A trigger circuit, motor control system and vehicle

Abstract

The utility model discloses a kind of trigger circuit, motor control system and vehicle.The trigger circuit is applied to the switching bridge arm of control motor, and the trigger circuit includes: frequency conversion duty cycle module, for converting the first PWM signal input into second PWM signal;The first frequency of the first PWM signal is same with the frequency of motor's phase current signal, and the second PWM signal is signal with second duty cycle and same pulse width;Second duty cycle is associated with first frequency;Duty cycle conversion voltage module, the output of frequency conversion duty cycle module is electrically connected with the input of duty cycle conversion voltage module;Duty cycle conversion voltage module is for outputing trigger voltage signal corresponding to second duty cycle according to second PWM signal, to control the on-off switching of each switch tube in switching bridge arm according to trigger voltage signal.The trigger circuit, motor control system and vehicle provided by the utility model can improve trigger precision.

Description

Technical Field

[0001] This utility model relates to circuit technology, and more particularly to a trigger circuit, a motor control system, and a vehicle. Background Technology

[0002] Trigger circuits, such as those in vehicle motors, are used to control the motor's switching arm to prevent the vehicle from failing to enter a safe state when the motor speed is too high. Currently, the triggering accuracy of existing trigger circuits needs improvement. Utility Model Content

[0003] This utility model provides a triggering circuit, a motor control system, and a vehicle to improve triggering accuracy.

[0004] In a first aspect, this utility model embodiment provides a trigger circuit, which is used to control the switching arm of a motor, and the trigger circuit includes:

[0005] A frequency-to-duty cycle module is used to convert an input first PWM signal into a second PWM signal; the first frequency of the first PWM signal is the same as the frequency of the phase current signal of the motor, and the second PWM signal is a signal with a second duty cycle and the same pulse width; the second duty cycle is associated with the first frequency;

[0006] A duty cycle to voltage conversion module is provided, wherein the input terminal of the duty cycle to voltage conversion module is electrically connected to the output terminal of the frequency to duty cycle conversion module; the duty cycle to voltage conversion module is used to output a trigger voltage signal corresponding to the second duty cycle according to the second PWM signal, so as to control the on / off switching of each switching transistor in the switching bridge arm according to the trigger voltage signal.

[0007] Optionally, the frequency-to-duty cycle module includes an oscillator, a fourth resistor, and a first capacitor. The power supply terminal of the oscillator is connected to a power source through the fourth resistor and grounded through the first capacitor. The input terminal of the oscillator serves as the input terminal of the frequency-to-duty cycle module, and the output terminal of the oscillator serves as the output terminal of the frequency-to-duty cycle module.

[0008] Optionally, the pulse width and the voltage of the first capacitor, the fourth resistor, and the power supply satisfy the following relationship:

[0009] t H =K×R4×C1;

[0010] Among them, t H The pulse width corresponds to the time, K is a constant, R4 is the resistance of the fourth resistor, C1 is the capacitance of the first capacitor, and the value of K is related to the voltage of the first capacitor, the fourth resistor, and the power supply.

[0011] Optionally, the duty cycle of the second PWM signal is D, where D = t H / T=K×R4×C1×f, where the trigger voltage signal is D×VCC; where T is the period of the phase current signal, T=1 / f, f is the frequency of the phase current signal, and VCC is the voltage of the power supply.

[0012] Optionally, the duty cycle to voltage conversion module includes a second capacitor, a third capacitor, a fifth resistor, and a sixth resistor. The first terminal of the fifth resistor is the input terminal of the duty cycle to voltage conversion module. The second terminal of the fifth resistor is electrically connected to the first terminal of the sixth resistor. The first terminal of the sixth resistor is grounded through the second capacitor. The second terminal of the sixth resistor is grounded through the third capacitor. The second terminal of the sixth resistor is the output terminal of the duty cycle to voltage conversion module.

[0013] Optionally, the trigger circuit further includes a waveform conversion module, the output of which is electrically connected to the input of the frequency-to-duty cycle module; the input of the waveform conversion module is used to input a sine wave signal, and the waveform conversion module is used to convert the sine wave signal into the first PWM signal; the frequency of the sine wave signal is the same as the frequency of the phase current signal.

[0014] Optionally, the waveform conversion module includes a first comparator, a first resistor, and a second resistor; the resistance values ​​of the first resistor and the second resistor are the same; the non-inverting input terminal of the first comparator is connected to the power supply through the first resistor and grounded through the second resistor; the inverting input terminal of the first comparator receives the sine wave signal; the output terminal of the first comparator is connected to the power supply; and the output terminal of the first comparator is the output terminal of the waveform conversion module.

[0015] Optionally, the trigger circuit further includes a voltage comparison module. The input terminal of the voltage comparison module is electrically connected to the output terminal of the duty cycle to voltage conversion module. The voltage comparison module is used to compare the trigger voltage signal and a preset reference signal to obtain a trigger level signal and output it, so as to control the on / off switching of each switch in the switch bridge arm through the trigger level signal.

[0016] Optionally, the voltage comparison module includes a second comparator, a seventh resistor, an eighth resistor, and a ninth resistor. The non-inverting input terminal of the second comparator is connected to the power supply through the seventh resistor and grounded through the eighth resistor. It is also electrically connected to the output terminal of the second comparator through the ninth resistor. The inverting input terminal of the second comparator serves as the input terminal of the voltage comparison module. The output terminal of the second comparator is connected to the power supply and serves as the output terminal of the voltage comparison module.

[0017] Secondly, this utility model provides a motor control system, including a motor, a drive circuit, a switch bridge arm, and a trigger circuit as described in the first aspect. The trigger circuit, the drive circuit, the switch bridge arm, and the motor are electrically connected in sequence. The drive circuit is used to receive a trigger level signal transmitted by the trigger circuit and control the switching of each switch tube in the switch bridge arm according to the trigger level signal.

[0018] Thirdly, embodiments of the present invention provide a vehicle including the motor control system described in the second aspect.

[0019] The present invention provides a trigger circuit, a motor control system, and a vehicle. The trigger circuit is applied to control the switching arm of the motor. The trigger circuit includes: a frequency-to-duty cycle module for converting an input first PWM signal into a second PWM signal; the first frequency of the first PWM signal is the same as the frequency of the motor's phase current signal, and the second PWM signal is a signal with a second duty cycle and the same pulse width; the second duty cycle is associated with the first frequency; and a duty cycle-to-voltage module, the input terminal of which is electrically connected to the output terminal of the frequency-to-duty cycle module; the duty cycle-to-voltage module is used to output a trigger voltage signal corresponding to the second duty cycle according to the second PWM signal, so as to control the switching of each switching transistor in the switching arm according to the trigger voltage signal. The trigger circuit, motor control system, and vehicle provided in this embodiment convert a first PWM signal into a second PWM signal using a frequency-to-duty cycle module. The duty cycle of the second PWM signal is related to the frequency of the first PWM signal, and the pulse width of the second PWM signal is the same and fixed. The pulse width is not affected by other components in the circuit, which solves the problem in the prior art where direct frequency-to-voltage conversion results in low conversion accuracy due to the temperature of components such as diodes in the circuit. This improves the accuracy of the trigger voltage signal output by the duty cycle-to-voltage module, ensuring the accuracy of switching of each switch in the switch bridge arm according to the trigger voltage signal, thereby improving the trigger accuracy. Attached Figure Description

[0020] Figure 1 This is a structural block diagram of a trigger circuit provided in Embodiment 1 of this utility model;

[0021] Figure 2 This is a schematic diagram of a trigger circuit provided in Embodiment 1 of this utility model;

[0022] Figure 3 This is a structural block diagram of a trigger circuit provided in Embodiment 2 of this utility model. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0024] Example 1

[0025] Figure 1 This is a structural block diagram of a trigger circuit provided in Embodiment 1 of this utility model. Figure 2 This is a schematic diagram of a trigger circuit according to Embodiment 1 of this utility model. The trigger circuit is used to control the switching arm of a motor. (Refer to...) Figure 1 and Figure 2 The trigger circuit includes a frequency-to-duty cycle module 10 and a duty cycle-to-voltage module 20.

[0026] The frequency-to-duty cycle module 10 is used to convert the input first PWM signal into a second PWM signal. The first frequency of the first PWM signal is the same as the frequency of the phase current signal of the motor. The second PWM signal is a signal with a second duty cycle and the same pulse width. The second duty cycle is associated with the first frequency. The input terminal of the duty cycle-to-voltage module 20 is electrically connected to the output terminal of the frequency-to-duty cycle module 10. The duty cycle-to-voltage module 20 is used to output a trigger voltage signal corresponding to the second duty cycle according to the second PWM signal, so as to control the switching of each switch in the switch bridge arm according to the trigger voltage signal.

[0027] Specifically, the phase current signal of the motor can be converted into a voltage signal by a current sensor such as a Hall current sensor. The waveform of this voltage signal is a sine wave, and its frequency follows the frequency of the motor's phase current signal, meaning the frequency of the voltage signal is the same as the frequency of the motor's phase current signal. This sine wave voltage signal can be converted into a first PWM signal by a comparator. The frequency of the first PWM signal follows the frequency of this voltage signal, that is, the frequency of the first PWM signal follows the frequency of the motor's phase current signal, meaning the frequency of the first PWM signal is the same as the frequency of the motor's phase current signal. The first PWM signal is input to the input terminal of the frequency-to-duty cycle module 10, which converts the first PWM signal into a second PWM signal, such as outputting a fixed-width pulse signal on the rising edge of the first PWM signal to obtain the second PWM signal. Furthermore, the duty cycle of the second PWM signal is correlated with the frequency of the first PWM signal, thereby achieving the purpose of frequency-to-duty cycle conversion. The second PWM signal is input to the duty cycle-to-voltage module 20, which outputs a trigger voltage signal corresponding to the duty cycle of the second PWM signal. The duty cycle of the second PWM signal obtained by the frequency-to-duty cycle module 10 is related to the frequency of the first PWM signal. The pulse width of the second PWM signal is the same and fixed, and the pulse width is not affected by other components in the circuit. This prevents the problem of low conversion accuracy caused by the influence of components in the circuit when the frequency is directly converted to voltage. This improves the accuracy of the trigger voltage signal output by the duty cycle to voltage module 20 and ensures the accuracy of the switching of each switch in the switch bridge arm according to the trigger voltage signal.

[0028] The trigger circuit provided in this embodiment is applied to control the switching arm of a motor. The trigger circuit includes: a frequency-to-duty cycle module, used to convert the input first PWM signal into a second PWM signal; the first frequency of the first PWM signal is the same as the frequency of the motor's phase current signal, and the second PWM signal is a signal with a second duty cycle and the same pulse width; the second duty cycle is associated with the first frequency; a duty cycle-to-voltage module, the input terminal of which is electrically connected to the output terminal of the frequency-to-duty cycle module; the duty cycle-to-voltage module is used to output a trigger voltage signal corresponding to the second duty cycle according to the second PWM signal, so as to control the switching of each switching transistor in the switching arm according to the trigger voltage signal. The trigger circuit provided in this embodiment converts the first PWM signal into a second PWM signal through a frequency-to-duty cycle module. The duty cycle of the obtained second PWM signal is related to the frequency of the first PWM signal. The pulse width of the second PWM signal is the same and fixed, and the pulse width is not affected by other components in the circuit. This solves the problem in the prior art where direct frequency-to-voltage conversion results in low conversion accuracy due to the temperature of components in the circuit, such as diodes. This improves the accuracy of the trigger voltage signal output by the duty cycle-to-voltage module, ensuring the accuracy of controlling the switching of each switch in the switch bridge arm according to the trigger voltage signal, thereby improving the trigger accuracy.

[0029] Example 2

[0030] This embodiment is based on Embodiment 1. (See reference...) Figure 2 Optionally, the frequency-to-duty cycle module 10 includes an oscillator U0, a fourth resistor R4, and a first capacitor C1. The power supply terminal of the oscillator U0 is connected to the power supply through the fourth resistor R4 and grounded through the first capacitor C1. The input terminal of the oscillator U0 serves as the input terminal of the frequency-to-duty cycle module 10, and the output terminal of the oscillator U0 serves as the output terminal of the frequency-to-duty cycle module 10.

[0031] Specifically, the input of oscillator U0 receives the first PWM signal. When oscillator U0 detects the rising edge of the first PWM signal, it outputs a pulse signal of fixed width to form the second PWM signal. The duty cycle of the second PWM signal is related to the frequency of the first PWM signal, thus achieving the purpose of converting frequency to duty cycle. The time corresponding to the pulse width of the second PWM signal is related to the fourth resistor R4 and the first capacitor C1, which can be referred to in the subsequent description of the constant K.

[0032] For example, oscillator U0 is a monostable multivibrator, typically model 74HC123. A monostable multivibrator is an oscillator with both steady-state and metastable operating states. Compared to other oscillators such as astable multivibrators and crystal oscillators, it offers precise pulse width control: the main characteristic of a monostable multivibrator is its ability to generate precise and predictable pulse widths. By appropriately selecting the parameters of the components in the monostable multivibrator, such as the values ​​of resistors and capacitors, the duration of the output pulse can be precisely set. It also boasts high stability: the metastable time of a monostable multivibrator depends only on the circuit parameters and is relatively independent of external interference factors. If the power supply voltage and component parameters are stable, the monostable multivibrator can generate stable pulse signals, making it widely used in applications requiring high stability. Interference Resistance: Monostable multivibrators only enter a metastable state and generate output pulses when a trigger signal arrives. They remain stable and stationary without a trigger signal, unaffected by external noise or interference signals. This characteristic gives them good interference resistance in complex electromagnetic environments, ensuring reliable operation. Flexible Triggering Methods: Monostable multivibrators can employ various triggering methods, such as rising edge triggering, falling edge triggering, or level triggering. This allows for easy connection to different types of signal sources, adapting to various application scenarios and control requirements. Simple Circuit Structure: The circuit structure of a monostable multivibrator is relatively simple, typically consisting of a few basic electronic components such as transistors, resistors, and capacitors. This simple circuit structure not only reduces costs but also facilitates implementation and debugging, offering significant advantages in cost-sensitive and space-constrained applications.

[0033] Optionally, the pulse width and the voltage of the first capacitor C1, the fourth resistor R4, and the power supply satisfy the following relationship: t H =K×R4×C1; where, t H The pulse width corresponds to the time, K is a constant, R4 is the resistance of the fourth resistor, C1 is the capacitance of the first capacitor, and the value of K is related to the first capacitor C1, the fourth resistor R4, and the voltage VCC of the power supply.

[0034] Specifically, once the capacitance of the first capacitor C1, the resistance of the fourth resistor R4, and the power supply voltage VCC are determined, the value of K is also determined. Therefore, the value of K is only related to the first capacitor C1, the fourth resistor R4, and the power supply voltage VCC. Furthermore, according to the above formula t... H From K×R4×C1, we can know that the pulse width of the second PWM signal corresponds to the time t. H It depends only on K, the first capacitor C1, and the fourth resistor R4. Since the value of K depends only on the first capacitor C1, the fourth resistor R4, and the power supply voltage VCC, then time t... HThe pulse width of the second PWM signal is only related to the first capacitor C1, the fourth resistor R4, and the voltage VCC of the power supply. The pulse width is determined only by the passive components C1 and R4 and the power supply, which can keep the frequency of the phase current signal to voltage conversion error within 5% and ensure conversion accuracy.

[0035] Optionally, the duty cycle of the second PWM signal is D, where D = t H / T=K×R4×C1×f, the trigger voltage signal is D×VCC; where T is the period of the phase current signal, T=1 / f, f is the frequency of the phase current signal, and VCC is the voltage of the power supply.

[0036] Specifically, according to the formula for the duty cycle D of the second PWM signal, the duty cycle D of the second PWM signal is only related to K, R4, C1, and f. Since the value of K is only related to the first capacitor C1, the fourth resistor R4, and the power supply voltage VCC, once the capacitance value of the first capacitor C1, the resistance value of the fourth resistor R4, and the power supply voltage VCC are determined, the value of K is determined. The duty cycle D of the second PWM signal is only related to the frequency f of the phase current signal of the motor and is not affected by other components in the circuit, thus ensuring the accuracy of the duty cycle D of the second PWM signal.

[0037] Optionally, the duty cycle to voltage converter 20 includes a second capacitor C2, a third capacitor C3, a fifth resistor R5, and a sixth resistor R6. The first end of the fifth resistor R5 is the input terminal of the duty cycle to voltage converter 20. The second end of the fifth resistor R5 is electrically connected to the first end of the sixth resistor R6. The first end of the sixth resistor R6 is grounded through the second capacitor C2, and the second end of the sixth resistor R6 is grounded through the third capacitor C3. The second end of the sixth resistor R6 is the output terminal of the duty cycle to voltage converter 20.

[0038] The second capacitor C2, the third capacitor C3, the fifth resistor R5, and the sixth resistor R6 form a second-order low-pass filter to filter the AC component in the second PWM signal input to the duty cycle to voltage converter 20, retaining only the DC component. The trigger voltage signal output from the output terminal of the duty cycle to voltage converter 20 is D×VCC, i.e., K×R4×C1×f×VCC, where K, R4, C1, and VCC are all constants. Thus, the frequency of the first PWM signal, the frequency of the phase current signal, and the trigger voltage signal correspond one-to-one.

[0039] Figure 3 This is a structural block diagram of a trigger circuit provided in Embodiment 2 of this utility model. (Reference) Figure 3Optionally, the trigger circuit also includes a waveform conversion module 30, the output of which is electrically connected to the input of the frequency-to-duty cycle module 20; the input of the waveform conversion module 30 is used to input a sine wave signal, and the waveform conversion module 30 is used to convert the sine wave signal into a first PWM signal; the frequency of the sine wave signal is the same as the frequency of the phase current signal.

[0040] The sinusoidal signal can be a voltage signal output by a current sensor such as a Hall current sensor. The input of the Hall current sensor is the phase current signal of the motor, and the output of the Hall current sensor is a voltage signal. The frequency of the voltage signal follows the frequency of the phase current signal, meaning the frequency of the sinusoidal signal follows the frequency of the phase current signal, and the frequency of the sinusoidal signal is the same as the frequency of the phase current signal. The sinusoidal signal is converted into a first PWM signal by the waveform conversion module 30. The duty cycle of the first PWM signal is fixed, and the frequency of the first PWM signal follows the frequency of the sinusoidal signal, meaning the frequency of the first PWM signal is the same as the frequency of the phase current signal, thus completing the conversion of the sinusoidal signal to a PWM signal. Furthermore, the first PWM signal retains only the frequency of the phase current signal.

[0041] refer to Figure 2 and Figure 3 Optionally, the waveform conversion module 30 includes a first comparator U1, a first resistor R1, and a second resistor R2; the resistance value of the first resistor R1 is the same as the resistance value of the second resistor R2. The non-inverting input terminal of the first comparator U1 is connected to the power supply through the first resistor R1 and grounded through the second resistor R2. The inverting input terminal of the first comparator U1 receives a sine wave signal. The output terminal of the first comparator U1 is connected to the power supply and is the output terminal of the waveform conversion module 30.

[0042] For example, the expression for the sine wave signal is Ip×G+1 / 2×VCC, where Ip is the phase current signal of the motor, VCC is the voltage of the power supply, G is the gain of the Hall current sensor, and G is a constant; the model of the Hall current sensor determines G. The resistance values ​​of the first resistor R1 and the second resistor R2 are the same, ensuring that the voltage input to the non-inverting input terminal of the first comparator U1 is 1 / 2×VCC. When the voltage input to the non-inverting input terminal of the first comparator U1 is greater than the voltage input to the inverting input terminal of the first comparator U1, the output voltage of the first comparator U1 is the power supply voltage VCC. When the voltage input to the non-inverting input terminal of the first comparator U1 is less than the voltage input to the inverting input terminal of the first comparator U1, the output voltage of the first comparator U1 is zero. That is, the high level of the first PWM signal is the power supply voltage VCC, and the low voltage is 0V. The duty cycle of the first PWM signal is 50%, thus completing the conversion of the sine wave signal to a PWM signal, and the first PWM signal only retains the frequency of the phase current signal.

[0043] In addition, the trigger circuit also includes a third resistor R3 and a Hall current sensor U3. The output of the first comparator U1 is connected to the power supply through the third resistor R3, which acts as a pull-up resistor. The output of the Hall current sensor U3 is electrically connected to the inverting input of the first comparator U1. The signal output by the Hall current sensor U3 is a sinusoidal voltage signal Vin, Vin = Ip × G + 1 / 2 × VCC, where Ip is the phase current signal of the motor, G is the gain of the Hall current sensor, and the voltage signal Vin varies around 1 / 2 × VCC. The frequency of this voltage signal follows the frequency f of the phase current signal. Where n is the motor speed in rpm, and P is the number of pole pairs of the motor.

[0044] refer to Figure 3 Optionally, the trigger circuit also includes a voltage comparison module 40. The input terminal of the voltage comparison module 40 is electrically connected to the output terminal of the duty cycle to voltage conversion module 20. The voltage comparison module 40 is used to compare the trigger voltage signal and the preset reference signal to obtain the trigger level signal and output it, so as to control the switching of each switch in the switch bridge arm through the trigger level signal.

[0045] The preset reference signal is a voltage signal, which can be the power supply voltage VCC. For example, when the voltage of the trigger voltage signal is greater than the voltage of the preset reference signal, the voltage comparison module 40 outputs a low-level signal; when the voltage of the trigger voltage signal is less than the voltage of the preset reference signal, the voltage comparison module 40 outputs a high-level signal. The switching of each switch in the switch bridge arm is controlled according to the level signal output by the voltage comparison module 40, i.e., the trigger level signal.

[0046] refer to Figure 2 and Figure 3 Optionally, the voltage comparison module 40 includes a second comparator U2, a seventh resistor R7, an eighth resistor R8, and a ninth resistor R9. The non-inverting input terminal of the second comparator U2 is connected to the power supply through the seventh resistor R7 and grounded through the eighth resistor R8. It is also electrically connected to the output terminal of the second comparator U2 through the ninth resistor R9. The inverting input terminal of the second comparator U2 serves as the input terminal of the voltage comparison module 40. The output terminal of the second comparator U2 is connected to the power supply through the tenth resistor R10, and the output terminal of the second comparator U2 serves as the output terminal of the voltage comparison module 40.

[0047] In this design, the seventh resistor R7 and the eighth resistor R8 form a resistor divider to set the comparison reference voltage, i.e., the voltage of the preset reference signal. The ninth resistor R9 prevents hysteresis, i.e., prevents the voltage comparison module 40's output level signal from fluctuating around the preset reference signal. Specifically, the voltage at the non-inverting input of the second comparator U2 is the power supply voltage VCC, and the voltage at the inverting input of the second comparator U2 is the trigger voltage signal. When the voltage at the non-inverting input of the second comparator U2 is greater than the voltage at the inverting input of the second comparator U2, the output of the second comparator U2 outputs a high-level signal, the voltage of which is VCC. When the voltage at the non-inverting input of the second comparator U2 is less than the voltage at the inverting input of the second comparator U2, the output of the second comparator U2 outputs a low-level signal, the voltage of which is the trigger voltage signal. The switching of each switch in the switching bridge arm is achieved based on the level signal output by the second comparator U2, i.e., the trigger level signal.

[0048] Furthermore, the voltage comparison module 40 also includes a tenth resistor R10. The output terminal of the second comparator U2 is connected to the power supply through the tenth resistor R10, which acts as a pull-up resistor.

[0049] The trigger circuit provided in this embodiment is applied to control the switching arm of a motor. The trigger circuit includes: a frequency-to-duty-cycle module for converting an input first PWM signal into a second PWM signal; the first frequency of the first PWM signal is the same as the frequency of the motor's phase current signal; the second PWM signal is a signal with a second duty cycle and the same pulse width; the second duty cycle is associated with the first frequency; and a duty cycle-to-voltage module, the input terminal of which is electrically connected to the output terminal of the frequency-to-duty-cycle module; the duty cycle-to-voltage module is used to output a trigger voltage signal corresponding to the second duty cycle based on the second PWM signal, so as to trigger the voltage... The circuit control system controls the switching of each transistor in the switching bridge arm. It also includes a waveform conversion module and a voltage comparison module. The output of the waveform conversion module is electrically connected to the input of the frequency-to-duty cycle module, and the input of the voltage comparison module is electrically connected to the output of the duty cycle-to-voltage module. The voltage comparison module compares the trigger voltage signal with a preset reference signal to obtain a trigger level signal and outputs it, thereby controlling the switching of each transistor in the switching bridge arm. The frequency-to-duty cycle module includes an oscillator, a fourth resistor, and a first capacitor. The power supply terminal of the oscillator is connected to the power supply through the fourth resistor and grounded through the first capacitor. The input terminal of the oscillator... The input and output terminals are respectively used as the input and output terminals of the frequency-to-duty cycle module; the duty cycle-to-voltage module includes a second capacitor, a third capacitor, a fifth resistor, and a sixth resistor. The first terminal of the fifth resistor is the input terminal of the duty cycle-to-voltage module, the second terminal of the fifth resistor is electrically connected to the first terminal of the sixth resistor, the first terminal of the sixth resistor is grounded through the second capacitor, the second terminal of the sixth resistor is grounded through the third capacitor, and the second terminal of the sixth resistor is the output terminal of the duty cycle-to-voltage module; the waveform conversion module includes a first comparator, a first resistor, a second resistor, and a third resistor; the non-inverting input terminal of the first comparator is connected to the power supply through the first resistor and connected to the power supply through the second resistor. The first comparator receives a sine wave signal at its inverting input terminal and its output terminal is connected to the power supply via a third resistor. The output terminal of the first comparator is also the output terminal of the waveform conversion module. The voltage comparison module includes a second comparator, a seventh resistor, an eighth resistor, a ninth resistor, and a tenth resistor. The non-inverting input terminal of the second comparator is connected to the power supply via the seventh resistor and grounded via the eighth resistor. It is also electrically connected to the output terminal of the second comparator via the ninth resistor. The inverting input terminal of the second comparator serves as the input terminal of the voltage comparison module. The output terminal of the second comparator is connected to the power supply via the tenth resistor and is also the output terminal of the voltage comparison module.The trigger circuit provided in this embodiment converts the first PWM signal into a second PWM signal through the first comparator in the frequency-to-duty cycle module. The duty cycle of the obtained second PWM signal is related to the frequency of the first PWM signal. The pulse width of the second PWM signal is the same and fixed. The pulse width is determined only by the passive components, the fourth resistor and the first capacitor, and the power supply, and is not affected by other components in the circuit. This solves the problem in the prior art where the direct frequency-to-voltage conversion results in low conversion accuracy due to the temperature of components in the circuit, such as diodes. This improves the accuracy of the trigger voltage signal output by the second comparator in the duty cycle-to-voltage module, ensuring the accuracy of controlling the switching of each switch in the switch bridge arm according to the trigger voltage signal, thereby improving the trigger accuracy.

[0050] This embodiment also provides a motor control system, including a motor, a drive circuit, a switch bridge arm, and a trigger circuit as described in any embodiment of this utility model. The trigger circuit, drive circuit, switch bridge arm, and motor are electrically connected in sequence. The drive circuit is used to receive the trigger level signal transmitted by the trigger circuit and control the switching of each switch in the switch bridge arm according to the trigger level signal.

[0051] This embodiment also provides a vehicle including a motor control system as described in any embodiment of this utility model.

[0052] The motor control system and vehicle provided in this embodiment belong to the same inventive concept as the trigger circuit provided in any embodiment of this utility model, and have corresponding beneficial effects. For technical details not detailed in this embodiment, please refer to the trigger circuit provided in any embodiment of this utility model.

[0053] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, combinations, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. A trigger circuit, characterized in that, The trigger circuit is used to control the switching arm of the motor, and the trigger circuit includes: A frequency-to-duty cycle module is used to convert an input first PWM signal into a second PWM signal; the first frequency of the first PWM signal is the same as the frequency of the phase current signal of the motor, and the second PWM signal is a signal with a second duty cycle and the same pulse width; the second duty cycle is associated with the first frequency; A duty cycle to voltage conversion module is provided, wherein the input terminal of the duty cycle to voltage conversion module is electrically connected to the output terminal of the frequency to duty cycle conversion module; the duty cycle to voltage conversion module is used to output a trigger voltage signal corresponding to the second duty cycle according to the second PWM signal, so as to control the on / off switching of each switching transistor in the switching bridge arm according to the trigger voltage signal.

2. The trigger circuit according to claim 1, characterized in that, The frequency-to-duty cycle module includes an oscillator, a fourth resistor, and a first capacitor. The power supply terminal of the oscillator is connected to a power source through the fourth resistor and grounded through the first capacitor. The input terminal of the oscillator serves as the input terminal of the frequency-to-duty cycle module, and the output terminal of the oscillator serves as the output terminal of the frequency-to-duty cycle module.

3. The trigger circuit according to claim 2, characterized in that, The pulse width and the voltage of the first capacitor, the fourth resistor, and the power supply satisfy the following relationship: t H =K×R4×C1; Among them, t H The pulse width corresponds to the time, K is a constant, R4 is the resistance of the fourth resistor, C1 is the capacitance of the first capacitor, and the value of K is related to the voltage of the first capacitor, the fourth resistor, and the power supply.

4. The trigger circuit according to claim 3, characterized in that, The duty cycle of the second PWM signal is D, where D = t H / T=K×R4×C1×f, where the trigger voltage signal is D×VCC; where T is the period of the phase current signal, T=1 / f, f is the frequency of the phase current signal, and VCC is the voltage of the power supply.

5. The trigger circuit according to claim 1, characterized in that, The duty cycle to voltage conversion module includes a second capacitor, a third capacitor, a fifth resistor, and a sixth resistor. The first terminal of the fifth resistor is the input terminal of the duty cycle to voltage conversion module. The second terminal of the fifth resistor is electrically connected to the first terminal of the sixth resistor. The first terminal of the sixth resistor is grounded through the second capacitor, and the second terminal of the sixth resistor is grounded through the third capacitor. The second terminal of the sixth resistor is the output terminal of the duty cycle to voltage conversion module.

6. The trigger circuit according to claim 1, characterized in that, It also includes a waveform conversion module, the output of which is electrically connected to the input of the frequency-to-duty cycle module; the input of the waveform conversion module is used to input a sine wave signal, and the waveform conversion module is used to convert the sine wave signal into the first PWM signal; the frequency of the sine wave signal is the same as the frequency of the phase current signal.

7. The trigger circuit according to claim 6, characterized in that, The waveform conversion module includes a first comparator, a first resistor, and a second resistor. The resistance values ​​of the first resistor and the second resistor are the same. The non-inverting input terminal of the first comparator is connected to the power supply through the first resistor and grounded through the second resistor. The inverting input terminal of the first comparator receives the sine wave signal. The output terminal of the first comparator is connected to the power supply. The output terminal of the first comparator is the output terminal of the waveform conversion module.

8. The trigger circuit according to claim 1, characterized in that, It also includes a voltage comparison module, the input of which is electrically connected to the output of the duty cycle to voltage conversion module. The voltage comparison module is used to compare the trigger voltage signal and the preset reference signal to obtain a trigger level signal and output it, so as to control the on / off switching of each switch in the switch bridge arm through the trigger level signal.

9. The trigger circuit according to claim 8, characterized in that, The voltage comparison module includes a second comparator, a seventh resistor, an eighth resistor, and a ninth resistor. The non-inverting input terminal of the second comparator is connected to the power supply through the seventh resistor and grounded through the eighth resistor. It is also electrically connected to the output terminal of the second comparator through the ninth resistor. The inverting input terminal of the second comparator serves as the input terminal of the voltage comparison module. The output terminal of the second comparator is connected to the power supply and serves as the output terminal of the voltage comparison module.

10. A motor control system, characterized in that, The device includes a motor, a drive circuit, and a switch bridge arm, and further includes a trigger circuit as described in any one of claims 1-9, wherein the trigger circuit, the drive circuit, the switch bridge arm, and the motor are electrically connected in sequence; the drive circuit is used to receive a trigger level signal transmitted by the trigger circuit, and to control the switching of each switch in the switch bridge arm according to the trigger level signal.

11. A vehicle, characterized in that, Including the motor control system as described in claim 10.

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