CN-119795926-B - Implementation method and system of electric retarder

CN119795926BCN 119795926 BCN119795926 BCN 119795926BCN-119795926-B

Abstract

The application relates to an implementation method and a system of an electric retarder, wherein the implementation method comprises the steps of requesting braking power generation torque to be transmitted to a motor controller through a whole-vehicle-domain controller when a brake pedal is triggered, traversing a target lookup table based on the power generation torque to obtain target direct-axis current and target quadrature-axis current of a permanent magnet synchronous motor, performing energy conversion on the target direct-axis current and the target quadrature-axis current based on the motor controller, and distributing the converted energy to a motor and a battery system, and obtaining new target direct-axis current and new target quadrature-axis current of the permanent magnet synchronous motor based on the target lookup table when the voltage in the battery exceeds a preset value, and distributing the new target direct-axis current and the new target quadrature-axis current to reduce the voltage in the battery system. The application timely converts braking force into heat to consume, reduces energy recovery and reduces abrasion of mechanical brake.

Inventors

ZHANG MINYAN
XIE LINGYU
XU XUEHAI

Assignees

无锡蓝海华腾技术有限公司

Dates

Publication Date: 20260508
Application Date: 20231009

Claims (8)

1. A method of implementing an electric retarder, comprising: when the brake pedal is triggered, requesting braking power generation torque to be transmitted to the motor controller through the whole-vehicle-domain controller; Constructing a maximum torque curve and an equal torque curve based on a torque equation of the embedded permanent magnet synchronous motor; Constructing an equal current circle based on a voltage equation of the permanent magnet synchronous motor in a steady state; constructing a target lookup table of the corresponding relation between the torque and the current based on the maximum torque curve, the equal torque curve and the equal current circle; Traversing the target lookup table based on the generated torque to obtain target direct axis current and target quadrature axis current of the permanent magnet synchronous motor; performing energy conversion on the target direct-axis current and the target quadrature-axis current based on the motor controller, and distributing the converted energy to a motor and a battery system; When the voltage in the battery exceeds a preset value, acquiring a new target direct-axis current and a new target quadrature-axis current of the permanent magnet synchronous motor based on the target lookup table, and distributing the new target direct-axis current and the new target quadrature-axis current to reduce the charging energy in the battery system; When the voltage in the battery exceeds a preset value, acquiring a new target direct-axis current and a new target quadrature-axis current of the permanent magnet synchronous motor based on the target lookup table, and distributing the new target direct-axis current and the new target quadrature-axis current to reduce the charging energy in the battery system, wherein the method comprises the following steps: when the voltage in the battery exceeds a preset value, requesting braking of the power generation torque to be transmitted to the motor controller through the whole-vehicle-domain controller; Traversing the target lookup table through the motor controller to obtain a target position point, which is only intersected with the equal current circle, of an equal torque curve corresponding to the power generation torque, and obtain the new target straight-axis current and the new target quadrature-axis current corresponding to the target position point; and performing energy conversion on the new target direct-axis current and the new target quadrature-axis current based on the motor controller, and distributing the converted energy to the motor and the battery system to reduce charging energy in the battery system.
2. The method according to claim 1, wherein said converting the energy of the target direct current and the target quadrature current based on the motor controller and distributing the converted energy to a motor and a battery system, comprises: Transmitting the target direct-axis current and the target quadrature-axis current to a current loop in the motor controller to calculate direct-axis voltage and quadrature-axis voltage of the permanent magnet synchronous motor; Transmitting the direct-axis voltage and the quadrature-axis voltage to space vector pulse width modulation for energy conversion, distributing the converted energy to a motor, and feeding the converted energy back to the battery system through the current loop after coordinate conversion.
3. The method for realizing the electric retarder according to claim 2, wherein the direct-axis voltage and the quadrature-axis voltage of the permanent magnet synchronous motor are calculated through a voltage equation of the embedded permanent magnet synchronous motor; the voltage equation of the embedded permanent magnet synchronous motor is as follows: ; ; Wherein Rs is the stator resistance of the permanent magnet synchronous motor, ld is the direct axis inductance of the permanent magnet synchronous motor, lq is the quadrature axis inductance of the permanent magnet synchronous motor, id is the target direct axis current of the permanent magnet synchronous motor, iq is the target quadrature axis current of the permanent magnet synchronous motor, ψf is the permanent magnet flux linkage of the permanent magnet synchronous motor, we is the electrical angular velocity of the permanent magnet synchronous motor, ud is the direct axis voltage of the permanent magnet synchronous motor, and Uq is the quadrature axis voltage of the permanent magnet synchronous motor.
4. The method according to claim 1, wherein traversing the target lookup table based on the generated torque to obtain the target direct current and the target quadrature current of the permanent magnet synchronous motor comprises: acquiring a target torque curve of the power generation torque in the target lookup table; And acquiring the target torque curve, the position points where the maximum torque curve intersects with the equal current circle in the lookup table, and acquiring the target direct axis current and the target quadrature axis current of the permanent magnet synchronous motor corresponding to the position points.
5. The method according to claim 1, characterized in that the voltage equation of the permanent magnet synchronous motor in steady state: ; ; Wherein Rs is the stator resistance of the permanent magnet synchronous motor, ld is the direct axis inductance of the permanent magnet synchronous motor, lq is the quadrature axis inductance of the permanent magnet synchronous motor, id is the target direct axis current of the permanent magnet synchronous motor, iq is the target quadrature axis current of the permanent magnet synchronous motor, ψf is the permanent magnet flux linkage of the permanent magnet synchronous motor, we is the electrical angular velocity of the permanent magnet synchronous motor, ud is the direct axis voltage of the permanent magnet synchronous motor, and Uq is the quadrature axis voltage of the permanent magnet synchronous motor.
6. The method for implementing an electric retarder according to claim 1, wherein the torque equation of the in-line permanent magnet synchronous motor is: ; ; Wherein Te is electromagnetic torque, np is motor pole pair number, ψf is permanent magnet flux linkage of the permanent magnet synchronous motor, iq is quadrature axis current of the permanent magnet synchronous motor, id is direct axis current of the permanent magnet synchronous motor, ld is direct axis inductance of the permanent magnet synchronous motor, and Lq is quadrature axis inductance of the permanent magnet synchronous motor.
7. An implementation system of an electric retarder, comprising: The power generation torque transmission unit is used for requesting braking power generation torque to be transmitted to the motor controller through the whole-vehicle-domain controller when the brake pedal is triggered; the curve construction unit is used for constructing a maximum torque curve and an equal torque curve based on a torque equation of the embedded permanent magnet synchronous motor; the constant current circle construction unit is used for constructing a constant current circle based on a voltage equation of the permanent magnet synchronous motor in a steady state; A target lookup table construction unit, configured to construct a target lookup table of a torque-current correspondence relationship based on the maximum torque curve, the equal torque curve, and the equal current circle; A target current acquisition unit for traversing the target lookup table based on the generated torque to acquire a target direct axis current and a target quadrature axis current of the permanent magnet synchronous motor; An energy conversion unit for performing energy conversion on the target direct-axis current and the target quadrature-axis current based on the motor controller, and distributing the converted energy to a motor and a battery system; the current redistribution unit is used for obtaining a new target direct-axis current and a new target quadrature-axis current of the permanent magnet synchronous motor based on the target lookup table when the voltage in the battery exceeds a preset value, and distributing the new target direct-axis current and the new target quadrature-axis current so as to reduce the charging energy in the battery system; The current redistribution unit includes: a brake request unit for requesting braking of the generated torque to be transmitted to the motor controller through the whole-vehicle-domain controller when the voltage in the battery exceeds a preset value; A target position point obtaining unit, configured to traverse the target lookup table through the motor controller, so as to obtain a target position point where an equal torque curve corresponding to the generated torque only intersects with the equal current circle, and obtain the new target straight axis current and the new target quadrature axis current corresponding to the target position point; And a voltage reduction unit for converting energy based on the new target direct-axis current and the new target quadrature-axis current by the motor controller, and distributing the converted energy to the motor and the battery system to reduce charging energy in the battery system.
8. The system for implementing an electric retarder according to claim 7, wherein the energy conversion unit comprises: The voltage calculation unit is used for transmitting the target direct-axis current and the target quadrature-axis current to a current loop in the motor controller so as to calculate the direct-axis voltage and the quadrature-axis voltage of the permanent magnet synchronous motor; and the energy distribution unit is used for transmitting the direct-axis voltage and the quadrature-axis voltage to space vector pulse width modulation for energy conversion, distributing the converted energy to a motor, and feeding the converted energy back to the battery system through the current loop after coordinate conversion.

Description

Implementation method and system of electric retarder Technical Field The application relates to the technical field of electric automobile control, in particular to an implementation method and system of an electric retarder. Background At present, the motor on the new energy electric automobile finishes the mutual conversion of electric energy and mechanical energy. The electric retarder is a retarder device which utilizes a motor connected with a driving wheel to generate retarding action on a running vehicle. This is accomplished by changing the motor to a generator. The driver generates corresponding electric torque or generated torque through an accelerator pedal and a brake pedal and outputs the generated torque to the motor controller, and the motor controller converts the required torque into corresponding current, thereby generating driving force or braking force. However, when the conventional point-to-retarder meets special road conditions such as long downhill and the like, and meanwhile, when the battery voltage is very high, the braking force cannot be converted into heat in time to be consumed, so that the energy recovery and the abrasion of mechanical braking are increased. Disclosure of Invention The embodiment of the application aims to provide an implementation method and system of an electric retarder, which can timely convert braking force into heat to be consumed, reduce energy recovery and reduce abrasion of mechanical brake. In order to solve the above technical problems, an embodiment of the present application provides a method for implementing an electric retarder, including: when the brake pedal is triggered, requesting braking power generation torque to be transmitted to the motor controller through the whole-vehicle-domain controller; Traversing a target lookup table based on the generated torque to obtain target direct axis current and target quadrature axis current of the permanent magnet synchronous motor; performing energy conversion on the target direct-axis current and the target quadrature-axis current based on the motor controller, and distributing the converted energy to a motor and a battery system; And when the voltage in the battery exceeds a preset value, acquiring a new target direct-axis current and a new target quadrature-axis current of the permanent magnet synchronous motor based on the target lookup table, and distributing the new target direct-axis current and the new target quadrature-axis current to reduce the charging energy in the battery system. Further, the energy conversion based on the target direct-axis current and the target quadrature-axis current based on the motor controller, and distributing the converted energy to a motor and a battery system, comprising: Transmitting the target direct-axis current and the target quadrature-axis current to a current loop in the motor controller to calculate direct-axis voltage and quadrature-axis voltage of the permanent magnet synchronous motor; Transmitting the direct-axis voltage and the quadrature-axis voltage to space vector pulse width modulation for energy conversion, distributing the converted energy to a motor, and feeding the converted energy back to the battery system through the current loop after coordinate conversion. Further, calculating the direct axis voltage and the quadrature axis voltage of the permanent magnet synchronous motor through a voltage equation of the embedded permanent magnet synchronous motor; the voltage equation of the embedded permanent magnet synchronous motor is as follows: Wherein Rs is the stator resistance of the permanent magnet synchronous motor, ld is the direct axis inductance of the permanent magnet synchronous motor, lq is the quadrature axis inductance of the permanent magnet synchronous motor, id is the target direct axis current of the permanent magnet synchronous motor, iq is the target quadrature axis current of the permanent magnet synchronous motor, ψf is the permanent magnet flux linkage of the permanent magnet synchronous motor, we is the electrical angular velocity of the permanent magnet synchronous motor, ud is the direct axis voltage of the permanent magnet synchronous motor, and Uq is the quadrature axis voltage of the permanent magnet synchronous motor. Further, before traversing the target lookup table based on the generated torque to obtain the target direct axis current and the target quadrature axis current of the permanent magnet synchronous motor, the method includes: Constructing a maximum torque curve and an equal torque curve based on a torque equation of the embedded permanent magnet synchronous motor; Constructing an equal current circle based on a voltage equation of the permanent magnet synchronous motor in a steady state; and constructing the target lookup table of the corresponding relation between the torque and the current based on the maximum torque curve, the equal torque curve and the equal current circle. Further, traversing th