Protection circuit and device of electric vehicle controller

Abstract

The utility model provides a protection circuit and device of an electric vehicle controller, and relates to the field of electric vehicle accessories. The circuit comprises a rectification unit, a first step-down unit, a second step-down unit, an MCU controller unit, a PWM-to-DAC unit and an electronic load unit which are sequentially connected in series, and also comprises a turning handle signal detection unit and a battery voltage detection unit which are respectively connected with the MCU controller unit, the output end of the rectification unit is connected with the electronic load unit. The output end of the first voltage reduction unit is connected with the electronic load unit. Wherein the input end of the rectifying unit is used for being connected with a three-phase line of a motor of the electric vehicle, the input end of the rotating handle signal detection unit is used for being connected with a rotating handle signal line of the electric vehicle, and the battery voltage detection unit is used for being connected with the output end of a power supply battery of the electric vehicle. The circuit can solve the problem of dredging the reverse charging current of the motor after the battery protection board is turned off, prevents the MOS tube of the controller from overvoltage breakdown, and protects the core device of the controller.

Description

A protection circuit and device for an electric vehicle controller Technical Field

[0001] This application relates to the field of electric vehicle accessories, and more specifically, to a protection circuit and device for an electric vehicle controller. Background Technology

[0002] With the increasing popularity of electric vehicles, the safety and reliability of these vehicles under complex operating conditions have become key technological challenges. Especially in long downhill scenarios, if the energy generated by the reverse charging of the motor cannot be effectively channeled, it can easily lead to overvoltage breakdown of core components of the controller (such as MOSFETs), causing system failures or even safety hazards.

[0003] In developing this application, the inventors discovered that the controller is extremely prone to burnout in long downhill scenarios because the industry currently relies heavily on hardware protection mechanisms of battery protection boards to address reverse charging issues. Specifically, when motor reverse charging causes the battery voltage to exceed a threshold, the protection board's shutdown protection mechanism is triggered. However, during this period, the continuous reverse charging current generated by the motor loses an effective channel and cannot be released through the battery circuit, instead directly impacting the controller's MOSFET, causing a risk of instantaneous high-voltage breakdown.

[0004] Therefore, there is an urgent need for a circuit that can still effectively protect the electric vehicle controller circuit when the protection shutdown mechanism is triggered to address this problem. Summary of the Invention

[0005] To address the aforementioned issues, this application provides a protection circuit and device for an electric vehicle controller, which can resolve the issue of mitigating the reverse charging current of the motor after the battery protection board is turned off, prevent overvoltage breakdown of the controller's MOSFET, protect the controller's core components, and improve the controller's lifespan and vehicle driving safety.

[0006] This application is implemented as follows:

[0007] In a first aspect, this application provides a protection circuit for an electric vehicle controller, comprising a rectifier unit, a first buck unit, a second buck unit, an MCU controller unit, a PWM to DAC unit, and an electronic load unit connected in series. It also includes a throttle signal detection unit and a battery voltage detection unit, respectively connected to the MCU controller unit. The output terminal of the rectifier unit is connected to the electronic load unit, and the output terminal of the first buck unit is also connected to the electronic load unit. The input terminal of the rectifier unit is connected to the three-phase lines of the electric vehicle motor, the input terminal of the throttle signal detection unit is connected to the throttle signal line of the electric vehicle, and the battery voltage detection unit is connected to the output terminal of the electric vehicle's power supply battery.

[0008] In some implementations, the rectifier unit includes diodes D3, D4, D5, D6, D7, D8, and capacitor C5. The anodes of diodes D3, D4, and D5 are connected to the first terminal of capacitor C5; the cathodes of diodes D6, D7, and D8 are connected to the second terminal of capacitor C5; the anode of diode D8 is connected to the cathode of diode D3; the anode of diode D7 is connected to the cathode of diode D4; the anode of diode D6 is connected to the cathode of diode D5; the anode of diode D8 is connected to the U-phase line of the electric vehicle motor; the anode of diode D7 is connected to the V-phase line of the electric vehicle motor; and the anode of diode D6 is connected to the W-phase line of the electric vehicle motor.

[0009] In some implementations, the first step-down unit includes: a DC-DC step-down chip U2, a diode D9, resistors R25, R24, and R23, inductors L3 and L4, and capacitors C6, C7, and C9. Specifically, the VIN pin of DC-DC step-down chip U2 is connected to the cathode of diode D6 through inductor L3; the VIN pin of DC-DC step-down chip U2 is connected to the GND pin of DC-DC step-down chip U2 through capacitor C6; the GND pin of DC-DC step-down chip U2 is connected to the FB pin of DC-DC step-down chip U2 through resistor R25; the FB pin of DC-DC step-down chip U2 is connected to the VS pin of DC-DC step-down chip U2 through resistor R24 ​​and inductor L4; the IS pin of DC-DC step-down chip U2 is connected to the VS pin of DC-DC step-down chip U2 through resistor R23; the VB pin of DC-DC step-down chip U2 is connected to the VC pin of DC-DC step-down chip U2 through capacitor C7; the cathode of diode D9 is connected to the VS pin of DC-DC step-down chip U2; and the cathode of diode D9 is connected to the VS pin of DC-DC step-down chip U2 through capacitor C9 and inductor L4.

[0010] In some implementations, the second step-down unit includes: a linear regulator chip U5, an inductor L5, a capacitor C8, a capacitor C10, and a capacitor C11. Specifically, the VIN pin of the linear regulator chip U5 is connected to the VS pin of the DC-DC step-down chip U2 via the inductor L4. Capacitors C8, C10, and C9 are connected in parallel in pairs. The VIN pin of the linear regulator chip U5 is connected to the GND pin of the linear regulator chip U5 via capacitor C10 and inductor L5. The VOUT pin of the linear regulator chip U5 is connected to the GND pin of the linear regulator chip U5 via capacitor C11.

[0011] In some implementations, the MCU controller unit includes: a processor chip U4 of model CW32F003E4P7, a capacitor C12, a resistor R26, a light-emitting diode LED1, and a terminal block H2. Specifically, pin VSS of processor chip U4 is connected to pin VDD of processor chip U4 via capacitor C12; pin VDD of processor chip U4 is connected to pin VOUT of linear regulator chip U5; terminal 1 of terminal block H2 is connected to pin VDD of processor chip U4; terminal 2 of terminal block H2 is connected to pin PA02 of processor chip U4; terminal 3 of terminal block H2 is connected to pin PA05 of processor chip U4; pin VDD of processor chip U4 is connected to the anode of light-emitting diode LED1 via resistor R26; and the cathode of light-emitting diode LED1 is connected to pin PB05 of processor chip U4.

[0012] In some implementations, the PWM to DAC unit includes: capacitor C13, capacitor C14, capacitor C15, resistor R27, and resistor R28. One end of capacitor C13 is connected to pin PB02 of processor chip U4, and the other end is grounded through resistors R27, R28, and capacitor C15. The common terminal of resistors R27 and R28 is grounded through capacitor C14.

[0013] In some implementations, the electronic load unit includes: comparator U1.1, comparator U3.2, transistor Q2, transistor Q3, transistor Q4, transistor Q5, MOSFET Q1, MOSFET Q6, inductor L1, inductor L2, resistor R1, resistor R9, resistor R7, resistor R8, resistor R5, resistor R6, resistor R4, resistor R3, resistor R2, resistor R22, resistor R21, resistor R20, resistor R18, resistor R19, resistor R16, resistor R17, resistor R14, resistor R15, capacitor C10, capacitor C18, and capacitor C4. In this circuit, the non-inverting input of comparator U1.1 is connected to the common terminal of resistor R28 and capacitor C15. The non-inverting input of comparator U1.1 is connected to its output via a parallel connection of capacitor C18 and resistor R1. The power input of comparator U1.1 is connected to pin VS of DC-DC step-down chip U2 via inductor L4. The power input of comparator U1.1 is grounded via capacitor C10. The inverting input of comparator U1.1 is grounded via resistors R9 and R2. The output of comparator U1.1 is connected to the base of transistor Q2. The base of transistor Q2 is connected to its emitter via resistor R8. The base of transistor Q2 is connected to pin PB03 of processor chip U4 through resistor R7. The collector of transistor Q2 is connected to the base of transistor Q3 through resistor R4. The base of transistor Q3 is connected to the emitter of transistor Q3 through resistor R6. The emitter of transistor Q3 is connected to pin VS of DC-DC step-down chip U2 through inductor L4. The collector of transistor Q3 is connected to the gate of MOSFET Q1 through resistor R4. The gate of MOSFET Q1 is connected to the source of MOSFET Q1 through resistor R3. The drain of MOSFET Q1 is connected to the cathode of diode D6. The drain of MOSFET Q1 is grounded through resistor R2 and inductor L1.The non-inverting input of comparator U3.2 is connected to the common terminal of resistor R28 and capacitor C15. The non-inverting input of comparator U3.2 is connected to its output through a parallel connection of capacitor C15 and resistor R4. The inverting input of comparator U3.2 is grounded through resistors R14 and R22. The output of comparator U3.2 is connected to the base of transistor Q5. The base of transistor Q5 is connected to its emitter through resistor R16. The base of transistor Q5 is connected to pin PB03 of processor chip U4 through resistor R17. The collector of transistor Q5 is connected to the base of transistor Q4 through resistor R19. The base of transistor Q4 is connected to the emitter of transistor Q4 through resistor R18. The emitter of transistor Q4 is connected to pin VS of DC-DC step-down chip U2 through inductor L4. The collector of transistor Q4 is connected to the gate of MOSFET Q6 through resistor R20. The gate of MOSFET Q6 is connected to the source of MOSFET Q6 through resistor R21. The drain of MOSFET Q6 is connected to the cathode of diode D6. The drain of MOSFET Q6 is grounded through resistor R22 and inductor L2.

[0014] In some implementations, the throttle signal detection unit includes: a terminal block J4, a diode D10, a capacitor C17, a capacitor C16, a resistor R29, a resistor R30, and a resistor R31. Terminal block J4 is connected to the throttle signal line of the electric vehicle. Terminal 2 of terminal block J4 is connected to terminal 3 of terminal block J4 via resistor R30. Terminal 2 of terminal block J4 is connected to terminal 3 of terminal block J4 via resistor R29 and capacitor C17. The common terminal of resistor R29 and capacitor C17 is connected to pin PA06 of processor chip U4. Terminal 1 of terminal block J4 is grounded via capacitor C16. Terminal 1 of terminal block J4 is connected to pin VOUT of linear regulator chip U5 via resistor R31. The anode of diode D10 is connected to pin VOUT of linear regulator chip U5, and the cathode of diode D10 is connected to terminal 1 of terminal block J4.

[0015] In some implementations, the battery voltage detection unit includes: capacitor C2, resistor R32, resistor R33, resistor R34, and resistor R35. One end of resistor R35 is grounded and connected to the negative terminal of the electric vehicle's battery, while the other end is connected to the positive terminal of the electric vehicle's battery via resistors R34, R33, and R32 in sequence. Capacitor C2 and resistor R35 are connected in parallel, and the common terminal of resistors R35 and R34 is connected to pin PA04 of the processor chip U4.

[0016] Secondly, this application provides a protection device for an electric vehicle controller, which includes a protection circuit for any of the electric vehicle controllers described in the first aspect.

[0017] Compared with the prior art, this application has at least the following advantages or beneficial effects:

[0018] This application provides a protection circuit for an electric vehicle controller. The circuit rectifies the AC reverse-charging current from the three-phase motor lines into DC power via a rectifier unit, and then directly connects it to the electronic load unit, forming a discharge channel independent of the battery circuit. Furthermore, the rectified high-voltage DC power is progressively stepped down by a first step-down unit (exemplarily a BUCK structure) and a second step-down unit (exemplarily an LDO structure) to provide a stable power supply to the MCU controller and electronic load, ensuring continued operation even when the lithium battery protection board is turned off. That is, the reverse-charging current forms a closed loop from the three-phase motor lines → rectifier unit → electronic load unit → ground, preventing energy accumulation at the MOSFET terminals and utilizing the reverse-charging energy to power its own circuit (without relying on the battery), ensuring the system continues to operate during the protection board shutdown period, achieving "uninterrupted protection even when power is off."

[0019] Meanwhile, by collecting parameters from both the throttle signal detection unit and the battery voltage detection unit, erroneous actions during normal deceleration or short downhill periods can be reduced.

[0020] In addition, the PWM to DAC unit converts the digital PWM signal output by the MCU into an analog voltage signal, which linearly controls the on-resistance of the electronic load. As the MCU monitors the discharge circuit current and voltage in real time and dynamically adjusts the PWM duty cycle, it can improve the matching between the discharge power and the reverse charging energy.

[0021] Furthermore, the throttle signal detection unit is connected in parallel with the original throttle cable, and the battery voltage detection unit is connected in parallel with the original battery terminal, so as not to interfere with the original vehicle signal transmission. Compared with the traditional solution of modifying the original vehicle circuit (such as adding a relay or disconnecting the original wiring), maintenance costs can be reduced. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 is a schematic diagram of the structure of a protection circuit of an electric vehicle controller according to an embodiment of this application;

[0024] Figure 2 is a circuit diagram of the rectifier unit in one embodiment of the protection circuit of an electric vehicle controller according to this application;

[0025] Figure 3 is a circuit diagram of the first step-down unit and the second step-down unit in one embodiment of the protection circuit of an electric vehicle controller according to this application;

[0026] Figure 4 is a circuit diagram of the MCU controller unit in one embodiment of the protection circuit of an electric vehicle controller according to this application;

[0027] Figure 5 is a circuit diagram of a PWM to DAC unit in one embodiment of the protection circuit of an electric vehicle controller according to this application;

[0028] Figure 6 is a circuit diagram of the electronic load unit in one embodiment of the protection circuit of an electric vehicle controller according to this application;

[0029] Figure 7 is a circuit diagram of the throttle signal detection unit in one embodiment of the protection circuit of an electric vehicle controller according to this application;

[0030] Figure 8 is a circuit diagram of the battery voltage detection unit in one embodiment of the protection circuit of an electric vehicle controller according to this application.

[0031] Icons: 11. Rectifier unit; 12. First buck unit; 13. Second buck unit; 14. MCU controller unit; 15. PWM to DAC unit; 16. Electronic load unit; 17. Throttle signal detection unit; 18. Battery voltage detection unit. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. In this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0033] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0034] Application Overview

[0035] In the scenario of long downhill driving for new energy electric vehicles, the inventors discovered through analysis of numerous failure cases that existing technologies rely on the passive shutdown mechanism of the lithium battery protection board. While this can prevent battery overvoltage, it transfers the reverse charging current to the controller MOSFET, creating a "protection blind spot." Specifically, when the protection board cuts off the charging path, the high-voltage reverse charging current generated by the motor due to inertia has nowhere to be released, directly impacting the MOSFET and causing it to break down.

[0036] To address the aforementioned technical issues, this application provides a protection circuit for an electric vehicle controller. Without altering the original vehicle circuitry, it achieves "bypass protection" by connecting signal acquisition and electronic load in parallel. This design fundamentally resolves the contradiction between "protection board shutdown" and "controller safety" in long downhill scenarios. By actively diverting voltage instead of passively bearing the load, it effectively prevents overvoltage breakdown of the controller's MOS transistor in long downhill scenarios.

[0037] After introducing the basic principles of this application, various non-limiting embodiments of this application will be described in detail below with reference to the accompanying drawings. Unless otherwise specified, the various embodiments and features described below can be combined with each other.

[0038] Exemplary circuits and devices

[0039] Referring to Figure 1, the protection circuit of this electric vehicle controller includes a rectifier unit 11, a first step-down unit 12, a second step-down unit 13, an MCU controller unit 14, a PWM to DAC unit 15, and an electronic load unit 16 connected in series. It also includes a throttle signal detection unit 17 and a battery voltage detection unit 18, both connected to the MCU controller unit 14. The output of the rectifier unit 11 is connected to the electronic load unit 16, and the output of the first step-down unit 12 is also connected to the electronic load unit 16. The input of the rectifier unit 11 is connected to the three-phase lines of the electric vehicle motor, the input of the throttle signal detection unit 17 is connected to the throttle signal line of the electric vehicle, and the battery voltage detection unit 18 is connected to the output of the electric vehicle's power supply battery.

[0040] In the above embodiment, energy protection is achieved through the electronic load unit 16, transforming the passive absorption of reverse charging energy into active control. This breaks the energy island effect after the battery protection board is turned off and establishes an independent discharge channel (motor three-phase lines → rectifier unit 11 → electronic load unit 16). Simultaneously, this circuit combines human-machine interaction signals (signals detected by the throttle signal detection unit 17), battery status signals (signals detected by the battery voltage detection unit 18), and fault causes (reverse charging energy), providing precise protection for the electric vehicle controller. For example, in a long downhill test with an 8% gradient and a vehicle speed of 40 km / h, the controller failure rate decreased from 32% in the traditional solution to 0.5%, effectively protecting the electric vehicle.

[0041] The following section will provide a detailed explanation of each unit.

[0042] For the rectifier unit 11, the input terminal of the rectifier unit 11 is connected to the three-phase lines of the electric vehicle motor. When the motor rotates, it generates a three-phase AC voltage. The rectifier unit 11 contains multiple rectifier components such as diodes. Utilizing the unidirectional conductivity of the diodes, the three-phase AC voltage is converted into a pulsating DC voltage. Then, through a filter circuit (usually a capacitor filter), the pulsating DC voltage is smoothed into a more stable DC voltage, namely the first DC voltage, and output to the subsequent electronic load unit 16 and the first step-down unit 12.

[0043] The rectifier unit 11 converts the AC power generated by the motor into DC power, providing a stable power input for other units in the entire protection circuit and ensuring that each unit can operate normally. Furthermore, the electric vehicle motor enters generator mode under conditions such as long downhill slopes, generating a reverse charging current. The rectifier unit 11 can promptly and effectively handle this reverse charging AC power, preventing damage to other circuit components and ensuring the safety and stability of the circuit.

[0044] For the first buck unit 12, its input terminal receives the first DC voltage output from the rectifier unit 11, and the first DC voltage is stepped down to a second voltage (typically 12V) through an internal buck circuit (such as a linear regulator circuit or a switching power supply buck circuit). The second buck unit 13 further steps down the second voltage output from the first buck unit 12 to a third voltage (typically 3.3V) to meet the needs of electronic components such as the MCU controller unit 14, which have specific requirements for operating voltage.

[0045] In the electric vehicle controller protection circuit, different electronic components have different operating voltage requirements. The step-down unit can reduce the high voltage output by the rectifier unit 11 to a suitable level in stages, ensuring that each component operates reliably under a stable voltage environment and avoiding damage to components due to excessively high or low voltage. Through the two-stage reasonable step-down design of the first step-down unit 12 and the second step-down unit 13, energy loss during voltage conversion is reduced, the energy utilization efficiency of the entire protection circuit is improved, and it helps to extend the driving range of the electric vehicle.

[0046] For the throttle signal detection unit 17, its input terminal is connected to the throttle signal line of the electric vehicle. The throttle outputs an analog voltage signal by changing its internal resistance, which reflects the user's intention to control the speed of the electric vehicle. The throttle signal detection unit 17 contains a signal conditioning circuit (such as an amplifier circuit and a filter circuit) to amplify and filter the acquired analog voltage signal, remove noise and interference, and then convert the processed analog voltage signal into a digital signal, which is transmitted to the MCU controller unit 14.

[0047] The real-time and accurate acquisition of the throttle signal enables the MCU controller unit 14 to understand the user's speed control requirements for the electric vehicle, thereby making more reasonable protection decisions based on actual operating conditions. For example, when going downhill, if the user releases the throttle, the throttle signal will change. The MCU controller unit 14 can use this signal to determine that the vehicle may be going downhill and prepare for protection in advance. The coordination of multiple signals from the throttle signal detection unit 17 and the battery voltage detection unit 18 provides the MCU controller unit 14 with more comprehensive vehicle operating information, improving the intelligence level of the protection circuit and enabling it to better adapt to complex and changing driving environments.

[0048] The battery voltage detection unit 18 is connected to the output terminal of the electric vehicle's power supply battery. It acquires the battery's supply voltage signal in real time through its internal voltage detection circuit (such as a voltage divider resistor network and an analog-to-digital converter), and transmits this signal to the MCU controller unit 14. The voltage detection circuit divides the battery's high voltage according to a certain ratio, converting it into a low voltage signal suitable for processing by the analog-to-digital converter. The analog-to-digital converter then converts the analog voltage signal into a digital signal for analysis and processing by the MCU controller unit 14.

[0049] The system continuously monitors the battery's supply voltage, providing real-time battery status information to the MCU controller unit 14. When the battery voltage changes due to factors such as motor reverse charging, the MCU controller unit 14 can promptly acquire this information, determine whether the battery is within its normal operating range, and prevent damage to the controller due to abnormal battery voltage. The battery voltage detection unit 18, combined with the signals collected by the throttle signal detection unit 17, enables the MCU controller unit 14 to more accurately determine the vehicle's operating conditions, thereby formulating more reasonable protection strategies. For example, when a rise in battery voltage is detected and the throttle signal indicates that the user has released the throttle, it can be determined that the vehicle is in a long downhill reverse charging state, and corresponding protective measures can be taken.

[0050] For the MCU controller unit 14, it is the core control component of the entire protection circuit. It receives digital signals (analog throttle voltage information) transmitted from the throttle signal detection unit 17 and digital signals (battery power supply voltage signal) transmitted from the battery voltage detection unit 18. Based on a preset intelligent algorithm and program, it performs comprehensive analysis and processing on these signals (this can be achieved by directly comparing these signals with corresponding thresholds to determine the vehicle's operating status; that is, a conventional threshold judgment method can be used). By determining the vehicle's operating status (such as whether it is in a long downhill, rapid acceleration, or sudden braking condition), the MCU controller unit 14 outputs a corresponding pulse width modulation (PWM) signal.

[0051] The MCU controller unit 14 can intelligently analyze and judge multi-dimensional signals to formulate the most suitable protection strategy for the current operating conditions. Compared with the traditional single-parameter protection mechanism, the intelligent decision-making capability of the MCU controller unit 14 greatly improves the accuracy and reliability of the protection circuit, effectively avoiding false judgments and missed judgments. Furthermore, facing the complex and ever-changing operating conditions during the operation of electric vehicles, the MCU controller unit 14 can adjust the duty cycle of the PWM signal in real time, thereby precisely controlling the working state of the electronic load unit 16, realizing dynamic adjustment of the controller protection, and ensuring that the controller can operate safely and stably under various operating conditions.

[0052] For the PWM to DAC unit 15, it receives the PWM signal output by the MCU controller unit 14. The PWM signal is a digital signal with adjustable pulse width, and its duty cycle reflects the average level of the signal. The PWM to DAC unit 15 internally includes filtering circuits (such as RC filter circuits) to convert the PWM signal into an analog control signal. The filtering circuit integrates the PWM signal to remove high-frequency components, obtaining a DC analog voltage signal proportional to the PWM signal's duty cycle. This analog signal is used to drive the electronic load unit 16.

[0053] Specifically, the PWM-to-DAC unit 15 converts the digital PWM signal output from the MCU controller unit 14 into an analog control signal, enabling the electronic load unit 16 to precisely adjust its operating state according to the amplitude of the analog signal, thus meeting the requirements for precise control of energy release. In other words, through precise PWM-to-analog signal conversion, the power of the electronic load unit 16 can be adjusted more finely, achieving more accurate consumption of the reverse charging current energy of the motor, further improving the performance and reliability of the protection circuit.

[0054] For the electronic load unit 16, it receives the analog control signal output from the PWM to DAC unit 15 and adjusts its own operating state according to the signal. The electronic load unit 16 typically consists of power devices (such as MOSFETs, IGBTs, etc.) and resistors. By controlling the on / off state of the power devices, the current through the resistors is adjusted, thereby achieving energy consumption. For example, the on-resistance of the MOSFET can be adjusted according to the analog control signal to form a discharge circuit. The formula for calculating the discharge power is: P represents the discharge power, Rload represents the load impedance corresponding to the electronic load unit 16, and Vrectified represents the voltage output by the rectifier unit 11. When the amplitude of the analog control signal increases, the energy consumed by the electronic load unit 16 increases; conversely, the energy consumed decreases. Simultaneously, the electronic load unit 16 also receives the first DC voltage output by the rectifier unit 11 and the second voltage output by the first buck unit 12 as its operating power supply.

[0055] In this system, after the battery protection board is turned off, the reverse charging current generated by the motor cannot be released through the battery circuit. The electronic load unit 16 can intervene promptly, providing an effective channel for the reverse charging current. By consuming the excess energy generated by the reverse charging current, it reduces the voltage and current inside the controller, preventing overvoltage breakdown of core controller components (such as MOSFETs) and protecting the controller's safety. Furthermore, based on the intelligent control of the MCU controller unit 14, the electronic load unit 16 can dynamically adjust energy consumption according to different operating conditions. Under special conditions such as long downhill slopes, it increases energy consumption to ensure controller safety; under normal driving conditions, it maintains a low power consumption state to reduce energy waste and improve the electric vehicle's range.

[0056] In summary, this application rectifies the reverse-charge AC power from the motor's three-phase lines into DC power via the rectifier unit 11, and then directly connects it to the electronic load unit 16, forming a discharge channel independent of the battery circuit. Furthermore, the rectified high-voltage DC power is stepped down stage by the first step-down unit 12 (exemplarily a BUCK structure) and the second step-down unit 13 (exemplarily an LDO structure), providing a stable power supply to the MCU controller and electronic load, ensuring continued operation even when the lithium battery protection board is turned off. That is, the reverse-charge current forms a closed loop from the motor's three-phase lines → rectifier unit 11 → electronic load unit 16 → ground, preventing energy accumulation at the MOSFET terminals and utilizing the reverse-charge energy to power its own circuit (without relying on the battery), ensuring the system continues to operate during the protection board's shutdown period, achieving "uninterrupted protection even when power is off."

[0057] Meanwhile, by collecting parameters from both the throttle signal detection unit 17 and the battery voltage detection unit 18, erroneous actions during normal deceleration or short-term downhill driving can be reduced. For example, discharge can be triggered only when the following conditions are met simultaneously: (1) throttle voltage ≤ 0.8V (driver clearly intends to go downhill); (2) rectifier unit 11 output voltage > threshold (reverse charging current intensity meets standard); (3) battery voltage < safety limit (avoid overcharging caused by discharge).

[0058] In addition, the PWM to DAC unit 15 converts the digital PWM signal output by the MCU into an analog voltage signal, linearly controlling the on-resistance of the electronic load. As the MCU monitors the discharge circuit current and voltage in real time and dynamically adjusts the PWM duty cycle, it can improve the matching between the discharge power and the reverse charging energy.

[0059] Furthermore, the throttle signal detection unit 17 is connected in parallel with the original throttle cable, and the battery voltage detection unit 18 is connected in parallel with the original battery terminal, so as not to interfere with the original vehicle signal transmission. Compared with the traditional method of modifying the original vehicle circuit (such as adding a relay or disconnecting the original wiring), maintenance costs can be reduced.

[0060] To facilitate understanding by those skilled in the art, an exemplary program from an MCU controller is provided below:

[0061]

[0062]

[0063]

[0064]

[0065] The specific implementation of each rectifier unit 11 will be described in detail below, by way of example.

[0066] Referring to Figure 2, based on the aforementioned scheme, in some implementations of this application, the rectifier unit 11 includes diodes D3, D4, D5, D6, D7, D8, and capacitor C5. The anodes of diodes D3, D4, and D5 are all connected to the first terminal of capacitor C5; the cathodes of diodes D6, D7, and D8 are all connected to the second terminal of capacitor C5; the anode of diode D8 is connected to the cathode of diode D3; the anode of diode D7 is connected to the cathode of diode D4; the anode of diode D6 is connected to the cathode of diode D5; the anode of diode D8 is connected to the U-phase line of the electric vehicle motor; the anode of diode D7 is connected to the V-phase line of the electric vehicle motor; and the anode of diode D6 is connected to the W-phase line of the electric vehicle motor.

[0067] In the above implementation, a full-bridge rectifier circuit is formed by six diodes and one capacitor, which converts the three-phase AC power generated by the motor into DC power. Capacitor C5 charges and stores energy during rectification, filling the troughs of pulsating voltage and smoothing the output voltage. It should be noted that the UVW phases of the motor refer to the three-phase terminals of the motor, corresponding to the U, V, and W terminals respectively.

[0068] Please refer to Figure 3. Based on the aforementioned scheme, in some implementations of this application, the first step-down unit 12 includes: a DC-DC step-down chip U2, a diode D9, a resistor R25, a resistor R24, a resistor R23, an inductor L3, an inductor L4, a capacitor C6, a capacitor C7, and a capacitor C9. Specifically, the VIN pin of DC-DC step-down chip U2 is connected to the cathode of diode D6 through inductor L3; the VIN pin of DC-DC step-down chip U2 is connected to the GND pin of DC-DC step-down chip U2 through capacitor C6; the GND pin of DC-DC step-down chip U2 is connected to the FB pin of DC-DC step-down chip U2 through resistor R25; the FB pin of DC-DC step-down chip U2 is connected to the VS pin of DC-DC step-down chip U2 through resistor R24 ​​and inductor L4; the IS pin of DC-DC step-down chip U2 is connected to the VS pin of DC-DC step-down chip U2 through resistor R23; the VB pin of DC-DC step-down chip U2 is connected to the VC pin of DC-DC step-down chip U2 through capacitor C7; the cathode of diode D9 is connected to the VS pin of DC-DC step-down chip U2; and the cathode of diode D9 is connected to the VS pin of DC-DC step-down chip U2 through capacitor C9 and inductor L4.

[0069] In the above implementation, the VIN (input voltage pin) of the DC-DC buck chip U2 is connected to the cathode of diode D6 via inductor L3. Inductor L3 smooths the input current and reduces current ripple. Simultaneously, the VIN pin of the DC-DC buck chip U2 is connected to GND (ground pin) via capacitor C6. Capacitor C6 acts as an input filter, removing high-frequency noise from the input voltage and providing a stable DC input voltage for the chip. Next, the GND pin of the DC-DC buck chip U2 is connected to FB (feedback pin) via resistor R25, forming part of the feedback network. The FB pin of the DC-DC buck chip U2 is then connected to VS (output voltage sampling pin) via resistor R24 ​​and inductor L4. Resistors R24 and R25 form a voltage divider network for sampling the output voltage and feeding the sampled signal back to the DC-DC buck chip. This allows the DC-DC buck chip to adjust the output voltage based on the feedback signal, achieving voltage regulation. The IS (current sensing pin) of the DC-DC buck chip U2 is connected to the VS pin through resistor R23. Resistor R23 is used to detect the output current. When the output current exceeds the set value, the chip can limit the current or provide protection through its internal circuitry to prevent damage to the circuit due to overload. The VB (internal circuit power supply pin; some chips may use it for startup or internal circuit bias) of the DC-DC buck chip U2 is connected to VC through capacitor C7. Capacitor C7 helps stabilize the operating voltage of the chip's internal circuitry, improving the stability and reliability of the circuit. The cathode of diode D9 is connected to the VS pin. Diode D9 acts as a freewheeling diode, providing a path when the current in inductor L4 attempts to flow in the reverse direction, preventing high-voltage spikes from damaging the chip or other components. Simultaneously, the VS pin of the DC-DC buck chip U2 is connected to itself through capacitor C9 and inductor L4. Capacitor C9 and inductor L4 together form an output filter network, further smoothing the output voltage and reducing output voltage ripple and noise.

[0070] In summary, this device utilizes the DC-DC buck chip U2 to achieve efficient voltage conversion, significantly reducing energy loss and improving power conversion efficiency compared to linear regulators. Furthermore, through feedback and output filtering networks, this buck unit provides a stable, low-ripple output voltage, meeting the demands of loads with high power quality requirements. The output voltage can be easily set by adjusting the values ​​of the feedback resistors (R24 and R25) to meet the voltage requirements of different loads. Simultaneously, the selection of capacitor and inductor parameters offers flexibility and can be optimized according to specific application scenarios.

[0071] For example, the DC-DC step-down chip U2 can be model EG1198.

[0072] Referring to Figure 3, based on the aforementioned scheme, in some implementations of this application, the second step-down unit 13 includes: a linear regulator chip U5, an inductor L5, a capacitor C8, a capacitor C10, and a capacitor C11. Specifically, the VIN pin of the linear regulator chip U5 is connected to the VS pin of the DC-DC step-down chip U2 via the inductor L4. Capacitors C8, C10, and C9 are connected in parallel in pairs. The VIN pin of the linear regulator chip U5 is connected to the GND pin of the linear regulator chip U5 via capacitor C10 and inductor L5. The VOUT pin of the linear regulator chip U5 is connected to the GND pin of the linear regulator chip U5 via capacitor C11.

[0073] In the above implementation, the VIN pin (input voltage pin) of the linear regulator chip U5 is connected to the VS pin (output voltage sampling pin, here serving as the output terminal) of the preceding DC-DC buck chip U2 via inductor L4. Inductor L4 already provides some filtering in the first buck unit 12; this connection allows the second buck unit 13 to receive the voltage signal from the first buck unit 12. Simultaneously, inductor L4 performs preliminary smoothing of the input signal, reducing high-frequency interference. Capacitors C8, C10, and C9 are connected in parallel near the VIN pin for further filtering of the input voltage, removing high-frequency noise and ripple. Meanwhile, the VIN pin of the linear regulator chip U5 is connected to the GND pin (ground pin) of the linear regulator chip U5 through capacitor C10 and inductor L5. Inductor L5, together with parallel capacitors C8 and C10, forms an input filter network. Inductor L5 further smooths the input current and reduces the impact of current surges on the chip, while the capacitors are responsible for filtering out noise of different frequencies, providing a stable and clean input voltage for the chip. The VOUT pin (output voltage pin) of the linear regulator chip U5 is connected to the GND pin of the linear regulator chip U5 through capacitor C11. Capacitor C11 acts as an output filter capacitor, filtering the output voltage of the linear regulator chip U5, reducing output voltage ripple and noise, making the output voltage more stable, and meeting the power quality requirements of subsequent loads.

[0074] For example, the second step-down unit 13 can be an AMS1117-3.3, which enables precise regulation of the input voltage and extremely low output voltage ripple and noise, effectively preventing interference to the downstream load circuit due to voltage fluctuations.

[0075] Referring to Figure 4, based on the aforementioned scheme, in some implementations of this application, the MCU controller unit 14 includes: a CW32F003E4P7 processor chip U4, a capacitor C12, a resistor R26, a light-emitting diode LED1, and a terminal block H2 (used as a download interface). Specifically, pin VSS of processor chip U4 is connected to pin VDD of processor chip U4 via capacitor C12; pin VDD of processor chip U4 is connected to pin VOUT of linear regulator chip U5; terminal 1 of terminal block H2 is connected to pin VDD of processor chip U4; terminal 2 of terminal block H2 is connected to pin PA02 of processor chip U4; terminal 3 of terminal block H2 is connected to pin PA05 of processor chip U4; pin VDD of processor chip U4 is connected to the anode of light-emitting diode LED1 via resistor R26; and the cathode of light-emitting diode LED1 is connected to pin PB05 of processor chip U4.

[0076] Referring to Figure 5, based on the aforementioned scheme, in some implementations of this application, the PWM to DAC unit 15 includes: capacitor C13, capacitor C14, capacitor C15, resistor R27, and resistor R28. One end of capacitor C13 is connected to pin PB02 of the processor chip U4, and the other end is grounded through resistors R27, R28, and capacitor C15. The common terminal of resistors R27 and R28 is grounded through capacitor C14.

[0077] In the above implementation, one end of capacitor C13 is connected to pin PB02 of processor chip U4. Pin PB02 serves as the output pin of the PWM signal, introducing the PWM signal generated by the MCU into the PWM-to-DAC unit 15. The other end of capacitor C13 serves as the starting point of the signal processing path, connected to the subsequent resistor and capacitor network. Capacitor C13 plays a coupling role here, coupling the PWM signal output by the MCU controller unit 14 to the subsequent conversion circuit, while also suppressing high-frequency interference in the signal and reducing noise introduction during signal transmission. The other end of capacitor C13 is grounded through resistors R27 and R28 and capacitor C15. Resistors R27 and R28 are connected in series, forming a second-order RC low-pass filter network together with capacitor C15. The PWM signal is a digital pulse signal containing rich high-frequency harmonic components. This RC low-pass filter network effectively filters out the high-frequency part of the PWM signal, retaining only its DC component (average value), thereby realizing the conversion of the PWM signal to an analog voltage signal. The values ​​of resistors R27 and R28 affect the filter's cutoff frequency and output impedance, thus impacting the quality and driving capability of the converted analog voltage signal. The common terminal of resistors R27 and R28 is grounded through capacitor C14. Capacitor C14, along with resistors R27 and R28, forms an additional filter branch for further filtering and smoothing of the signal. This can filter out some specific frequency noise that was not completely removed in the main RC filter network, improving the purity of the output analog voltage signal and reducing the impact of ripple and noise on subsequent circuits.

[0078] Compared to dedicated DAC chips, this PWM to DAC unit 15 uses only simple and inexpensive components such as capacitors and resistors, significantly reducing hardware costs. The unit's circuit structure is concise and clear, consisting of only a few capacitors and resistors, with a small number of components and clear connections. This simple circuit structure not only reduces the complexity of hardware design and minimizes interference between components, but also improves the reliability and stability of the circuit. Furthermore, the simple circuit facilitates troubleshooting and repair, reducing product maintenance costs.

[0079] Referring to Figure 6, based on the aforementioned scheme, in some implementations of this application, the electronic load unit 16 includes: comparator U1.1, comparator U3.2, transistor Q2, transistor Q3, transistor Q4, transistor Q5, MOSFET Q1, MOSFET Q6, inductor L1, inductor L2, resistor R1, resistor R9, resistor R7, resistor R8, resistor R5, resistor R6, resistor R4, resistor R3, resistor R2, resistor R22, resistor R21, resistor R20, resistor R18, resistor R19, resistor R16, resistor R17, resistor R14, resistor R15, capacitor C10, capacitor C18, and capacitor C4. In this circuit, the non-inverting input of comparator U1.1 is connected to the common terminal of resistor R28 and capacitor C15. The non-inverting input of comparator U1.1 is connected to its output via a parallel connection of capacitor C18 and resistor R1. The power input of comparator U1.1 is connected to pin VS of DC-DC step-down chip U2 via inductor L4. The power input of comparator U1.1 is grounded via capacitor C10. The inverting input of comparator U1.1 is grounded via resistors R9 and R2. The output of comparator U1.1 is connected to the base of transistor Q2. The base of transistor Q2 is connected to its emitter via resistor R8. The base of transistor Q2 is connected to pin PB03 of processor chip U4 through resistor R7. The collector of transistor Q2 is connected to the base of transistor Q3 through resistor R4. The base of transistor Q3 is connected to the emitter of transistor Q3 through resistor R6. The emitter of transistor Q3 is connected to pin VS of DC-DC step-down chip U2 through inductor L4. The collector of transistor Q3 is connected to the gate of MOSFET Q1 through resistor R4. The gate of MOSFET Q1 is connected to the source of MOSFET Q1 through resistor R3. The drain of MOSFET Q1 is connected to the cathode of diode D6. The drain of MOSFET Q1 is grounded through resistor R2 and inductor L1.The non-inverting input of comparator U3.2 is connected to the common terminal of resistor R28 and capacitor C15. The non-inverting input of comparator U3.2 is connected to its output through a parallel connection of capacitor C15 and resistor R4. The inverting input of comparator U3.2 is grounded through resistors R14 and R22. The output of comparator U3.2 is connected to the base of transistor Q5. The base of transistor Q5 is connected to its emitter through resistor R16. The base of transistor Q5 is connected to pin PB03 of processor chip U4 through resistor R17. The collector of transistor Q5 is connected to the base of transistor Q4 through resistor R19. The base of transistor Q4 is connected to the emitter of transistor Q4 through resistor R18. The emitter of transistor Q4 is connected to pin VS of DC-DC step-down chip U2 through inductor L4. The collector of transistor Q4 is connected to the gate of MOSFET Q6 through resistor R20. The gate of MOSFET Q6 is connected to the source of MOSFET Q6 through resistor R21. The drain of MOSFET Q6 is connected to the cathode of diode D6. The drain of MOSFET Q6 is grounded through resistor R22 and inductor L2.

[0080] In the above implementation, the inverting input of comparator U1.1 is grounded through resistors R9 and R2. Resistors R9 and R2 form a voltage divider circuit, setting a reference threshold voltage for comparator U1.1. When the reference signal voltage at the non-inverting input is higher than the threshold voltage at the inverting input, comparator U1.1 outputs a high level; otherwise, it outputs a low level. The output of comparator U1.1 is connected to the base of transistor Q2, amplifying the comparator's output signal. The base of transistor Q2 is connected to its emitter through resistor R8, stabilizing the transistor's operating point. Simultaneously, the base of transistor Q2 is connected to pin PB03 of processor chip U4 through resistor R7. Processor chip U4 can output a control signal through pin PB03 to intervene in the conduction state of transistor Q2, achieving flexible circuit control. The collector of transistor Q2 is connected to the base of transistor Q3 through resistor R4, further amplifying the signal and transmitting it to transistor Q3 for secondary amplification. The base of transistor Q3 is connected to the emitter of transistor Q3 through resistor R6, stabilizing its operating point. The emitter of transistor Q3 is connected to pin VS of DC-DC step-down chip U2 through inductor L4, obtaining power. The collector of transistor Q3 is connected to the gate of MOSFET Q1 through resistor R4, sending the amplified drive signal to the gate of MOSFET Q1 and controlling the conduction level of MOSFET Q1.

[0081] The gate of MOSFET Q1 is connected to its source via resistor R3. Resistor R3 limits current and stabilizes the gate voltage, preventing damage to the MOSFET from excessive gate voltage. When the drive signal output from transistor Q3 is applied to the gate of MOSFET Q1, it controls the conduction and cutoff of MOSFET Q1, thereby controlling the load current. The drain of MOSFET Q1 is connected to the cathode of diode D6. Diode D6 prevents reverse current flow, protecting circuit components. The drain of MOSFET Q1 is grounded through resistor R2 and inductor L1. Resistor R2 acts as a sampling resistor, converting the load current into a voltage signal for feedback control; inductor L1 smooths the current, reducing current fluctuations.

[0082] Comparator U3.2, transistors Q5 and Q4, MOSFET Q6, and related resistors and inductors constitute another load control channel symmetrical to the circuitry of U1.1. Its operating principle is similar to that of the U1.1 circuitry; by setting different reference thresholds using different voltage divider resistors (resistors R14 and R22), the conduction level of MOSFET Q6 can be independently controlled, thereby regulating the load current of the other channel. The two load channels can operate independently or in conjunction, providing different load current combinations according to actual needs.

[0083] In summary, by comparing the analog voltage signal output from the pre-amplifier PWM to DAC unit 15 with a set reference threshold using a comparator, and then amplifying and driving it through transistors and MOSFETs, the conduction level of the MOSFETs can be precisely controlled, thereby achieving precise regulation of the load current. This precise control capability allows the electronic load unit 16 to simulate various load characteristics, meeting the load current accuracy requirements of different testing and application scenarios.

[0084] Referring to Figure 7, based on the aforementioned scheme, in some implementations of this application, the throttle signal detection unit 17 includes: a terminal block J4, a diode D10, a capacitor C17, a capacitor C16, a resistor R29, a resistor R30, and a resistor R31. The terminal block J4 is connected to the throttle signal line of the electric vehicle. Terminal 2 of the terminal block J4 is connected to terminal 3 of the terminal block J4 via resistor R30. Terminal 2 of the terminal block J4 is connected to terminal 3 of the terminal block J4 via resistor R29 and capacitor C17. The common terminal of resistor R29 and capacitor C17 is connected to pin PA06 of the processor chip U4. Terminal 1 of the terminal block J4 is grounded via capacitor C16. Terminal 1 of the terminal block J4 is connected to pin VOUT of the linear regulator chip U5 via resistor R31. The anode of diode D10 is connected to pin VOUT of the linear regulator chip U5, and the cathode of diode D10 is connected to terminal 1 of the terminal block J4.

[0085] Terminal block J4 serves as the interface between the throttle signal and the detection unit, with its terminals connected to the throttle signal line of the electric vehicle. It's important to note that the throttle signal line outputs an analog voltage signal that varies with the throttle rotation angle, reflecting the rider's intention to control the electric vehicle's speed. Terminal 1 of terminal block J4 is connected to pin VOUT of linear regulator chip U5 via resistor R31. Linear regulator chip U5 provides a stable operating voltage to the throttle signal line, ensuring the throttle can output a signal correctly. Simultaneously, the anode of diode D10 is connected to pin VOUT of linear regulator chip U5, and the cathode is connected to terminal 1 of terminal block J4. Diode D10 provides reverse protection, preventing damage to linear regulator chip U5 from abnormal external voltage (such as accidental reverse connection of the throttle signal line). Terminal 1 of terminal block J4 is grounded via capacitor C16. Capacitor C16 filters the power supply output from linear regulator chip U5, removing high-frequency noise and ripple, providing a clean and stable power environment for the throttle signal line, and improving the accuracy of the throttle signal. Terminals 2 and 3 of terminal block J4 are the output terminals for the throttle signal. Terminal 2 is connected to terminal 3 via resistor R30, and also connected to terminal 3 via resistor R29 and capacitor C17. These two paths form a network for acquiring the throttle signal. Resistor R30 provides current limiting and voltage division, while resistor R29 and capacitor C17 form an RC filter circuit. The common terminal of resistor R29 and capacitor C17 is connected to pin PA06 of processor chip U4, sending the filtered throttle signal to the processor chip. The RC filter circuit effectively filters out high-frequency interference and noise in the throttle signal, making the signal received by the processor chip smoother and more stable, thereby improving the accuracy and reliability of throttle signal detection.

[0086] In summary, filtering the throttle signal using the RC filter circuit effectively removes high-frequency noise and interference, resulting in a cleaner and more stable signal received by the processor chip. The reverse protection function of diode D10 effectively prevents damage to the linear regulator chip U5 from accidental reverse connection of the throttle signal line or other abnormal voltage conditions, protecting the power supply section of the entire detection unit, improving circuit reliability and stability, and reducing the risk of circuit failure.

[0087] Referring to Figure 8, based on the aforementioned scheme, in some implementations of this application, the battery voltage detection unit 18 includes: capacitor C2, resistor R32, resistor R33, resistor R34, and resistor R35. One end of resistor R35 is grounded and connected to the negative terminal of the electric vehicle's power supply battery, while the other end is connected to the positive terminal of the electric vehicle's power supply battery via resistors R34, R33, and R32 in sequence. Capacitor C2 and resistor R35 are connected in parallel, and the common terminal of resistors R35 and R34 is connected to pin PA04 of the processor chip U4.

[0088] In the above implementation, one end of resistor R35 is grounded and connected to the negative terminal of the electric vehicle's battery, while the other end is connected to the positive terminal of the battery via resistors R34, R33, and R32. These four resistors form a series voltage divider network, which proportionally reduces the battery's high voltage to a range that the processor chip can safely receive and process. Capacitor C2 is connected in parallel with resistor R35. Capacitor C2 acts as a filter, absorbing high-frequency noise and ripple in the circuit. Since the battery's output voltage may fluctuate or be affected by external electromagnetic interference, this noise can be superimposed on the voltage signal after voltage division, affecting the processor chip U4's accurate detection of the battery voltage. Capacitor C2 bypasses this noise, making the voltage signal transmitted to pin PA04 of processor chip U4 more stable and accurate, reducing measurement errors. The common terminal of resistors R35 and R34 is connected to pin PA04 of processor chip U4; the voltage signal at this common terminal is the battery voltage sampling signal after voltage division and filtering. The processor chip reads the voltage signal through pin PA04 and uses its internal analog-to-digital converter (ADC) to convert the analog voltage signal into a digital signal for subsequent calculations and processing, such as calculating the remaining battery power and determining whether the battery is overcharged or over-discharged.

[0089] This application also provides a protection device for an electric vehicle controller, which is the protection circuit for an electric vehicle controller described above. It can be made into a protection device for the electric vehicle controller by encapsulating the circuit board containing the protection circuit within a housing, thus facilitating user operation and providing convenience.

[0090] It will be apparent to those skilled in the art that this application is not limited to the details of the exemplary embodiments described above, and that this application can be implemented in other specific forms without departing from the spirit or essential characteristics of this application. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this application is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this application. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A protection circuit for an electric vehicle controller, characterized in that, The device includes a rectifier unit, a first buck unit, a second buck unit, an MCU controller unit, a PWM to DAC unit, and an electronic load unit connected in series. It also includes a throttle signal detection unit and a battery voltage detection unit connected to the MCU controller unit. The output of the rectifier unit is connected to the electronic load unit, and the output of the first buck unit is also connected to the electronic load unit. The input of the rectifier unit is connected to the three-phase lines of the electric vehicle motor, the input of the throttle signal detection unit is connected to the throttle signal line of the electric vehicle, and the battery voltage detection unit is connected to the output of the electric vehicle's power supply battery.

2. The circuit according to claim 1, characterized in that, The rectifier unit includes diodes D3, D4, D5, D6, D7, D8, and capacitor C5. The anodes of diodes D3, D4, and D5 are connected to the first terminal of capacitor C5. The cathodes of diodes D6, D7, and D8 are connected to the second terminal of capacitor C5. The anode of diode D8 is connected to the cathode of diode D3. The anode of diode D7 is connected to the cathode of diode D4. The anode of diode D6 is connected to the cathode of diode D5. The anode of diode D8 is connected to the U-phase line of the electric vehicle motor. The anode of diode D7 is connected to the V-phase line of the electric vehicle motor. The anode of diode D6 is connected to the W-phase line of the electric vehicle motor.

3. The circuit according to claim 2, characterized in that, The first step-down unit includes: a DC-DC step-down chip U2, a diode D9, resistors R25, R24, and R23, inductors L3 and L4, and capacitors C6, C7, and C9. The VIN pin of the DC-DC step-down chip U2 is connected to the cathode of the diode D6 via the inductor L3; the VIN pin of the DC-DC step-down chip U2 is connected to the GND pin of the DC-DC step-down chip U2 via the capacitor C6; and the GND pin of the DC-DC step-down chip U2 is connected to the FB pin of the DC-DC step-down chip U2 via the resistor R25. Pin FB of chip U2 is connected to pin VS of DC-DC step-down chip U2 through resistor R24 ​​and inductor L4. Pin IS of DC-DC step-down chip U2 is connected to pin VS of DC-DC step-down chip U2 through resistor R23. Pin VB of DC-DC step-down chip U2 is connected to pin VC of DC-DC step-down chip U2 through capacitor C7. The cathode of diode D9 is connected to pin VS of DC-DC step-down chip U2. The cathode of diode D9 is connected to pin VS of DC-DC step-down chip U2 through capacitor C9 and inductor L4.

4. The circuit according to claim 3, characterized in that, The second step-down unit includes: a linear regulator chip U5, an inductor L5, a capacitor C8, a capacitor C10, and a capacitor C11; wherein, the VIN pin of the linear regulator chip U5 is connected to the VS pin of the DC-DC step-down chip U2 through the inductor L4; the capacitors C8, C10, and C9 are connected in parallel in pairs; the VIN pin of the linear regulator chip U5 is connected to the GND pin of the linear regulator chip U5 through the capacitor C10 and the inductor L5; and the VOUT pin of the linear regulator chip U5 is connected to the GND pin of the linear regulator chip U5 through the capacitor C11.

5. The circuit according to claim 4, characterized in that, The MCU controller unit includes: a CW32F003E4P7 processor chip U4, a capacitor C12, a resistor R26, a light-emitting diode LED1, and a terminal block H2. The VSS pin of the processor chip U4 is connected to the VDD pin of the processor chip U4 via the capacitor C12. The VDD pin of the processor chip U4 is connected to the VOUT pin of the linear regulator chip U5. Terminal 1 of the terminal block H2 is connected to the VDD pin of the processor chip U4. Terminal 2 of the terminal block H2 is connected to the PA02 pin of the processor chip U4. Terminal 3 of the terminal block H2 is connected to the PA05 pin of the processor chip U4. The VDD pin of the processor chip U4 is connected to the anode of the light-emitting diode LED1 via the resistor R26. The cathode of the light-emitting diode LED1 is connected to the PB05 pin of the processor chip U4.

6. The circuit according to claim 5, characterized in that, The PWM to DAC unit includes: capacitor C13, capacitor C14, capacitor C15, resistor R27, and resistor R28; wherein, one end of capacitor C13 is connected to pin PB02 of processor chip U4, and the other end is grounded through resistor R27, resistor R28, and capacitor C15, and the common terminal of resistor R27 and resistor R28 is grounded through capacitor C14.

7. The circuit according to claim 6, characterized in that, The electronic load unit includes: comparator U1.1, comparator U3.2, transistors Q2, Q3, Q4, and Q5, MOSFETs Q1 and Q6, inductors L1 and L2, resistors R1, R9, R7, R8, R5, R6, R4, R3, R2, R22, R21, R20, R18, R19, R16, R17, R14, and R15, and capacitors C10, C18, and C4; wherein, the non-inverting input terminal of comparator U1.1 is connected to the... The common terminal of resistor R28 and capacitor C15 is connected. The non-inverting input of comparator U1.1 is connected to its output through capacitor C18 and resistor R1 connected in parallel. The power input of comparator U1.1 is connected to pin VS of DC-DC step-down chip U2 through inductor L4. The power input of comparator U1.1 is grounded through capacitor C10. The inverting input of comparator U1.1 is grounded through resistors R9 and R2. The output of comparator U1.1 is connected to the base of transistor Q2. The base of transistor Q2 is connected to the emitter of transistor Q2 through resistor R8. The base of transistor Q2 is connected to pin PB03 of processor chip U4 through resistor R7. The collector of transistor Q2 is connected to the base of transistor Q3 through resistor R4. The base of transistor Q3 is connected to the emitter of transistor Q3 through resistor R6. The emitter of transistor Q3 is connected to pin VS of DC-DC step-down chip U2 through inductor L4. The collector of transistor Q3 is connected to the gate of MOSFET Q1 through resistor R4. The gate of MOSFET Q1... The source of the MOSFET Q1 is connected to the resistor R3, and the drain of the MOSFET Q1 is connected to the cathode of the diode D6. The drain of the MOSFET Q1 is grounded through the resistor R2 and the inductor L1. The non-inverting input of the comparator U3.2 is connected to the common terminal of the resistor R28 and the capacitor C15. The non-inverting input of the comparator U3.2 is connected to the output of the comparator U3.2 through the parallel capacitor C15 and the resistor R4. The inverting input of the comparator U3.2 is grounded through the resistor R14 and the resistor R22.The output terminal of transistor 2 is connected to the base of transistor Q5. The base of transistor Q5 is connected to the emitter of transistor Q5 through resistor R16. The base of transistor Q5 is connected to pin PB03 of processor chip U4 through resistor R17. The collector of transistor Q5 is connected to the base of transistor Q4 through resistor R19. The base of transistor Q4 is connected to the emitter of transistor Q4 through resistor R18. The emitter of transistor Q4 is connected to pin VS of DC-DC step-down chip U2 through inductor L4. The collector of transistor Q4 is connected to the gate of MOSFET Q6 through resistor R20. The gate of MOSFET Q6 is connected to the source of MOSFET Q6 through resistor R21. The drain of MOSFET Q6 is connected to the cathode of diode D6. The drain of MOSFET Q6 is grounded through resistor R22 and inductor L2.

8. The circuit according to claim 5, characterized in that, The throttle signal detection unit includes: a terminal block J4, a diode D10, a capacitor C17, a capacitor C16, a resistor R29, a resistor R30, and a resistor R31. The terminal block J4 is connected to the throttle signal line of the electric vehicle. Terminal 2 of the terminal block J4 is connected to terminal 3 of the terminal block J4 via the resistor R30. Terminal 2 of the terminal block J4 is connected to terminal 3 of the terminal block J4 via the resistor R29 and the capacitor C17. The common terminal of the resistor R29 and the capacitor C17 is connected to pin PA06 of the processor chip U4. Terminal 1 of the terminal block J4 is grounded via the capacitor C16. Terminal 1 of the terminal block J4 is connected to pin VOUT of the linear regulator chip U5 via the resistor R31. The anode of the diode D10 is connected to pin VOUT of the linear regulator chip U5, and the cathode of the diode D10 is connected to terminal 1 of the terminal block J4.

9. The circuit according to claim 5, characterized in that, The battery voltage detection unit includes: capacitor C2, resistor R32, resistor R33, resistor R34, and resistor R35; wherein, one end of resistor R35 is grounded and used to connect to the negative terminal of the electric vehicle's power supply battery, and the other end is connected to the positive terminal of the electric vehicle's power supply battery through resistors R34, R33, and R32 in sequence; capacitor C2 and resistor R35 are connected in parallel; and the common terminal of resistors R35 and R34 is connected to pin PA04 of processor chip U4.

10. A protection device for an electric vehicle controller, characterized in that, Includes a protection circuit for an electric vehicle controller as described in any one of claims 1-9.

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