Torque control method for motor of pure electric vehicle

Abstract

The invention discloses a torque control method for a motor of an electric vehicle. The torque control method comprises the following steps: firstly, a temperature sensor is built in the stator winding of the driving motor of the pure electric vehicle, and the temperature of the stator winding is measured by adopting the three-wire balanced bridge temperature measurement method; and secondly, the temperature of the stator winding of the driving motor is acquired through an A / D (Analog / Digital) conversion module of a motor controller, the temperature of a rotor is worked out through a stator thermometer according to heat conduction, the size of the flux linkage in different temperatures is worked out according to the demagnetization curve of the rotor material, and then the direct axis current of the motor is adjusted to compensate flux linkage change of the rotor due to temperature variation. The invention has the advantages that firstly, as the temperature sensor is built in the stator winding of the motor, and the three-wire measurement method is adopted, the wiring is simple, resistance errors of lead wires are eliminated; secondly, on-line control of saturation of direct and quadrature axis flux linkages and the flux linkage of a permanent magnet is realized to achieve the purpose of accurately control the motor output torque; and the efficiency of the motor is improved, and the service life of the motor is prolonged.

Description

technical field [0001] The invention relates to a pure electric vehicle permanent magnet synchronous drive motor, in particular to a pure electric vehicle motor torque control method. Background technique [0002] At present, the permanent magnet synchronous drive motor controller used in pure electric vehicles does not have the function of detecting the temperature of the motor rotor, and the change of the temperature of the motor rotor will cause the change of the flux linkage, and the change of the flux linkage caused by the temperature will cause the output torque of the motor to decrease Offset, resulting in lower control accuracy of motor output torque. Contents of the invention [0003] The purpose of the present invention is to provide a pure electric vehicle motor torque control method, which can effectively improve the torque control accuracy of the motor controller by compensating the change of flux linkage caused by temperature. [0004] To achieve the above o...

AI Technical Summary

Problems solved by technology

[0002] At present, the permanent magnet synchronous drive motor controller used in pure electric vehicles does not have the function of detecting the temperature of the motor rotor, and the change of the temperature of the motor rotor will cause the change of the flux linkage, and the change of the flux linkage caused by the temperature will cause the output torque of the motor to decrease Offset, resulting in lower control accuracy of motor output torque