Power battery charging method, motor control circuit, and vehicle

Patent metadata

Field	Value
Publication number	US-2022077709-A1
Application number	US-201917416745-A
Country	US
Kind code	A1
Filing date	Dec 17, 2019
Priority date	Dec 21, 2018
Publication date	Mar 10, 2022
Grant date	—

Abstract

The present disclosure provides a power battery charging method, a motor control circuit, and a vehicle. The motor control circuit includes a first switch module, a three-phase inverter, and a control module, where a power supply module, the first switch module, the three-phase inverter, and a three-phase alternating current motor form a current loop, the three-phase alternating current motor inputs or outputs a current by using a wire N extending from a connection point of three phase coils, and the control module controls the three-phase inverter, so that the motor control circuit receives a voltage of the power supply module and outputs a direct current. In the technical solutions, a wire N extends from the three-phase alternating current motor, and further forms different charging loops with the three-phase inverter, the three-phase alternating current motor, and the power battery. When it is detected that the voltage of the power supply module is not higher than a voltage of the power battery, the original three-phase inverter and three-phase alternating current motor are adopted to boost the voltage of the power supply module before the power battery is charged, and in this way, no extra external boost circuit needs to be added, which reduces costs of the additional circuit.

First claim

1 . A motor control circuit, comprising:
a first switch module, a three-phase inverter, and a control module, wherein: a power supply module, the first switch module, the three-phase inverter, and a three-phase alternating current motor form a current loop, midpoints of three phase legs of the three-phase inverter are respectively connected to three phase coils of the three-phase alternating current motor, the three-phase alternating current motor inputs or outputs a current by using a wire N extending from a connection point of the three phase coils, the control module is separately connected to the three-phase inverter, the first switch module, the three-phase alternating current motor, and the power supply module, and the control module controls the three-phase inverter, so that the motor control circuit receives a voltage of the power supply module and outputs a direct current.

2 . The motor control circuit according to claim 1 , wherein:
the motor control circuit further comprises a second switch module, the three-phase inverter is connected to a power battery by the second switch module, and the second switch module is connected to the control module.

3 . The motor control circuit according to claim 2 , wherein:
a first terminal and a second terminal of the first switch module are connected to a positive electrode and a negative electrode of the power supply module, a third terminal of the first switch module is connected to the connection point of the three phase coils in the three-phase alternating current motor, a fourth terminal of the first switch module is connected to a second terminal of the three-phase inverter and a second terminal of the second switch module, a first terminal of the three-phase inverter is connected to a first terminal of the second switch module, and a third terminal and a fourth terminal of the second switch module are connected to a positive electrode and a negative electrode of the power battery.

4 . The motor control circuit according to claim 2 , wherein:
the first switch module comprises a first switch and a second switch, the second switch module comprises a third switch and a fourth switch, a first terminal and a second terminal of the first switch are respectively the first terminal and the third terminal of the first switch module, a first terminal and a second terminal of the second switch are respectively the second terminal and the fourth terminal of the first switch module, a first terminal and a second terminal of the third switch are respectively the first terminal and the third terminal of the second switch module, and a first terminal and a second terminal of the fourth switch are respectively the second terminal and the fourth terminal of the second switch module.

5 . The motor control circuit according to claim 1 , wherein:
the first switch module is the first switch, and the first switch is connected between the positive electrode of the power supply module and the connection point of the three phase coils of the three-phase alternating current motor; or
the first switch module is the second switch, and the second switch is connected between the negative electrode of the power supply module and the second terminal of the three-phase inverter.

6 . The motor control circuit according to claim 2 , wherein:
the second switch module is the third switch, and the third switch is connected between the first terminal of the three-phase inverter and the positive electrode of the power battery; or the second switch module is the fourth switch, and the fourth switch is connected between the second terminal of the three-phase inverter and the negative electrode of the power battery.

7 . A power battery charging method for a motor control circuit including a first switch module, a three-phase inverter, and a control module, wherein a power supply module, the first switch module, the three-phase inverter, and a three-phase alternating current motor form a current loop, midpoints of three phase legs of the three-phase inverter are respectively connected to three phase coils of the three-phase alternating current motor, the three-phase alternating current motor inputs or outputs a current by using a wire N extending from a connection point of the three phase coils, the control module is separately connected to the three-phase inverter, the first switch module, the three-phase alternating current motor, and the power supply module, and the control module controls the three-phase inverter, so that the motor control circuit receives a voltage of the power supply module and outputs a direct current, wherein the charging method comprises:
obtaining a voltage of the power supply module and a voltage of a power battery, and selecting a charging manner based on the voltage of the power supply module and the voltage of the power battery, wherein the charging manner comprises a boost charging manner and a direct charging manner; and controlling the first switch module to close so that the power supply module outputs a direct current, and controlling the three-phase inverter so that the power supply module charges the power battery in the selected charging manner.

8 . The power battery charging method according to claim 7 , wherein the selecting a charging manner based on the voltage of the power supply module and the voltage of the power battery comprises:
selecting the boost charging manner when it is detected that a highest output voltage of the power supply module is not higher than the voltage of the power battery, wherein the controlling the three-phase inverter so that the power supply module charges the power battery in the selected charging manner comprises: controlling the three-phase inverter so that a process of charging the three phase coils of the three-phase alternating current motor by the power supply module and a process of discharging the power battery by the power supply module and the three phase coils of the three-phase alternating current motor are alternately performed, to boost a charging voltage of the power supply module before the power battery is charged.

9 . The power battery charging method according to claim 8 , wherein the power supply module, the first switch module, the three-phase alternating current motor, and the three-phase inverter form a charging loop, and the power supply module, the first switch module, the three-phase alternating current motor, the three-phase inverter, and the power battery form a discharging loop; and
the controlling the three-phase inverter so that a process of charging the three phase coils of the three-phase alternating current motor by the power supply module and a process of discharging the power battery by the power supply module and the three phase coils of the three-phase alternating current motor are alternately performed comprises: controlling the three-phase inverter to perform alternate closing on the charging loop and the discharging loop.

10 . The power battery charging method according to claim 8 , wherein:
the three-phase inverter comprises three phase legs, each phase leg comprises two power switch units connected in series, and the three phase coils of the three-phase alternating current motor are separately connected to connection points of the two power switch units of the phase leg; and the controlling the three-phase inverter so that a process of charging the three phase coils of the three-phase alternating current motor by the power supply module and a process of discharging the power battery by the power supply module and the three phase coils of the three-phase alternating current motor are alternately performed comprises: controlling two power switch u

Assignees

• Byd Co Ltd

Inventors

• Liu Changjiu
• Pan Hua
• Ning Ronghua
• Liu Yang
• Yang Ning

Classifications

• H02J7/96 Primary

  in response to battery voltage · CPC title

• Y02T10/92

  Energy efficient charging or discharging systems for batteries, ultracapacitors, supercapacitors or double-layer capacitors specially adapted for vehicles · CPC title

• B60L53/22 Primary

  Constructional details or arrangements of charging converters specially adapted for charging electric vehicles · CPC title

• B60L15/20

  for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed · CPC title

• Y02T10/72

  Electric energy management in electromobility · CPC title