolation optocoupler 43 serves as an electrical isolation element between the first NMOS tube 41 and the load driving module, which can prevent electrical interference from the load driving module or the controller end from being transmitted back to the battery temperature acquisition circuit 2 and the battery temperature comparison circuit 3, thereby ensuring the independence of the front-end and rear-end circuits and improving the safety of the system.

[0070] Optionally, a first diode 42 is connected in parallel between the source of the first NMOS tube 41 and the drain of the first NMOS tube 41, and the anode of the first diode 42 is connected to the source of the first NMOS tube 41. The first diode 42 is a parasitic body diode inside the first NMOS tube 41. If the drain voltage is higher than the source voltage, the internal parasitic diode can act as a freewheeling diode to provide a current release path to prevent reverse voltage from being generated between the drain and the source. In this case, the current will flow from the drain to the source through the path of the diode, protecting the first NMOS tube from the impact of reverse voltage. Using the parasitic diode inside the NMOS tube as a freewheeling path can simplify the circuit design and reduce the number of components compared to adding a separate freewheeling diode in the circuit, thereby bringing advantages in cost and space.

[0071] In this embodiment, the third pin of the isolation optocoupler 43 is connected to the input of the load driver module via the eighth resistor 28. The output of the load driver module is electrically connected to the controller, transmitting control signals to the controller. In the circuit between the isolation optocoupler and the load driver module, the eighth resistor (R28) plays a key role in current limiting protection, signal control, matching optocoupler characteristics, and enhancing circuit stability. By properly configuring the eighth resistor, the accurate response and long-term reliability of the battery over-temperature protection circuit can be ensured, thereby providing a safer and more stable over-temperature protection function for the entire battery system.

[0072] Furthermore, the load driving module includes: a first driving module, a second driving module and a relay 50, the first driving module includes a second NMOS tube 44, the gate of the second NMOS tube 44 is connected to the third pin of the isolation optocoupler 43, the source of the second NMOS tube 44 is grounded, and when the control signal is a high-level signal, the source and drain of the second NMOS tube 44 are turned on, and when the control signal is a low-level signal, the source and drain of the second NMOS tube 44 are not turned on; the second driving module includes a first PMOS tube 46, the gate of the first PMOS tube 46 is connected to the third pin of the isolation optocoupler 43, and the source of the second NMOS tube 44 is grounded. The drains of the two NMOS transistors 44 are connected, and the source of the first PMOS transistor 46 is connected to an independent power supply +5V; when the control signal is a high-level signal, the source and drain of the first PMOS transistor 46 are conductive, and when the control signal is a low-level signal, the source and drain of the first PMOS transistor 46 are not conductive; the input end of the relay 50 is connected to the source of the first PMOS transistor 46, and the output end of the relay 50 is electrically connected to the controller. When the control signal is a high-level signal, the normally closed switch of the relay 50 is disconnected, and when the control signal is a low-level signal, the normally closed switch of the relay 50 is closed.

[0073] Optionally, a second diode 45 is connected in parallel between the source and drain of the second NMOS transistor 44, with the anode of the second diode 45 connected to the source of the second NMOS transistor 44. A third diode 47 is connected in parallel between the source and drain of the first PMOS transistor 46, with the anode of the third diode 47 connected to the drain of the first PMOS transistor 46. The source of the first PMOS transistor 46 is connected to an independent power supply (+5V). The second diode is a parasitic body diode within the second NMOS transistor 44, and the third diode is a parasitic body diode within the first PMOS transistor 46. The parasitic diodes naturally provide a freewheeling path for current, protecting the circuit from damage caused by reverse voltage and transient voltage, simplifying circuit design, and improving circuit efficiency and reliability while maintaining cost and space optimization.

[0074] Specifically, a ninth resistor 29 is provided between the third pin of the isolation optocoupler and the gate of the second NMOS transistor 44 , and a tenth resistor 30 is provided between the drain of the first PMOS transistor 46 and the gate of the first PMOS transistor 46 .

[0075] Optionally, a first capacitor 31 is further provided between the source of the second NMOS transistor 44 and the gate of the second NMOS transistor 44, a ninth resistor 29 is provided in parallel with the first capacitor 31, one end of the first capacitor 31 is grounded, and the other end of the first capacitor 31 is connected to the gate of the second NMOS transistor 44. A second capacitor 32 is further provided between the source of the first PMOS transistor 46 and the gate of the first PMOS transistor 46, a tenth resistor 30 is provided in parallel with the second capacitor 32, one end of the second capacitor 32 is connected to the independent power supply (+5V), and the other end of the second capacitor 32 is connected to the gate of the first PMOS transistor 46.

[0076] In this embodiment, the ninth resistor 29 and the first capacitor 31 form a filter circuit, the main function of which is to filter out high-frequency noise in the control signal, ensuring that the signal received by the gate of the second NMOS tube 44 is smooth and stable, and avoiding malfunction caused by noise. Since the capacitor has the ability to store charge, the first capacitor 31 can absorb the instantaneous fluctuation of the gate voltage and prevent the voltage mutation from damaging the second NMOS tube. The grounding setting of the first capacitor 31 helps to improve the anti-interference ability of the circuit. It can quickly release any noise or interference voltage that attempts to enter the gate through the ground path, protecting the circuit from external electromagnetic interference. The combination of the second capacitor 32 and the tenth resistor 30 also constitutes a filter circuit, which has the same main function as the ninth resistor 29 and the first capacitor 31, which is to filter out high-frequency noise in the control signal, ensuring that the signal received by the gate of the first PMOS is smooth and stable, and avoiding malfunction caused by noise.

[0077] Furthermore, the load driving module also includes a fourth diode 48, which is connected in parallel with the relay 50, and the positive electrode of the fourth diode 48 is grounded. The design of the positive electrode of the fourth diode 48 being grounded provides a freewheeling path for the reverse electromotive force generated when the relay 50 coil is de-energized. When the first PMOS tube 46 is turned off, cutting off the current supplied to the relay 50 coil, a reverse electromotive force will be generated in the direction of attempting to maintain the current. At this time, the fourth diode 48 allows current to flow through it from the negative electrode to the positive electrode (i.e., from the coil through the fourth diode 48 to the ground wire), thereby providing a release channel for the magnetic field energy in the coil and preventing the reverse electromotive force from impacting the circuit.

[0078] like Figure 3As shown, the relay 50 has two symmetrical sets of switches, namely 3, 4, 5 and 8, 9, 10. When the control signal is a high-level signal, the normally closed switch of the relay 50 is disconnected. When the control signal is a low-level signal, the normally closed switch of the relay 50 is closed.

[0079] One end of the coil of relay 50 is connected to the drain (D) of first PMOS transistor 46, and the other end is connected to the circuit ground (GND). When the DS channel of first PMOS transistor 46 is open, +5V power flows through first PMOS transistor 46 into the coil of relay 50, generating a magnetic field that drives the relay's armature to move, causing its normally closed contacts (i.e., point 34) to open and its normally open contacts (point 45) to close. This action generates an alarm signal, typically a dry contact output that can be detected by other systems or circuits. When the normally closed contacts of relay 50 open, they effectively disconnect the circuit during normal operation. When the normally open contacts close, an alarm signal output path is formed, which can be connected to the alarm input port of the main control system or other terminal to trigger appropriate safety measures.

[0080] In this embodiment, the main controller uses an I / O port in the controller to detect the switching signal of the relay; under normal circumstances of this protection circuit, the relay outputs a normally closed point, then the I / O detects a low level, indicating a normal state, and the main controller does not perform any processing; if the relay outputs a normally open point (that is, when outputting an alarm signal), the I / O detects a high level, and the main controller outputs corresponding processing measures according to the program.

[0081] Specifically, if Figure 4 As shown, the battery over-temperature protection circuit is provided with multiple battery temperature comparison circuits 3, which are arranged in parallel. The multiple parallel-arranged battery temperature comparison circuits 3 are respectively connected in series with the first NMOS transistor 41 and the isolation optocoupler 43 to form a combination circuit, and the combination circuit is arranged in series with the load driver module. Each battery temperature comparison circuit operates independently. Once any single battery cell is detected to be overheated, it will trigger a corresponding alarm signal. The alarm signal is sent to the load driver module through the combination of the first NMOS transistor and the isolation optocoupler, and ultimately to the controller, triggering the over-temperature protection measure. This design ensures the comprehensiveness and reliability of the battery over-temperature protection system, avoids the failure of the entire battery system due to the overheating of a single battery, and improves the safety and stability of the vehicle. In the battery over-temperature protection circuit, the parallel arrangement of multiple battery temperature comparison circuits not only increases the system's monitoring range, but also enhances the system's redundancy. This includes but is not limited to optimizing the system's monitoring capability and response speed by increasing or decreasing the number of battery temperature comparison circuits under different numbers of single batteries and vehicle operating environments to adapt to a wider range of usage scenarios.

[0082] The battery over-temperature protection system in this embodiment has the following beneficial effects: when the temperature of a single cell reaches the alarm threshold, an alarm signal is immediately output; when the temperature of a single cell drops below the set recovery threshold, the alarm signal is released; this over-temperature protection circuit system serves as a redundant system for the battery system, taking into account the possibility of temperature detection failure of the BMS system, thereby greatly improving the safety of the battery system.

[0083] According to another specific embodiment of the present application, a vehicle is provided. The vehicle has a battery over-temperature protection system, and the battery over-temperature protection system is the battery over-temperature protection system in the above embodiment.

[0084] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figures. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0085] In addition to the above, it should be noted that references to "one embodiment," "another embodiment," "an embodiment," and the like in this specification refer to specific features, structures, or characteristics described in conjunction with that embodiment as included in at least one embodiment generally described in this application. The appearance of the same expression in multiple places in the specification does not necessarily refer to the same embodiment. Furthermore, when a specific feature, structure, or characteristic is described in conjunction with any embodiment, it is intended that such feature, structure, or characteristic, when implemented in conjunction with other embodiments, also falls within the scope of the present invention.

[0086] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0087] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A battery over-temperature protection system, characterized in that: include: A battery module (1), wherein the battery module (1) is composed of a plurality of single batteries; A battery over-temperature protection circuit, wherein the input end of the battery over-temperature protection circuit is connected to the battery module (1), and the output end of the battery over-temperature protection circuit is electrically connected to a controller of the vehicle; an isolated power supply (5), the isolated power supply (5) being connected to the battery over-temperature protection circuit and supplying power to the battery over-temperature protection circuit; The battery over-temperature protection circuit comprises a battery temperature acquisition circuit (2), a battery temperature comparison circuit (3), and an alarm signal output circuit (4); the battery temperature acquisition circuit (2) is used to acquire the voltage signal corresponding to the temperature of the single battery in real time; the battery temperature comparison circuit (3) is used to determine whether the voltage signal exceeds a preset threshold voltage; and the alarm signal output circuit (4) is used to generate and send an alarm signal to the controller.

2. The battery over-temperature protection system according to claim 1, characterized in that: The battery temperature acquisition circuit (2) comprises: a sixth resistor (26), an input end of the sixth resistor (26) being connected to the isolated power supply (5); A temperature sensor (20), one end of the temperature sensor (20) is connected to the output end of the sixth resistor (26), the other end of the temperature sensor (20) is grounded, the temperature sensor (20) and the sixth resistor (26) are connected in series to form a first voltage divider circuit, the output end of the first voltage divider circuit is connected to the inverting input end of the comparator (10), wherein the first voltage divider circuit is used to generate the voltage signal corresponding to the temperature of the single cell.

3. The battery over-temperature protection system according to claim 2, characterized in that: The battery temperature comparison circuit (3) includes a threshold voltage reference circuit, and the threshold voltage reference circuit includes: A resistor network is provided, wherein the resistor network is connected to the non-inverting input terminal of the comparator (10), and the resistor network provides the threshold voltage for the comparator (10), wherein the resistor network includes a first resistor (21), a second resistor (22), a third resistor (23), a fourth resistor (24), and a fifth resistor (25), wherein the first resistor (21) and the fourth resistor (24) are arranged in series on a first circuit, and the third resistor (23) and the fifth resistor (25) are arranged in series on a second circuit, and the first circuit and the second circuit are connected in parallel. The second resistor (22) is connected to the third resistor (23) and the fifth resistor (25), and one end of the second resistor (22) is provided on the circuit connecting the third resistor (23) and the fifth resistor (25), and the other end of the second resistor (22) is provided on the circuit connecting the first resistor (21) and the fourth resistor (24), the non-inverting input end of the comparator (10) is connected to the first circuit, the inverting input end of the comparator (10) is connected to the temperature sensor (20), and the output end of the comparator (10) is connected to the input end of the alarm signal output circuit (4).

4. The battery over-temperature protection system according to claim 3, characterized in that: The third resistor (23) is composed of two resistors, the two resistors including an eleventh resistor (231) and a twelfth resistor (232); A circuit between the first resistor (21), the second resistor (22) and the fourth resistor (24) forms a second voltage divider circuit, the second voltage divider circuit being used to provide a first threshold voltage to the non-inverting input terminal of the comparator (10), and one end of the first resistor (21) and the second resistor (22) being grounded; The circuit between the fifth resistor (25), the eleventh resistor (231) and the twelfth resistor (232) connected in series forms a third voltage divider circuit, and the third voltage divider circuit and the second voltage divider circuit are used to provide a second threshold voltage to the non-inverting input terminal.

5. The battery over-temperature protection system according to claim 4, characterized in that: The output end of the comparator (10) is used to generate a control signal. When the voltage signal is less than the first threshold voltage, the control signal is a high-level signal. When the voltage signal is greater than the second threshold voltage, the control signal is a low-level signal.

6. The battery over-temperature protection system according to claim 5, characterized in that: The alarm signal output circuit (4) comprises: a first NMOS transistor (41), wherein the gate of the first NMOS transistor (41) is connected to the output end of the comparator (10) to form the input end of the alarm signal output circuit (4), the source of the first NMOS transistor (41) is grounded, and when the control signal is a high-level signal, the source and drain of the first NMOS transistor (41) are conductive, and when the control signal is a low-level signal, the source and drain of the first NMOS transistor (41) are not conductive; An isolation optocoupler (43), wherein the drain of the first NMOS tube (41) is connected to the second pin of the isolation optocoupler (43), the first pin of the isolation optocoupler (43) is connected to the isolation power supply (5) via a seventh resistor (27), and when the source and drain of the first NMOS are turned on, the third pin and the fourth pin of the isolation optocoupler (43) are turned on, and the fourth pin is connected to the independent power supply; A load driving module, wherein the third pin of the isolation optical coupler (43) is connected to the input end of the load driving module, and the output end of the load driving module is electrically connected to the controller to send the control signal to the controller.

7. The battery over-temperature protection system according to claim 6, characterized in that: The load driving module includes: A first driving module, the first driving module comprising a second NMOS tube (44), a gate of the second NMOS tube (44) being connected to a third pin of the isolation optical coupler (43), a source of the second NMOS tube (44) being grounded, and when the control signal is a high-level signal, the source and drain of the second NMOS tube (44) being conductive, and when the control signal is a low-level signal, the source and drain of the second NMOS tube (44) being non-conductive; a second driving module, the second driving module comprising a first PMOS tube (46), the gate of the first PMOS tube (46) being connected to the drain of the second NMOS tube (44), the source of the first PMOS tube (46) being connected to the independent power supply, the source and drain of the first PMOS tube (46) being conductive when the control signal is a high-level signal, and the source and drain of the first PMOS tube (46) being non-conductive when the control signal is a low-level signal; A relay (50), wherein an input end of the relay (50) is connected to the source of the first PMOS tube (46), and an output end of the relay (50) is electrically connected to the controller; when the control signal is a high-level signal, the normally closed switch of the relay (50) is disconnected; when the control signal is a low-level signal, the normally closed switch of the relay (50) is closed.

8. The battery over-temperature protection system according to claim 7, characterized in that: A ninth resistor (29) is provided between the third pin of the isolation optical coupler (43) and the gate of the second NMOS transistor (44), and a tenth resistor (30) is provided between the drain of the first PMOS transistor (46) and the gate of the first PMOS transistor (46).

9. The battery over-temperature protection system according to claim 8, characterized in that: The battery over-temperature protection circuit is provided with a plurality of the battery temperature comparison circuits (3), the plurality of the battery temperature comparison circuits (3) are arranged in parallel, the plurality of the battery temperature comparison circuits (3) arranged in parallel are respectively connected in series with the first NMOS tube (41) and the isolation optical coupler (43) to form a combination circuit, and the combination circuit is arranged in series with the load driving module.

10. A vehicle comprising a battery over-temperature protection system, characterized in that: The battery over-temperature protection system is the battery over-temperature protection system according to any one of claims 1 to 9.

Images