A five-phase permanent magnet synchronous motor overcurrent control method combining software and hardware

Abstract

The present invention discloses a five-phase permanent magnet synchronous motor overcurrent control method that combines software and hardware, and belongs to the technical field of power generation, power transformation or power distribution. The current information collected by each phase current sensor is converted into a dual-pulse DC signal through a precision rectifier circuit, and then the dual-pulse DC signal and the reference signal are compared to generate an independent overcurrent pulse signal. The five-phase independent overcurrent pulse signals are connected at the output end of the comparator in a "line-AND" manner to achieve pulse signal fusion and immediately block the IGBT drive signal. The corresponding I / O port of the microcontroller is configured as an interrupt input to quickly respond to the overcurrent pulse line-AND signal, and then the IGBT drive signal is blocked in a pulse-by-pulse manner and reopened after one switching cycle. After the number of overcurrent pulses reaches a preset value, the driver is completely turned off and marked as a continuous overcurrent event. The present invention is simple and reliable and can effectively avoid false protection actions.

Description

Technical Field

[0001] The present invention discloses a five-phase permanent magnet synchronous motor overcurrent control method that combines software and hardware. The method adopts a precision rectifier circuit and a comparison circuit and realizes motor overcurrent detection and overcurrent pulse fusion through a "line-and" method. The IGBT drive signal is initially and quickly blocked, and the overcurrent pulse is also fed back to the controller in an interrupt manner. The controller controls the current peak value in a pulse-by-pulse manner based on this signal. In this way, the drive system can undisturbedly pass through short-term overcurrent (or false overcurrent) events. The method belongs to the technical field of power generation, transformation or distribution. Background Art

[0002] The electrification of transportation has been a major technological revolution globally in recent years, rapidly expanding from electric vehicles to electric aircraft, electric ships, electric trains, and other fields. Multiphase electric drive technology is highly anticipated in the next generation of electrified transportation systems. Five-phase permanent magnet synchronous motors, with their high power density, excellent fault tolerance, and low vibration and noise, hold broad application prospects in these areas.

[0003] Five-phase permanent magnet synchronous motors typically operate in harsh environments, making rotor stalls and overloads prone to short circuits or overcurrents, which can jeopardize the safe operation of the drive system. To meet electrical safety requirements, single-cycle motor current control or limitation is often required. Common single-cycle motor current control technologies for short-circuit and overcurrent events in motor drive systems include closed-loop feedback control and pulse-by-pulse current limiting. The closed-loop current regulators used in closed-loop feedback control cannot meet the high response speed of cycle-by-cycle modulation. Existing pulse-by-pulse current limiting control technologies are primarily software-based and hardware-implemented. Software-based pulse-by-pulse current limiting first detects overcurrent and then applies pulse-by-pulse control. However, the accuracy of overcurrent detection is susceptible to sampling noise, and the response speed is limited by the processing speed of the digital controller and the conversion rate of the integrated ADC. Pulse-by-pulse current limiting control technology implemented through hardware such as FPGA or CPLD increases cost while improving response speed. The narrow hysteresis loop width causes the IGBT to operate at a very high switching frequency, causing the IGBT device to quickly accumulate heat in a short period of time. The ADC conversion rate and sampling noise level are also important factors that restrict reliability.

[0004] In summary, the present invention aims to propose a five-phase permanent magnet synchronous motor overcurrent control method that combines software and hardware to overcome the defects of the pulse-by-pulse current limiting control technology for short circuit or overcurrent events in the motor drive system. Summary of the Invention

[0005] The purpose of the present invention is to address the deficiencies of the above-mentioned background technology and provide a five-phase permanent magnet synchronous motor overcurrent control method that combines software and hardware. The method uses a hardware circuit to identify motor overcurrent events and quickly shut down the drive pulse, and uses a software algorithm to control the current peak on the switching cycle scale, so as to more accurately, reliably and quickly achieve the purpose of the invention of motor overcurrent protection, and solve the technical problem that the existing pulse-by-pulse current limiting control technology for overcurrent events in motor drive systems cannot take into account both reducing hardware costs and improving response speed.

[0006] To achieve the aforementioned objectives, the present invention employs the following technical solution: a hardware circuit identifies motor overcurrent events and rapidly shuts off drive pulses. The hardware circuit includes an overcurrent detection circuit that detects overcurrent in each phase of the five-phase motor input AC current, and an overcurrent protection circuit controlled by an overcurrent pulse line and signal and an enable / block signal. A software control algorithm determines whether the motor is experiencing a continuous overcurrent, a short-term overcurrent anomaly, or a false overcurrent, thereby controlling the current peak value on a switching cycle scale.

[0007] The overcurrent detection circuit for each phase of the five-phase permanent magnet synchronous motor input AC current is the same, and the overcurrent detection circuit for each phase of the input AC current includes: a precision rectifier circuit, an EMI filter circuit, a comparison circuit, and a "line-and" output circuit.

[0008] The precision rectifier circuit converts the single-phase input AC signal collected by the current sensor into a double-pulse DC signal.

[0009] The EMI filter circuit is composed of resistors and capacitors connected in series and parallel, and is used to filter out high-frequency interference signals in the double-pulse DC signal output by the precision rectifier circuit.

[0010] The comparison circuit is implemented using an operational amplifier. The filtered dual-pulse DC signal is connected to the inverting input of the operational amplifier, and the reference level is connected to the non-inverting input of the operational amplifier. Overcurrent is determined by comparing the filtered dual-pulse DC signal with the reference level. The reference level is selected to be 1.5 to 5 times the rated peak value of the input AC current signal. A proportional operational amplifier circuit processes the Hall effect current sensor power supply to generate a stable reference level. The operational amplifier has an open-drain output and is connected to a pull-up resistor to a high level. When the input AC current is overcurrent, the operational amplifier outputs a low level, and vice versa.

[0011] The wired-AND output circuit is used to combine independent overcurrent pulse signals to produce a wired-AND overcurrent pulse signal. The outputs of the five comparator circuits are connected to a single output using wired-AND logic, forming a wired-AND output circuit. When the five-phase permanent magnet synchronous motor is operating normally, the output of the wired-AND output circuit is high. However, if any of the five-phase permanent magnet synchronous motor's input AC currents experiences an overcurrent, the output of the wired-AND output circuit is pulled low. The combined pulse signal from the wired-AND output circuit can be used to quickly block the IGBT drive signal, preventing a continued increase in current. The overcurrent pulse wired-AND signal is then transmitted to the overcurrent protection circuit. When the wired-AND signal is pulled low, the overcurrent protection circuit blocks the drive signals for all IGBTs in the inverter. This achieves instant blocking of all IGBT drive signals from a hardware perspective, preventing further current increases and achieving rapid current limiting to meet the required overcurrent control response speed.

[0012] In order to prevent the hysteresis effect caused by the overcurrent pulse line and signal turning on or blocking the IGBT drive signal, and to avoid the possibility of the hardware circuit erroneously blocking the IGBT drive signal due to a false overcurrent event of the motor, a software control algorithm is implemented through a microcontroller to determine whether the motor is continuously overcurrent, short-term overcurrent abnormal or false overcurrent. The working mode of the microcontroller I / O port is configured to the interrupt input mode, and the overcurrent pulse line and signal output by the overcurrent detection circuit are transmitted to the I / O port of the microcontroller. When the overcurrent pulse line and signal are at a low level, an external interrupt request is generated. The recorded number of overcurrent pulse line and signal interruptions is compared with the limited number within a limited time range, and an enable / blocking signal for turning on or off the IGBT drive signal is output.

[0013] In order to prevent the microcontroller from responding to external overcurrent pulses multiple times in an interrupt manner during a switching cycle, the software method records the number of interruptions generated by the overcurrent pulse line and signal. If the number of overcurrent pulse line and signal interruptions recorded within a limited time range exceeds the limited number, the microcontroller outputs a control signal to block all IGBT drive signals of the inverter.

[0014] A software control algorithm for determining whether a motor has a continuous overcurrent, a short-term overcurrent, or a false overcurrent, specifically includes steps A to C.

[0015] Step A: When an external interrupt request is received in the current switching cycle, the external interrupt enable signal for the next switching cycle is disabled, a blocking signal for disabling the IGBT drive signal for the next switching cycle is output, the overcurrent time window counter is enabled and its value is incremented by 1, and the overcurrent pulse counter is enabled and its value is incremented by 1. The overcurrent time window counter is used to monitor the duration of overcurrent. When no external interrupt request occurs in the current switching cycle and the overcurrent time window counter is not enabled, an enable signal for enabling the IGBT drive signal for the next switching cycle is output. When no external interrupt request occurs in the current switching cycle but the overcurrent time window counter is enabled, the overcurrent time window counter is incremented by 1, and the process proceeds to step B. After the overcurrent time window counter is enabled, the overcurrent time window counter is incremented by 1 regardless of whether an external interrupt request occurs in the next switching cycle. The overcurrent pulse counter is incremented by 1 only when an external interrupt request occurs.

[0016] Step B: After the count value of the overcurrent time window counter is increased by 1, determine whether the count value of the overcurrent time window counter is greater than the overcurrent time window threshold A. The overcurrent time window threshold is used to limit a time range. The overcurrent time window threshold A is used to determine whether the overcurrent pulse line and the number of signal interruptions exceed the time range. If not, output an enable signal to turn on the IGBT drive signal for the next switching cycle, turn on the external interrupt enable signal for the next switching cycle, and the microcontroller enters the overcurrent detection judgment for the next switching cycle; if so, the value of the overcurrent time window counter is cleared and enters step C.

[0017] Step C: After the overcurrent time window counter is cleared, determine whether the overcurrent pulse counter value recorded within the time range specified by the overcurrent time window threshold A is greater than the overcurrent pulse count threshold B. The overcurrent pulse count threshold is used to filter out false overcurrent signals, where B≤A / 2. If not, it means that the motor has a short-term overcurrent or false overcurrent in the current switching cycle. The overcurrent pulse counter value is cleared, and an enable signal for turning on the IGBT drive signal for the next switching cycle is output, and the external interrupt enable signal for the next switching cycle is turned on. The microcontroller enters the overcurrent detection and judgment of the next switching cycle. If so, it means that the motor continues to overcurrent in the current switching cycle, and the external interrupt enable signal is continuously disabled, and a blocking signal is output to completely shut down all IGBT drive signals of the inverter.

[0018] An overcurrent protection circuit includes two logic AND gates. The first logic AND gate has two inputs connected to the output of an overcurrent detection circuit and a port that outputs an enable / block signal from a microcontroller, respectively, to receive an overcurrent pulse line AND signal and an enable / block signal. A second logic AND gate has one input connected to the output of the first logic AND gate, and its other input receives a five-phase PWM signal. The second logic AND gate outputs an IGBT drive signal. The five-phase PWM signal is generated through closed-loop feedback control based on the sampled values ​​of the AC input current of a five-phase permanent magnet synchronous motor.

[0019] The present invention adopts the above technical solution and has the following beneficial effects:

[0020] (1) The present invention uses a hardware overcurrent detection circuit to quickly block all IGBT drive signals of the inverter when the motor is overcurrent. The overcurrent detection circuit uses a "line and" method to simultaneously detect whether the five-phase current of the permanent magnet synchronous motor is overcurrent. This method is simple and reliable. Even in the case of phase loss operation, this method can achieve overcurrent protection and is suitable for various occasions where permanent magnet synchronous motors are working.

[0021] (2) In terms of software control algorithm, the present invention determines whether the overcurrent is continuous by judging the number of overcurrent pulses within a certain period of time. It can undisturbedly pass through short-term overcurrent or false overcurrent events, and protect the motor at the expense of a small amount of torque performance in the overcurrent state. It has a good anti-error protection mechanism.

[0022] (3) The present invention adopts an overcurrent control method that combines software and hardware. At the hardware level, the overcurrent detection circuit can quickly respond to overcurrent pulses and limit current in time with a relatively low circuit cost. At the software level, the software control algorithm can prevent erroneous operations caused by false overcurrent events, accurately judge the overcurrent signal, and prevent false protection. The accuracy of overcurrent protection is guaranteed while maintaining the speed of overcurrent protection, and the implementation is simple and reliable.

[0023] (4) The present invention can also change the response speed and sensitivity of the overcurrent protection by changing the preset parameters processed by the controller. The smaller the overcurrent time window threshold A is set, the faster the response speed of the overcurrent protection is, and the smaller the overcurrent pulse count threshold B is set, the higher the sensitivity of the overcurrent protection is. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a block diagram of the overcurrent protection control system of a five-phase permanent magnet synchronous motor.

[0025] Figure 2 This is a specific circuit diagram of a circuit for generating a reference level.

[0026] Figure 3 This is the specific circuit diagram of the overcurrent detection circuit.

[0027] Figure 4 It is a flow chart of the software control algorithm.

[0028] Figure 5 It is a specific circuit diagram of the overcurrent protection circuit.

[0029] Explanation of the numbers in the figure: R1 is the first resistor, R2 is the second resistor, C1 is the first capacitor, C2 is the second capacitor, U1A is the first logic AND gate, and U1B is the second logic AND gate. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings.

[0031] Figure 1 This is a block diagram of an overcurrent protection control system for a five-phase permanent magnet synchronous motor. The overcurrent protection control system for a five-phase permanent magnet synchronous motor includes: a power supply, a rectifier circuit, a five-phase inverter, an overcurrent detection circuit, a microcontroller, and an overcurrent protection circuit. The power supply is generally a 220V AC power supply, and the rectifier circuit converts the input AC power into DC power. The microcontroller outputs a PWM signal according to the instruction, which is then processed by the logic operation of the overcurrent protection circuit to generate an IGBT drive signal that controls the on and off of the IGBT in the five-phase inverter. The five-phase inverter outputs five-phase AC power, and the five-phase permanent magnet synchronous motor starts to operate after receiving the five-phase AC power. The overcurrent detection circuit detects whether the AC current of each phase of the five-phase permanent magnet synchronous motor is overcurrent. Once an overcurrent pulse occurs, it outputs an overcurrent pulse line and signal to the overcurrent protection circuit and sends an external interrupt request to the microcontroller, immediately shutting off the IGBT drive signal. When the AC current of the five-phase permanent magnet synchronous motor drops below the threshold, the IGBT drive signal will be turned on again. The microcontroller will record the number of overcurrent pulses after the first overcurrent signal appears. If the number of overcurrent pulses is sufficient within a preset time, the microcontroller will output a blocking signal to the overcurrent protection circuit, completely shutting off the IGBT drive signal.

[0032] See Figure 3 The overcurrent detection circuit's input is divided into five paths, each containing an overcurrent detection module that detects one phase of the five-phase permanent magnet synchronous motor's input AC current. The electrical component parameters of each overcurrent detection module are identical. Each overcurrent detection module includes a precision rectifier circuit, an EMI filter circuit, a comparator circuit, and a wired-AND output circuit.

[0033] The current sensor converts the AC current input to each phase of the motor into a voltage signal with an amplitude less than 3.3V. Generally, this signal is a sine wave. After passing through the precision rectifier circuit, the sine wave signal will be converted into a dual-pulse DC signal with a constant amplitude.

[0034] The dual-pulse DC signal passes through the EMI filter circuit, filtering out high-frequency interference. The EMI filter circuit consists of a first resistor R1, a first capacitor C1, and a second capacitor C2. One end of the first resistor R1 serves as the input of the EMI filter circuit. One end of the first capacitor C1 and one end of the second capacitor C2, connected to the other end of the first resistor R1, serve as the output of the EMI filter circuit. The other ends of the first capacitor C1 and the second capacitor C2 are both grounded.

[0035] The comparator circuit is implemented using the LM219D operational amplifier. The filtered dual-pulse DC signal is connected to the inverting input of the LM219D operational amplifier, and the reference voltage Uref is connected to the non-inverting input of the LM219D operational amplifier. The LM219D operational amplifier has an open-drain output, connected to an external second resistor R2 (i.e., a pull-up resistor) to a 3.3V level. When the amplitude of the dual-pulse DC signal is greater than the reference voltage Uref, the output of the LM219D operational amplifier is low; otherwise, it is high.

[0036] The outputs of the five overcurrent detection modules are connected together using a wired-AND logic circuit to form a common output. Under normal operation, the common output signal is high. If any of the overcurrent detection circuits detects an overcurrent, the common output signal drops to a low level, indicating that the overcurrent detection circuit has output an overcurrent signal. This method, by combining the five independent overcurrent pulse signals, can simultaneously detect overcurrent in all five paths, making it simple and reliable to implement.

[0037] The selection of the reference level Uref mentioned above can be found in Figure 2 In the figure, the +15V voltage can be provided by the power supply of the Hall current sensor. After being divided by the first resistor R1 and the second resistor R2, it is connected to the non-inverting input terminal of the operational amplifier LF353. The inverting input terminal of LF353 is directly connected to the output terminal, which plays the role of voltage follower. The reference level output by the output terminal The value of Uref is generally selected as 1.5 to 5 times the rated peak value of the CurtA signal. In this implementation, 1.5 times the rated peak value of the CurtA signal is selected, Uref = 1.65V. Then, according to the above formula, R1 = 2kΩ and R2 = 16kΩ are selected for voltage division.

[0038] See Figure 4 The software control algorithm used in this implementation is based on STM32f4. The IGBT switching frequency in the five-phase inverter is selected to be 10kHz, and the overcurrent time window is set to 500ms. An I / O port (such as PB5) of STM32f4 is configured as external interrupt mode. Figure 3 When the overcurrent signal OCurt is low (overcurrent state), an external interrupt is triggered. In the external interrupt service function, the external interrupt flag is cleared, the overcurrent flag is set to 1, and the IGBT drive signal is turned off to limit the current rise. At the same time, the external interrupt is disabled to avoid repeated external interrupt triggering and to allow sufficient time for the control algorithm in the PWM interrupt to calculate.

[0039] In the PWM interrupt service function, if the overcurrent flag is 1, the overcurrent flag is cleared, the overcurrent time window counter is enabled and incremented by 1, and the overcurrent pulse count is incremented by 1. If the overcurrent flag is 0, the IGBT drive signal and the external interrupt are enabled. Therefore, after an overcurrent signal occurs, the IGBT drive signal and external interrupt are disabled for the current switching cycle. They are not re-enabled until the PWM interrupt in the next switching cycle. This ensures that the external interrupt and IGBT drive signal are disabled for exactly one switching cycle.

[0040] Once the overcurrent time window counter is enabled, it increments by 1 with each PWM interrupt. Because the PWM interrupt is synchronized with the IGBT switching cycle, when the overcurrent time window counter reaches 5000 (i.e., 500ms after the first overcurrent signal), the PWM interrupt service function clears the overcurrent time window counter and checks whether the overcurrent pulse count is greater than 1000. Because each increment of the overcurrent pulse count disables the external interrupt enable for the next switching cycle, an overcurrent pulse is only recorded once every two switching cycles. In other words, within 500ms of an overcurrent event, the system checks whether the number of switching cycles in which the overcurrent event occurred has reached 2000. If the overcurrent pulse count does not reach 1000, it is considered a short-term overcurrent event (or false overcurrent event), and the overcurrent pulse count is cleared without disconnecting the power supply. If the number of overcurrent pulses reaches 1000, it is considered a continuous overcurrent. The PWM interrupt service function will turn off the IGBT drive signal and external interrupt, and set the continuous overcurrent protection flag to 1. In the next switching cycle, the PWM interrupt service function will no longer execute any of the above overcurrent protection related programs.

[0041] By changing the maximum value A of the overcurrent time window count, the response speed of the overcurrent protection can be changed; by changing the maximum value B of the overcurrent pulse count, the sensitivity of the overcurrent protection can be changed. Because the above rules of overcurrent time window count and overcurrent pulse count must meet B The above function can only be realized under the condition of A / 2. The most appropriate overcurrent protection preset parameters can be selected according to the requirements of motor operation in different occasions.

[0042] See Figure 5 ,when Figure 3 The output of the overcurrent pulse line and signal OCurt is low (overcurrent state), the output of the first logic "AND" gate U31A is low, and then it is combined with the five-phase PWM signal through the second logic "AND" gate U31B, and the output IGBT drive signal is low (overcurrent protection state). In this way, the control signal of the hardware circuit can quickly limit the motor current from continuing to rise. Similarly, when Figure 4When executing the task of turning off the IGBT drive signal for one switching cycle and completely shutting down the IGBT in the program flowchart, the level of the SoftProtect signal is lowered by software. After passing through the two-level logic "AND" gate, the output IGBT drive signal is a low level (overcurrent protection state).

[0043] This overcurrent protection circuit realizes the function of controlling the IGBT drive signal by combining hardware and software. The hardware circuit quickly performs current limiting processing on overcurrent phenomena, and the software algorithm accurately judges the overcurrent phenomenon to avoid false protection actions.

[0044] To sum up, the above embodiments are only illustrative of the present invention and do not limit its scope of protection. Those skilled in the art may also make partial changes thereto. For example, the number of modules included in the overcurrent detection circuit may be increased according to the number of phases of the multi-phase motor. Any form of equivalent replacement that complies with the purpose of the invention falls within the scope of protection of the present invention.

Claims

1. A five-phase permanent magnet synchronous motor overcurrent control method combining software and hardware, characterized in that: Detect the input AC current of the five-phase permanent magnet synchronous motor and obtain the overcurrent pulse line and signal when at least one phase of the input AC current is overcurrent; A microprocessor is used to obtain an overcurrent pulse line and signal in an external interrupt input mode, and a software algorithm is used to count overcurrent pulses within an overcurrent time window. When the overcurrent pulse count value recorded within the overcurrent time window exceeds a threshold, an enable / block signal is obtained. The enable / block signal controls the on or off of the inverter IGBT drive signal. The method of using a software algorithm to count overcurrent pulses within the overcurrent time window and obtaining an enable / block signal when the overcurrent pulse count value recorded within the overcurrent time window exceeds a threshold specifically includes the following steps: Step A: When an external interrupt request is received in the current switching cycle, the external interrupt enable signal of the next switching cycle is turned off, a blocking signal for turning off the IGBT drive signal of the next switching cycle is output, the overcurrent time window counter is turned on and its value is increased by 1, and the overcurrent pulse counter is turned on and its value is increased by 1; when no external interrupt request occurs in the current switching cycle and the overcurrent time window counter is not turned on, an enable signal for turning on the IGBT drive signal of the next switching cycle is output; when no external interrupt request occurs in the current switching cycle but the overcurrent time window counter is turned on, the overcurrent time window counter count value is increased by 1, and step B is entered. Step B: After the count value of the overcurrent time window counter is increased by 1, determine whether the count value of the overcurrent time window counter is greater than the overcurrent time window threshold A. If not, output the enable signal to start the IGBT drive signal of the next switching cycle, turn on the external interrupt enable signal of the next switching cycle, and the microcontroller enters the overcurrent detection judgment of the next switching cycle. If so, the value of the overcurrent time window counter is cleared and enter step C. Step C: After the overcurrent time window counter is cleared, determine whether the overcurrent pulse counter value recorded within the time range specified by the overcurrent time window threshold A is greater than the overcurrent pulse counting threshold B, B≤A / 2; if not, the overcurrent pulse counter value is cleared, an enable signal for starting the IGBT drive signal for the next switching cycle is output, the external interrupt enable signal for the next switching cycle is turned on, and the microcontroller enters the overcurrent detection and judgment for the next switching cycle; if so, the external interrupt enable signal is continuously disabled, and a blocking signal is output to completely shut down all IGBT drive signals of the inverter; Obtain the IGBT drive signal based on the overcurrent pulse line and signal, enable / block signal.

2. The five-phase permanent magnet synchronous motor overcurrent control method combining software and hardware according to claim 1 is characterized in that: An overcurrent detection circuit is used to detect the input AC current of a five-phase permanent magnet synchronous motor. The overcurrent detection circuit includes five detection modules and a "wired-AND" output circuit. Each detection module includes: a precision rectifier unit, an EMI filter unit, and a comparator with an open-drain output. The input end of the precision rectifier unit is connected to the input AC current of one phase of the five-phase permanent magnet synchronous motor, the input end of the EMI filter unit is connected to the output end of the precision rectifier unit, the output end of the EMI filter unit is connected to the inverting input end of the comparator, and the non-inverting input end of the comparator is connected to a reference voltage level. The output ends of the comparators in each detection module are connected in parallel and then connected to the "wired-AND" output circuit.

3. The five-phase permanent magnet synchronous motor overcurrent control method combining software and hardware according to claim 1 is characterized in that: An overcurrent protection circuit is used to obtain an IGBT overcurrent signal, and the overcurrent protection circuit includes: A first logic AND gate, wherein a first input terminal thereof is connected to an overcurrent pulse line AND signal, and a second input terminal thereof is connected to an enable / block signal; and The second logic AND gate has a first input terminal connected to the output terminal of the first logic AND gate, a second input terminal connected to the five-phase PWM signal, and outputs an IGBT driving signal.

4. The five-phase permanent magnet synchronous motor overcurrent control method combining software and hardware according to claim 2 is characterized in that: The EMI filter unit includes a first resistor, a first capacitor, and a second capacitor. One end of the first resistor is the input end of the EMI filter unit, one pole of the first capacitor, one pole of the second capacitor, and the other end of the first resistor are connected to serve as the output end of the EMI filter unit, and the other pole of the first capacitor and the other pole of the second capacitor are both grounded.

5. The five-phase permanent magnet synchronous motor overcurrent control method combining software and hardware according to claim 2 is characterized in that: The "wired-AND" output circuit includes a pull-up resistor and a third capacitor. One end of the pull-up resistor is connected to a DC level, and the other end of the pull-up resistor is connected to one electrode of the third capacitor to serve as the output end of the overcurrent detection circuit. The other electrode of the third capacitor is grounded.

6. The five-phase permanent magnet synchronous motor overcurrent control method combining software and hardware according to claim 2, characterized in that: The circuit for generating the reference level includes: a voltage divider circuit for dividing the power supply of a current sensor for obtaining the input AC current of a five-phase permanent magnet synchronous motor, and an operational amplifier. The input end of the voltage divider circuit is connected to the non-inverting input end of the operational amplifier, and the inverting input end of the operational amplifier is connected to the output end. The operational amplifier outputs a reference level, and the value of the reference level is 1.5 to 5 times the rated peak value of the five-phase permanent magnet synchronous motor input AC current sampling signal.

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