CN-121984339-A - Transient high-voltage peak elimination circuit and method for motor drive circuit

CN121984339ACN 121984339 ACN121984339 ACN 121984339ACN-121984339-A

Abstract

The application relates to a motor drive circuit transient high-voltage peak elimination circuit and a method, wherein the circuit comprises a step-down chopper circuit, a freewheel circuit, an energy storage circuit, a motor voltage peak elimination circuit, a three-phase upper bridge drive circuit, a three-phase lower bridge drive circuit and a current sampling circuit, wherein the two ends of the freewheel circuit are connected with a first peak elimination circuit in parallel, the two ends of each drive circuit are respectively connected with a second peak elimination circuit in parallel, the chopper circuit is used for controlling motor voltage, the freewheel circuit is used for providing a current freewheel circuit, each peak elimination circuit is respectively used for reducing peak voltage of a corresponding circuit, when the motor works in a motor mode, current flows from the positive electrode of an external power supply, sequentially flows through the step-down chopper circuit, the energy storage circuit and the upper bridge drive circuit and then enters the motor, flows from the motor, sequentially flows back to the ground after flowing out of the motor after sequentially flowing through the lower bridge drive circuit and the current sampling circuit, and flows back to the motor after flowing through the lower bridge drive circuit, the current sampling circuit and the energy storage circuit and the upper bridge drive circuit when the motor works in a generator mode. The application can reduce the voltage peak of the motor driving circuit.

Inventors

ZHANG PENGBO
YANG JIGANG
HE SHI
LI JIANPU
Guo tengfei
ZHANG JIYANG
LIU XINYAN
GUO XING
QI MING
YANG YI
WEI WENSHAN
HU YUEWEI
HE YONG

Assignees

北京控制工程研究所

Dates

Publication Date: 20260505
Application Date: 20260130

Claims (10)

1. The transient high-voltage peak elimination circuit of the motor drive circuit is characterized by comprising a step-down chopper circuit, a follow current circuit, a power storage circuit, a motor voltage peak elimination circuit, a three-phase upper bridge drive circuit, a three-phase lower bridge drive circuit and a current sampling circuit; The motor drive circuit comprises a motor, a follow current circuit, a motor voltage peak eliminating circuit and a motor voltage peak eliminating circuit, wherein the two ends of the follow current circuit are connected in parallel with the first peak eliminating circuit, the two ends of each drive circuit are respectively connected in parallel with the second peak eliminating circuit, the chopper circuit is used for controlling motor voltage, the follow current circuit is used for providing a current follow current path when the chopper circuit is turned off, the first peak eliminating circuit is used for reducing peak voltage in the switching process of the chopper circuit, the motor voltage peak eliminating circuit is used for reducing peak voltage of motor supply voltage, and each second peak eliminating circuit is respectively used for reducing peak voltage at the two ends of the corresponding drive circuit; When the motor works in a motor mode, current sequentially flows through the step-down chopper circuit, the energy storage circuit and the upper bridge driving circuit from the positive electrode of an external power supply, then enters the motor, flows out of the motor, sequentially flows through the lower bridge driving circuit and the current sampling circuit and then flows back to the ground; When the motor works in a generator mode, current flows out from the motor, and flows back to the motor after passing through the lower bridge driving circuit, the current sampling circuit, the follow current circuit, the energy storage circuit and the upper bridge driving circuit.
2. The motor drive circuit transient high voltage peak elimination circuit according to claim 1, wherein the step-down chopper circuit comprises a first power tube, a chopper tube, a first resistor and a second resistor; One end of the first power tube is connected with the positive electrode of an external power supply, the other end of the first power tube is connected with one end of the chopper tube, and the other end of the chopper tube is connected with the energy storage circuit; the first power tube is used for switching the motor between a motor mode and a generator mode, and an input signal of the chopper tube is a PWM signal so as to adjust the voltage of the motor based on the PWM signal.
3. The motor drive circuit transient high voltage peak elimination circuit according to claim 2, wherein the follow current circuit comprises a diode and a second power tube, wherein the cathode of the diode is connected with the outlet end of the chopper tube, the other end of the diode is connected with one end of the second power tube, the other end of the second power tube is grounded, and the second power tube is used for controlling the current of the follow current circuit.
4. A motor drive circuit transient high voltage peak elimination circuit according to claim 3, wherein said first peak elimination circuit comprises a first peak elimination unit, said first peak elimination unit comprises a capacitor and a resistor, and said capacitor and said resistor are connected in series and then connected in parallel with said freewheel circuit to eliminate voltage fluctuations of the freewheel circuit.
5. The motor drive circuit transient high voltage peak elimination circuit according to claim 4, wherein said first peak elimination circuit further comprises a second peak elimination unit, said second peak elimination unit comprises a diode, and said diode is connected in parallel with said freewheel circuit for absorbing excessive electric energy when the voltage value of the freewheel circuit exceeds a set threshold.
6. The motor drive circuit transient high voltage peak elimination circuit according to claim 2, wherein the motor voltage peak elimination circuit comprises a differential mode filter unit and a common mode filter unit, wherein one ends of the differential mode filter unit and the common mode filter unit are respectively connected with a circuit between the energy storage circuit and the upper bridge drive circuit, and the other ends of the differential mode filter unit and the common mode filter unit are respectively grounded; the differential mode filter unit at least comprises two capacitors connected in series and is used for reducing differential mode pressure difference between two lines; The common mode filter unit at least comprises two capacitors and a resistor which are connected in series, one end of the resistor is connected between the two capacitors, and the other end of the resistor is connected with the shell, so that common mode voltage difference caused by the ground is reduced.
7. The motor drive circuit transient high voltage peak elimination circuit according to claim 1, wherein each of said drive circuits comprises a power tube when the motor voltage is always higher than the counter potential of the motor, whereas each of said drive circuits further comprises a diode, and said power tube and said diode are connected in series.
8. The motor drive circuit transient high voltage peak elimination circuit according to claim 1, wherein each of said second peak elimination circuits comprises a third peak elimination unit, each of said third peak elimination units comprises a capacitor and a resistor, and said capacitor and said resistor are connected in series and then connected in parallel with the corresponding drive circuit to eliminate voltage fluctuation of the corresponding drive circuit.
9. The motor drive circuit transient high voltage peak elimination circuit according to claim 8, wherein each of said second peak elimination circuits further comprises a fourth peak elimination unit, each of said fourth peak elimination units comprises a diode, and said diode is connected in parallel with the corresponding drive circuit for absorbing excessive electric energy when the voltage value of the drive circuit exceeds a set threshold value.
10. A motor drive circuit transient high voltage peak elimination method applied to the motor drive circuit transient high voltage peak elimination circuit according to any one of claims 1 to 9, comprising: Controlling a motor voltage by using the chopper circuit; When the chopper circuit is turned off, providing a current freewheel path by using the freewheel circuit, and reducing peak voltage in the switching process of the chopper circuit by using the first peak elimination circuit; the peak voltage of the motor power supply voltage is reduced by using the motor voltage peak eliminating circuit; and reducing peak voltages at two ends of the corresponding driving circuit by using each second peak eliminating circuit.

Description

Transient high-voltage peak elimination circuit and method for motor drive circuit Technical Field The invention relates to the technical field of electronic circuits, in particular to a motor drive circuit transient high-voltage peak elimination circuit and a motor drive circuit transient high-voltage peak elimination method. Background Because the motor has inductance, the buck circuit in the motor driving circuit has inductance and the like, when the motor commutates and the circuit switching tube works, voltage spikes can be generated due to abrupt on-off of current. The peak gradually increases along with the increase of the counter potential coefficient of the motor, the increase of the rotating speed and the increase of the working current, and if the motor is not controlled, the voltage peak may exceed hundreds of volts or even kilovolts, so that the components of the driving circuit are damaged. In view of the foregoing, a circuit and a method for reducing voltage spikes of a motor driving circuit are needed to solve the above-mentioned problems. Disclosure of Invention The embodiment of the invention provides a transient high-voltage peak elimination circuit and a transient high-voltage peak elimination method for a motor driving circuit, which can reduce voltage peaks of the motor driving circuit, reduce working voltage of devices and improve reliability of products. In a first aspect, an embodiment of the present invention provides a motor driving circuit transient high voltage peak elimination circuit, including: the motor comprises a step-down chopper circuit, a follow current circuit, a tank circuit, a motor voltage peak elimination circuit, a three-phase upper bridge driving circuit, a three-phase lower bridge driving circuit and a current sampling circuit; The motor drive circuit comprises a motor, a follow current circuit, a motor voltage peak eliminating circuit and a motor voltage peak eliminating circuit, wherein the two ends of the follow current circuit are connected in parallel with the first peak eliminating circuit, the two ends of each drive circuit are respectively connected in parallel with the second peak eliminating circuit, the chopper circuit is used for controlling motor voltage, the follow current circuit is used for providing a current follow current path when the chopper circuit is turned off, the first peak eliminating circuit is used for reducing peak voltage in the switching process of the chopper circuit, the motor voltage peak eliminating circuit is used for reducing peak voltage of motor supply voltage, and each second peak eliminating circuit is respectively used for reducing peak voltage at the two ends of the corresponding drive circuit; When the motor works in a motor mode, current sequentially flows through the step-down chopper circuit, the energy storage circuit and the upper bridge driving circuit from the positive electrode of an external power supply, then enters the motor, flows out of the motor, sequentially flows through the lower bridge driving circuit and the current sampling circuit and then flows back to the ground; When the motor works in a generator mode, current flows out from the motor, and flows back to the motor after passing through the lower bridge driving circuit, the current sampling circuit, the follow current circuit, the energy storage circuit and the upper bridge driving circuit. In one possible design, the buck chopper circuit includes a first power tube, a chopper tube, a first resistor, and a second resistor; One end of the first power tube is connected with the positive electrode of an external power supply, the other end of the first power tube is connected with one end of the chopper tube, and the other end of the chopper tube is connected with the energy storage circuit; the first power tube is used for switching the motor between a motor mode and a generator mode, and an input signal of the chopper tube is a PWM signal so as to adjust the voltage of the motor based on the PWM signal. In one possible design, the freewheeling circuit comprises a diode and a second power tube, wherein the cathode of the diode is connected with the outlet end of the chopper tube, the other end of the diode is connected with one end of the second power tube, the other end of the second power tube is grounded, and the second power tube is used for controlling the current of the freewheeling circuit. In one possible design, the first peak-canceling circuit includes a first peak-canceling unit, the first peak-canceling unit includes a capacitor and a resistor, and the capacitor and the resistor are connected in series and then connected in parallel to the flywheel circuit to cancel voltage fluctuations of the flywheel circuit. In one possible design, the first peak-canceling circuit further includes a second peak-canceling unit, and the second peak-canceling unit includes a diode connected in parallel with the flywheel circuit for absorbing the surplu