Circuit for active short circuit protection
By introducing a hardware safety protection unit into the motor controller, the bridge arm units are ensured to close in a predetermined sequence, thus solving the motor safety and reliability problems caused by software control failures and achieving higher safety and cost-effectiveness.
Patent Information
- Application Number
- CN202520560137.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-27
- Publication Date
- 2026-02-27
- Estimated Expiration
- 2035-03-27
AI Technical Summary
Existing active short-circuit protection strategies for motor controllers rely on software control, which carries the risk of protection failure due to software malfunction or control chip failure, thus reducing the reliability and safety of the motor.
A hardware safety protection unit is used as a backup for the control unit to ensure that the first bridge arm unit and the second bridge arm unit close in a predetermined order. Active short-circuit protection is achieved through hardware intervention, including a reverse module and a delay module to ensure the safe switching of power devices.
It improves the safety and reliability of the motor, reduces hardware costs, and provides additional protection mechanisms in case of software failure.
Smart Images
Figure CN223957470U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to motor control technical field, concretely relates to a circuit for initiative short circuit protection. BACKGROUND
[0002] With the development of new energy electric car, the demand of public for car is also more and more diversified. As the core of new energy electric car, the safety performance of motor is also concerned by users. If the motor controller output abnormal torque, cause the vehicle to appear the unexpected acceleration and deceleration state, will cause the vehicle to be in the out of control state, and then endanger the safety of the driver and passenger. The existing motor controller usually detects low voltage power failure, control chip failure and DC high voltage overvoltage any one fault, and the motor controller usually adopts initiative short circuit protection strategy, that is, the motor controller controls three power devices of upper bridge arm to be in the off state, and three power devices of lower bridge arm are all in the on state, so that the motor coil and the three power devices of lower bridge arm form a loop, at this time, the motor will generate reverse brake torque, so that the vehicle stops slowly, and the personal safety of the driver and passenger is guaranteed.
[0003] The initiative short circuit protection strategy in the prior art usually detects the fault by software, and selects the upper and lower bridge off or on through software control. If the software appears to run away or the control chip fails, the initiative short circuit protection will also be invalid, which will lead to the occurrence of vehicle accident, thereby reducing the reliability of the motor. UTILITY MODEL CONTENTS
[0004] The utility model provides a circuit for initiative short circuit protection, at least has initiative short circuit safety reliable, circuit cost low and the like advantages in view of the technical problem of safety not high or hardware intervention control too complex of software control of the circuit of initiative short circuit protection in the prior art.
[0005] The utility model provides a circuit for initiative short circuit protection, it includes: control unit, hardware safety protection unit, first bridge arm unit and second bridge arm unit,
[0006] First bridge arm unit and second bridge arm unit are connected to control unit respectively,
[0007] Hardware safety protection unit is connected to control unit, and first control port of hardware safety protection unit and second control port of second bridge arm unit are connected respectively,
[0008] Hardware safety protection unit includes reverse module and delay module.
[0009] Specifically, one of the main technical ideas of the utility model is that the hardware safety protection unit is used as the backup of the control unit active short circuit process, the first bridge arm unit and the second bridge arm unit are ensured to be closed in a predetermined order, and the safety and reliability of the motor are improved.
[0010] Further, the circuit comprises a fault detection unit;
[0011] The fault detection unit is connected to the control unit, or the hardware safety protection unit.
[0012] Further, the control unit is connected to the first control port of the first bridge arm unit through an EN data line, and is connected to the first HI port and the first LI port of the first bridge arm unit through an H-PWM data line and an L-PWM data line respectively.
[0013] The control unit is connected to the second HI port and the second LI port of the second bridge arm unit through the H-PWM data line and the L-PWM data line respectively.
[0014] Specifically, another possible technical idea of the utility model is that the control unit controls the first bridge arm unit and the second bridge arm unit through an EN data line, an H-PWM data line and an L-PWM data line, and the cost of the circuit structure is reduced.
[0015] Further, the hardware safety protection unit is connected to the first control port.
[0016] The hardware safety protection unit is connected to the second control port through the reverse module and the delay module arranged in sequence.
[0017] Specifically, another main technical idea of the utility model is that the function structure of the hardware safety protection unit is planned and designed, the function of the hardware safety protection unit is ensured, and the structural cost of the hardware safety protection unit is effectively reduced.
[0018] Further, the reverse module comprises a reverser, and the delay module comprises a resistor and a capacitor.
[0019] The resistor is arranged between the reverser and the second control port.
[0020] One end of the capacitor is grounded, and the other end is connected to the resistor.
[0021] Optionally, the first bridge arm unit comprises a first bridge arm drive chip and a first bridge arm power device.
[0022] The first bridge arm driving chip is used for obtaining control signals of the first control port, the first HI port and the first LI port, and controlling opening and closing of the first bridge arm power device according to corresponding control signals.
[0023] The second bridge arm unit comprises a second bridge arm driving chip and a second bridge arm power device.
[0024] The second bridge arm driving chip is used for obtaining control signals of the second control port, the second HI port and the second LI port, and controlling opening and closing of the second bridge arm power device according to corresponding control signals.
[0025] Further, the first bridge arm driving chip is connected to the first bridge arm power device through a first HO data line and a first LO data line.
[0026] The second bridge arm driving chip is connected to the second bridge arm power device through a second HO data line and a second LO data line.
[0027] Optionally, the fault detection unit comprises bus voltage detection, low-voltage power supply detection and control unit detection.
[0028] In conclusion, the utility model provides a kind of circuit for active short-circuit protection, its main technical idea at least has the following advantages: the utility model uses hardware safety protection unit as the backup of control unit active short-circuit process, ensure that first bridge arm unit and second bridge arm unit are closed according to predetermined order, to further improve the safety and reliability of motor. BRIEF DESCRIPTION OF DRAWINGS
[0029] The utility model will be further described in detail below in connection with the drawings and preferred embodiments, but those skilled in the art will appreciate that these drawings are only drawn for the purpose of explaining preferred embodiments, thus should not be regarded as the limitation to the scope of the utility model. In addition, unless specifically pointed out, the drawings only schematically show the composition or structure conceptually represented described object and can include exaggerated display, and the drawings are not necessarily drawn to scale.
[0030] Fig. 1 The utility model provides the structural diagram of the circuit of active short-circuit protection in prior art;
[0031] Fig. 2 The utility model provides the structural diagram of the circuit of active short-circuit protection in prior art;
[0032] Fig. 3 The utility model provides the structural diagram of the circuit of active short-circuit protection in prior art. DETAILED DESCRIPTION
[0033] The utility model discloses a kind of active short-circuit protection circuits, as shown in the accompanying drawings! Figs. 1 to 3 The utility model will be described in detail.
[0034] In order to make the purpose, technical scheme and advantages of the utility model more clear and obvious, the utility model will be further described in detail below with reference to the drawings and examples. It should be understood that the specific examples described herein are only used to explain the utility model, and are not used to limit the utility model.
[0035] The main technical idea of the utility model is to use the hardware safety protection unit as the backup of the control unit active short-circuit protection, to improve the reliability of circuit control.
[0036] In order to explain the prior art, please refer to Fig. 1 The structure diagram of the circuit for active short-circuit protection provided by the utility model is shown in the accompanying drawings.
[0037] In the prior art, the active short-circuit function of the motor is controlled by software, so that Fig. 1 The above three power devices (corresponding to the three power devices in the first bridge arm unit of the utility model) and the below three power devices (corresponding to the three power devices in the second bridge arm unit of the utility model) are described. In the software control process, the above three power devices need to be turned off first, and then the below three power devices are turned off, so as to realize the active short-circuit protection function of the software. When the software control fails, it is impossible to ensure that the power devices are turned off in the above order, so that the above three power devices and the below three power devices are in a straight-through state, which in turn causes instantaneous damage to the power devices.
[0038] Further, the power device includes IGBT.
[0039] Further, please refer to Fig. 2 The structure diagram of the circuit for active short-circuit protection provided by an embodiment of the utility model is shown in the accompanying drawings.
[0040] Example 1
[0041] The utility model provides a kind of circuit for active short circuit protection comprising: control unit, hardware safety protection unit, first bridge arm unit and second bridge arm unit;The first bridge arm unit and the second bridge arm unit are connected to the control unit respectively;The hardware safety protection unit is connected to the control unit, and the hardware safety protection unit is connected with the first control port of the first bridge arm unit and the second control port of the second bridge arm unit respectively;Reverse module and delay module are provided between the hardware safety protection unit and the second bridge arm unit.The working principle of the utility model is as follows: under normal circumstances, control unit controls first bridge arm unit and second bridge arm unit to be turned on and off according to order, to realize the active short circuit protection function of motor;When control unit fails, because hardware safety protection unit is interconnected with control unit, the failure state of control unit can be acquired in real time, hardware safety protection unit intervenes control, and first bridge arm unit and second bridge arm unit are controlled to be turned on and off according to order by first control port and second control port, to realize active short circuit protection function further.
[0042] Further, please see Fig. 3 The utility model provides a kind of circuit for active short circuit protection of structure schematic view of another embodiment of the utility model.
[0043] Example 2
[0044] On the basis of embodiment 1, the utility model provides embodiment 2. Embodiment 2 relates to specific circuit structure. Among them, control unit includes MCU and so on micro control unit, micro control unit (Micro controller Unit;MCU), is the frequency and specification of central processing unit make proper reduction, and the memory (memory), counter (Timer), USB, AD conversion, UART, PLC, DMA and so on peripheral interface, even LCD drive circuit are integrated on single chip, form the computer of chip level, for different application situation do different combination control, such as mobile phone, PC peripheral, remote controller, automobile electronics, motor and so on, hardware safety protection unit includes SBC, SBC (System Basic Chip, system basic chip), it is a kind of independent chip including power supply, communication, monitoring and diagnosis, safety detection and so on Characteristics, first bridge arm unit and second bridge arm unit include drive chip and power device, for the distinction of the port, data line and so on contained to first, second are named. Therefore, in embodiment 2, MCU and SBC are interconnected, MCU is connected with the first control port of first bridge arm drive chip (EN port in the illustration) by EN data line, simultaneously MCU is connected respectively in the first HI port and the first LI port of first bridge arm drive chip and the second HI port and the second LI port of second bridge arm drive chip by H-PWM data line and L-PWM data line, to realize the initiative short-circuit protection function of MCU, and SBC is connected in the first control port (EN port) of first bridge arm drive chip and the second control port (ASC port) of second bridge arm drive chip, reverse ware, resistance and capacitor are arranged between SBC and second control port, wherein, resistance is arranged between reverse ware and second control port, one end of capacitor is grounded, and its other end is connected after resistance, to realize the initiative short-circuit protection function of hardware. Meanwhile, first bridge arm drive chip and first bridge arm power device are connected by first HO data line and first LO data line, and second bridge arm drive chip and second bridge arm power device are connected by second HO data line and second LO data line.Therefore, the working principle of the embodiment 2 is that: when the MCU works normally, the MCU sends an enable signal to the first control port through the EN data line, and sends control signals to the first bridge arm drive chip and the second bridge arm drive chip through the H-PWM data line and the L-PWM data line respectively, and the first bridge arm drive chip and the second bridge arm drive chip send control signals to the first bridge arm power device and the second bridge arm power device through the first HO data line and the first LO data line and the second HO data line and the second LO data line respectively according to the control signals, so that the first bridge arm power device and the second bridge arm power device are closed in sequence, thereby realizing the active short-circuit protection function of the motor; when the MCU is abnormal, the SBC intervenes, and the SBC sends a control signal to the first bridge arm drive chip through the EN data line and sends a control signal to the second bridge arm drive chip through the ASC data line, so that the first bridge arm power device and the second bridge arm power device are closed in sequence, thereby realizing the additional active short-circuit protection function of the hardware. The inverter is used for inverting the signal sent by the SBC, and the resistance and the capacitor are used for delay control, so as to realize the turn-off of the first bridge arm power device first, and then the turn-on of the second bridge arm power device.
[0045] It is worth explaining that the first bridge arm power device and the second bridge arm power device correspond to Fig. 1 the three upper power devices and the three lower power devices.
[0046] Optionally, the resistance includes an adjustable resistance, so as to realize the adjustment of different delay times.
[0047] On the basis of the embodiment 1 or the embodiment 2, the circuit comprises a fault detection unit; the fault detection unit is connected to the control unit, or the hardware safety protection unit.
[0048] Optionally, the fault detection unit comprises bus voltage detection, low-voltage power supply detection and control unit detection.
[0049] The utility model is introduced in detail above, and the principle and implementation mode of the utility model are described by applying specific examples in the utility model. The description of the first embodiment is only used to help understand the utility model and the core idea. It should be pointed out that, for ordinary skilled persons in the technical field, the utility model can be improved and modified in several ways without departing from the principle of the utility model, and these improvements and modifications also fall within the protection scope of the utility model claims.
Claims
1. A circuit for active short-circuit protection, characterized in that, include: Control unit, hardware security protection unit, first bridge arm unit and second bridge arm unit; The first bridge arm unit and the second bridge arm unit are respectively connected to the control unit; The hardware security protection unit is connected to the control unit, and the hardware security protection unit is connected to the first control port of the first bridge arm unit and the second control port of the second bridge arm unit respectively. A reverse module and a delay module are provided between the hardware security protection unit and the second bridge arm unit.
2. The circuit for active short-circuit protection as described in claim 1, characterized in that, The circuit includes a fault detection unit; The fault detection unit is connected to the control unit or the hardware security protection unit.
3. A circuit for active short-circuit protection as described in claim 1 or 2, characterized in that, The control unit is connected to the first control port of the first bridge arm unit via the EN data line, and is connected to the first HI port and the first LI port of the first bridge arm unit via the H-PWM data line and the L-PWM data line, respectively. The control unit is connected to the second HI port and the second LI port of the second bridge arm unit via the H-PWM data line and the L-PWM data line, respectively.
4. The circuit for active short-circuit protection as described in claim 3, characterized in that, The hardware security protection unit is connected to the first control port; The hardware security protection unit is connected to the second control port via the reverse module and the delay module arranged in sequence.
5. The circuit for active short-circuit protection as described in claim 4, characterized in that, The inverting module includes an inverter, and the delay module includes a resistor and a capacitor; The resistor is positioned between the inverter and the second control port; One end of the capacitor is grounded, and the other end is connected to the resistor.
6. The circuit for active short-circuit protection as described in claim 3, characterized in that, The first bridge arm unit includes a first bridge arm driver chip and a first bridge arm power device; The first bridge arm driver chip is used to acquire the control signals of the first control port, the first HI port and the first LI port, and control the opening and closing of the first bridge arm power device according to the corresponding control signals; The second bridge arm unit includes a second bridge arm driver chip and a second bridge arm power device; The second bridge arm driver chip is used to acquire the control signals of the second control port, the second HI port, and the second LI port, and to control the opening and closing of the second bridge arm power device according to the corresponding control signals.
7. The circuit for active short-circuit protection as described in claim 6, characterized in that, The first bridge arm driver chip is connected to the first bridge arm power device through the first HO data line and the first LO data line. The second bridge arm driver chip is connected to the second bridge arm power device via the second HO data line and the second LO data line.
8. A circuit for active short-circuit protection as described in claim 2, characterized in that, The fault detection unit includes bus voltage detection, low-voltage power supply detection, and control unit detection.