Electric vehicle fuse protection circuit

Abstract

The utility model provides a fuse protection circuit of an electric vehicle. The fuse protection circuit comprises an NTC temperature sensor, an MCU, a voltage detection circuit, a current detection circuit, a voltage protection circuit and a voltage control circuit. The working temperature of the fuse is monitored in real time through the NTC temperature sensor, when the temperature exceeds a set threshold value, the circuit can recognize potential overload risks in time, and a load reduction command is sent to a controller of the electric vehicle through various communication modes such as 485, CAN, integrated service digital network and a serial port; the voltage protection and control circuit ensures that the voltage is controlled within a reasonable range, the circuit is turned off when the voltage exceeds a threshold value, elements are prevented from being damaged, the voltage and current values in the circuit are monitored in real time through the voltage detection and current detection circuit, and meanwhile the voltage and current values are uploaded to a cloud server through the 4G module for monitoring and storing historical data. The working state of the motor is automatically adjusted, so that the fault risk is effectively reduced.

Description

Technical Field

[0001] This utility model relates to the field of electric vehicles, and in particular to a fuse protection circuit for electric vehicles. Background Technology

[0002] With the increasing popularity of electric vehicles, their safety and reliability have become increasingly important. During use, motor overload and overheating often lead to circuit failures, affecting overall vehicle performance and potentially causing safety hazards. Traditional protection mechanisms often rely on simple fuses or circuit breakers, which, while providing some protection against current overload, lack real-time monitoring and feedback mechanisms for temperature changes, as well as real-time monitoring of voltage and current, failing to control the circuit to ensure voltage remains within a reasonable range. Summary of the Invention

[0003] In view of this, the present invention aims to propose a fuse protection circuit for electric vehicles, which not only improves the safety of electric vehicles, but also has good compatibility and can be adapted to controllers with various communication protocols.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0005] An electric vehicle fuse protection circuit includes an NTC temperature sensor, an MCU, a voltage detection circuit, a current detection circuit, a voltage protection circuit, and a voltage control circuit. The fuse is electrically connected to both the battery and the NTC temperature sensor. The NTC temperature sensor is electrically connected to the MCU, which monitors the fuse temperature and transmits the temperature data to the MCU chip. The MCU chip processes the data to determine if the upper temperature limit or a set range has been reached. The MCU transmits the data to an external controller of the electric vehicle via a communication module. The battery is electrically connected to the voltage detection circuit, current detection circuit, voltage protection circuit, and voltage control circuit. The circuit is monitored and protected by collecting voltage and current data and implementing overvoltage protection control. The voltage detection circuit, current detection circuit, voltage protection circuit, and voltage control circuit are electrically connected to the MCU. The MCU is electrically connected to a 4G module, which transmits data to a cloud server and stores the data for subsequent fault diagnosis. The MCU is also electrically connected to a horn alarm circuit, providing an alarm function for fuse overheating and serving as a safety warning.

[0006] Furthermore, the fuse and NTC temperature sensor are mounted on an integrated circuit board.

[0007] Furthermore, the voltage protection circuit and voltage control circuit include a PMOS transistor Q11 and a transistor U57. A fuse is connected to the drain of the PMOS transistor Q11. A capacitor C113 is provided between the gate and drain of the PMOS transistor Q11. A resistor R17 and a Zener diode D54 are connected in parallel across the two ends of the C113. The collector of the transistor U57 is connected to the gate of the PMOS transistor Q11 through a resistor R185. The base of the transistor U57 is connected to the VINPUT_C signal output by the MCU through a resistor R177.

[0008] Furthermore, the communication module is one or more of the following: a RS-485 communication module, a CAN communication module, a one-wire communication module, and a serial port. The MCU transmits commands to the external controller of the electric vehicle via the RS-485 communication module, the CAN communication module, the one-wire communication module, and the serial port.

[0009] Furthermore, the MCU includes an AIR32F103RPT6 chip, as well as an 8MHz crystal oscillator circuit, a reset circuit, a download circuit, and a BOOT circuit, which together form the basic circuit.

[0010] Furthermore, the 4G module uses the Air780eg chip, which is a communication module with GNSS and LTE functions, meeting the device positioning requirements and data uploading to the cloud server.

[0011] Compared to existing technologies, the electric vehicle fuse protection circuit described in this utility model has the following advantages: By integrating a fuse, temperature sensor, 4G module, horn alarm circuit, voltage and current detection, voltage protection and control circuit, the circuit monitors the fuse's operating temperature in real time using an NTC temperature sensor. When the temperature exceeds a set threshold, the circuit can promptly identify potential overload risks and send a load reduction command to the electric vehicle's controller via various communication methods (such as 485, CAN, one-wire communication, and serial port). The voltage protection and control circuit ensures that the voltage is controlled within a reasonable range, shutting off the circuit when the threshold is exceeded to prevent component damage. The voltage and current detection circuit monitors the voltage and current values ​​in the circuit in real time and uploads them to a cloud server via the 4G module for monitoring and storage of historical data, automatically adjusting the motor's operating status, thereby effectively reducing the risk of failure. Attached Figure Description

[0012] The accompanying drawings, which form part of this utility model, are used to provide a further understanding of the utility model. The illustrative embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute an undue limitation of the utility model. In the drawings:

[0013] Figure 1 This is a schematic diagram of the principle of this utility model;

[0014] Figure 2 This utility model presents circuit diagrams for four communication methods: 485 communication module, CAN communication module, one-wire communication module, and serial port.

[0015] Figure 3 This is the circuit diagram of the MCU in this utility model;

[0016] Figure 4 This is the circuit diagram of the horn alarm circuit in this utility model;

[0017] Figure 5 This is the circuit diagram of the NTC temperature sensor in this utility model;

[0018] Figure 6 This is a circuit diagram of the voltage protection circuit and voltage control circuit in this utility model;

[0019] Figure 7 This is a circuit diagram of the voltage detection circuit in this utility model;

[0020] Figure 8 This is a circuit diagram of the current detection circuit in this utility model;

[0021] Figure 9 This is the circuit diagram of the 4G module in this utility model. Detailed Implementation

[0022] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0023] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0024] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0025] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0026] like Figure 1 As shown, an electric vehicle fuse protection circuit includes an NTC temperature sensor, an MCU, a voltage detection circuit, a current detection circuit, a voltage protection circuit, and a voltage control circuit. The fuse is electrically connected to both the battery and the NTC temperature sensor. The NTC temperature sensor is also electrically connected to the MCU. The NTC temperature sensor monitors the fuse temperature and transmits the temperature data to the MCU chip. The MCU chip processes the data to determine if the upper temperature limit or a set range has been reached. The MCU transmits the data to an external controller of the electric vehicle via a communication module. The battery is electrically connected to the voltage detection circuit, current detection circuit, voltage protection circuit, and voltage control circuit. The battery monitors and protects the circuit by collecting voltage and current data and implementing overvoltage protection control. The voltage detection circuit, current detection circuit, voltage protection circuit, and voltage control circuit are electrically connected to the MCU. The MCU is electrically connected to a 4G module, which transmits data to a cloud server and stores the data for later troubleshooting. The MCU is also electrically connected to a horn alarm circuit, providing an alarm function for fuse overheating and serving as a safety warning. The fuse and NTC temperature sensor are mounted on an integrated circuit board.

[0027] The fuse is connected in series to the electric vehicle battery voltage output port. An NTC temperature sensor monitors the fuse temperature and transmits the data to the MCU chip. The MCU chip processes the data to determine if the upper temperature limit or set range has been reached, and then transmits commands to an external electric vehicle controller via RS-485, CAN, one-wire communication, or serial port to control or adjust the motor load. By monitoring the fuse temperature, the operating status of the electric vehicle motor is detected, thereby protecting the electric vehicle and controlling the fuse temperature within a normal range, achieving efficient fuse utilization.

[0028] Voltage and current detection circuits are used to monitor the voltage and current values ​​in the circuit in real time. Overvoltage protection circuits ensure that the voltage is controlled within a reasonable range to prevent component damage. A 4G communication module is employed to enhance device positioning capabilities and integrate collected data for uploading to a cloud server, enabling real-time monitoring of the device's data status.

[0029] like Figure 2 As shown, the communication module is one or more of the following: a 485 communication module, a CAN communication module, a one-wire communication module, and a serial port. The MCU transmits commands to the external controller of the electric vehicle through the 485 communication module, the CAN communication module, the one-wire communication module, and the serial port. The 485 communication method uses the SP3485EEN chip. The 485 communication circuit is connected to the MCU, and the VCC pin of the SP3485EEN is connected to a +3.3V power supply. To ensure power supply stability, 10uF (C63) and 100nF (C64) capacitors are connected between VCC and GND to filter out power supply noise. The GND pin of the transceiver is connected to ground. The RO pin is connected to the PB11 pin of the microcontroller, labeled RS485_RXD. The DE (drive enable) and / RE (receive enable) pins are connected and controlled by the MCU microcontroller (labeled RS485_DE_NRE, connected to PB2) to control whether the transceiver is in transmit or receive mode. The DI pin connects to the microcontroller's PB10 pin and is labeled RS485_TXD. A (485A) and B (485B) are the differential data lines for RS-485 communication. These two lines are connected to the external RS-485 bus via the H6 header on the right. A is pulled up with a 10kΩ resistor, and B is pulled down with a 10kΩ resistor. The receiver outputs a high level when the bus is idle or open. A 120Ω resistor is connected between A and B for impedance matching. SMBJ6.5CA (U23, U24, U25) are bidirectional TVS (Transient Voltage Suppressor) diodes, connected across the A / B data lines and ground respectively, to protect the circuit from voltage spikes or surges on the RS-485 bus.

[0030] The CAN bus communication uses the SN65HVD230DR chip. The chip's VCC (pin 3) is connected to a 3.3V power supply and grounded via a 100nF capacitor for filtering. Pins 1 and 4 are connected to pins 44 and 45 of the MCU chip, which are the CAN bus input / output ports. A pull-down switch on the RS pin indicates high-speed mode. Pins 6 and 7 are connected to the low-level and high-level CAN buses, respectively. A 120Ω resistor is connected between the high and low-level CAN buses for impedance matching, effectively suppressing signal reflection.

[0031] The One-Line Communication uses the Q3 transistor as a switch control, allowing single-line protocol communication.

[0032] ONEWRITE pin: This is the MCU control pin. The high and low levels output by the ONEWRITE pin control the conduction or cutoff of transistor Q3, thereby controlling the level of X_ONEWRITE.

[0033] R101 (10kΩ) is a current-limiting resistor connected between the control signal ONEWRITE and the base of Q3 to limit the current entering the base of Q3, thereby protecting the transistor from excessive current.

[0034] Q3 (SS8050) is an NPN transistor used as a switch. When ONEWRITE is high, Q3 is turned on, and X_ONEWRITE outputs a low level; when ONEWRITE is low, Q3 is turned off, and X_ONEWRITE outputs a high level.

[0035] R102 (100kΩ) is a pull-down resistor used to pull the voltage down to 0V when there is no input signal at the base of transistor Q3, ensuring that Q3 remains in the off state.

[0036] C82 (10nF) is a filter capacitor used to filter out high-frequency noise in the signal, ensuring the stability of the circuit and the integrity of the signal.

[0037] The H7 socket is used as an interface for connecting external devices. The X_ONEWRITE signal serves as a communication line, enabling communication with external devices via the One-Line Communicator protocol.

[0038] Working principle summary: When the ONEWRITE input is high, Q3 is turned on, and X_ONEWRITE outputs a low level. When ONEWRITE is low, Q3 is turned off, and X_ONEWRITE is in a high-level state. Capacitor C82 acts as a filter, while resistors R101 and R102 are used for control and signal stabilization.

[0039] Serial communication can be achieved by connecting the MCU's serial port pins 42 and 43 to an external device via a connector.

[0040] Figure 3 The MCU microcontroller unit is model AIR32F103RPT6. A crystal oscillator is connected between pins 5 and 6 of the MCU microcontroller unit, and pins 5 and 6 are grounded through capacitors C56 and C57 respectively, forming a clock circuit. Pin 7 of the MCU microcontroller unit is connected to the reset circuit. Pins 1, 32, 48, and 64 of the MCU microcontroller unit are connected to a 3.3V power supply. Pins 28, 29, and 30 of the MCU microcontroller unit are connected to the input pins of the 485 chip. Pins 44 and 45 of the MCU microcontroller unit are connected to the input pins of the CAN transceiver chip. Pin 23 of the MCU microcontroller unit is connected to a one-line communication interface. Pins 42 and 43 of the MCU microcontroller unit are connected to pins 1 and 2 of the serial communication connector. Pins 15 and 16 of the MCU microcontroller unit are connected to voltage and current detection ports. Pin 20 of the MCU microcontroller unit is connected to the overvoltage protection circuit control interface. Pins 46 and 49 of the MCU microcontroller unit are connected to the download port.

[0041] like Figure 4 The diagram shows the horn alarm circuit.

[0042] BEEP pin: This is the control signal input terminal. When the BEEP pin is high, current flows through resistor R38 to the base of Q4, turning on Q4 and driving the buzzer to sound.

[0043] R38 (1kΩ) and R39 (10kΩ): R38 is used to limit the current entering the base of Q4 to prevent excessive current from damaging the transistor. R39 is a pull-down resistor used to ensure that the base potential of Q4 is pulled low when the BEEP pin is low, keeping Q4 in the off state.

[0044] Q4: This is an NPN transistor used as a switching element. When the BEEP pin is high, Q4 is turned on, and current flows from the +3.3V power supply through R108 to the buzzer, then to the collector of Q4, and finally to ground, driving the buzzer to sound.

[0045] Buzzer (BUZZER2): This is the output component of the circuit. When Q4 is turned on, current flows through the buzzer, causing it to vibrate and produce sound. Select an appropriate resistor value R108 according to the actual parameters and model of the buzzer.

[0046] D7 (DSK34): This is a freewheeling diode used to protect transistor Q4. When Q4 is off, a reverse voltage (induced electromotive force) is generated due to the inductive effect of the buzzer. D7 can release the reverse current to prevent damage to the transistor.

[0047] C37 (100nF): This is a decoupling capacitor used to filter out high-frequency noise on the power supply and ensure stable circuit operation.

[0048] Working principle summary: When the BEEP pin is high, Q4 conducts, current flows through the buzzer, and the buzzer sounds. When the BEEP pin is low, Q4 is off, and the buzzer stops sounding. D7 provides protection against reverse voltage damage to Q4, while C37 is used for power supply decoupling.

[0049] like Figure 5 The diagram shows an NTC temperature sensor circuit that transmits temperature signals to the MCU microcontroller unit via an external NTC.

[0050] like Figure 6The diagram shows a voltage protection circuit and a voltage control circuit, including a PMOS transistor Q11 and a transistor U57. A fuse is connected to the drain of the PMOS transistor Q11. A capacitor C113 is provided between the gate and drain of the PMOS transistor Q11. A resistor R17 and a Zener diode D54 are connected in parallel across the two ends of the C113. The collector of the transistor U57 is connected to the gate of the PMOS transistor Q11 through a resistor R185. The base of the transistor U57 is connected to the VINPUT_C signal output by the MCU through a resistor R177.

[0051] The fuse is connected to the circuit, and its temperature is detected by an NTC temperature sensor. The input voltage VINPUT is stabilized within a fixed range by a Zener diode D54.

[0052] When an excessively high voltage is detected, the MCU controls the VINPUT_C port to be low. Transistor U57 is not turned on, which is equivalent to an open circuit. The Vgs of PMOS transistor Q11 is 0, so the PMOS transistor is also not turned on, and VOUTPUT has no power.

[0053] When the detected voltage is within the normal range, the MCU controls VINPUT_C to be high, which turns on transistor U57. As a result, Vgs of PMOS transistor Q11 is less than 0, and the PMOS transistor is turned on. In other words, VINPUT and VOUTPUT are connected, and VOUTPUT is powered.

[0054] Figure 7 The voltage detection circuit uses resistors R183 and R30 to divide the voltage to obtain the node voltage. The output voltage is then connected to the MCU's ADC for data processing to calculate the voltage value in the original circuit.

[0055] Figure 8 This is a current detection circuit; current flows through... Figure 6 The 1KΩ resistor between OUT_1 and VOUTPUT is connected in series with the load in the subsequent circuit. The voltage difference across the resistor is converted into a 0-3.3V voltage by the LM358B op-amp. This voltage is then fed into the MCU's ADC for data processing to calculate the current value in the original circuit.

[0056] Figure 9This 4G module utilizes its GPS and 4G communication functions to transmit data collected by the sensor board to the cloud server. The circuit employs the Air780eg chip, an LTE Cat 1+GNSS positioning and wireless communication module designed based on the EC618 platform. U49 in the diagram is a JW5033S DC-DC power supply chip. It supports 4G long-range wireless transmission technology and BeiDou / GPS dual-mode satellite positioning. Pins 17 and 18 of the chip are the receive and transmit serial ports. Pins 59, 60, and 61 of the chip connect to the USB interface, which can be used for AT command transmission, data transfer, software debugging, and software upgrades. U40 is the SIM card slot, connected to the chip via pins 11, 12, 13, and 14. The chip connects to the 4G antenna via pins 34 and 35, thus completing the 4G communication function and connecting to the cloud server. Pins 1 and 2 of the chip connect to the GPS antenna to complete the device positioning function.

[0057] This invention connects a fuse to the battery output voltage and monitors the fuse temperature via an NTC transmitter. The temperature data is transmitted to an MCU chip, which then processes the data to determine if the upper temperature limit or relevant setting range has been reached. Commands are then transmitted to an external electric vehicle controller via RS-485, CAN, one-wire communication, or serial port to adjust the motor's operating state, thereby reducing the fuse temperature and providing protection. An overvoltage protection circuit ensures the voltage is controlled within a reasonable range to prevent component damage. Voltage and current detection modules monitor the voltage and current values ​​in the circuit in real time. Simultaneously, a 4G module uploads data to a cloud server for storage, and GPS positioning allows for device location tracking. This provides more convenient maintenance and troubleshooting for subsequent product malfunctions.

[0058] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An electric vehicle fuse protection circuit, characterized by: The application relates to an electric vehicle controller, which comprises an NTC temperature sensor, an MCU, a voltage detection circuit, a current detection circuit, a voltage protection circuit and a voltage control circuit, a fuse is electrically connected with a battery and the NTC temperature sensor respectively, the NTC temperature sensor is electrically connected with the MCU, the MCU transmits data to an external controller of the electric vehicle through a communication module, the battery is electrically connected with the voltage detection circuit, the current detection circuit, the voltage protection circuit and the voltage control circuit respectively, the voltage detection circuit, the current detection circuit, the voltage protection circuit and the voltage control circuit are electrically connected with the MCU, the MCU is electrically connected with a 4G module, and the MCU is further electrically connected with a horn alarm circuit.

2. An electric vehicle fuse protection circuit according to claim 1, wherein: The fuse and the NTC temperature sensor are arranged on an integrated circuit board.

3. The fuse protection circuit for an electric vehicle according to claim 1 or 2, characterized by: The voltage protection circuit and the voltage control circuit comprise a PMOS tube Q11, a triode U57, the fuse is connected with the drain of the PMOS tube Q11, a capacitor C113 is arranged between the gate and the drain of the PMOS tube Q11, resistors R17 and a stabilizing diode D54 are connected in parallel at two ends of the capacitor C113, the collector of the triode U57 is connected with the gate of the PMOS tube Q11 through a resistor R185, and the base of the triode U57 is connected with a VINPUT_C signal output by the MCU through a resistor R177.

4. The fuse protection circuit for an electric vehicle of claim 3, wherein: The communication module is one or more of a 485 communication module, a CAN communication module, a one-wire communication and a serial port.

5. The fuse protection circuit for an electric vehicle of claim 1, wherein: The MCU comprises an AIR32F103RPT6 chip, and further comprises an 8MHZ crystal oscillation circuit, a reset circuit, a downloading circuit and a BOOT circuit.

6. An electric vehicle fuse protection circuit according to claim 1, wherein: The 4G module adopts an Air780eg chip.

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