Direct torque control system of electric vehicle based on SVPWM

LI Jie1, HAN Jun-feng2, PAN Sheng-hui1

(1.College of Electrical and Information Engineering, Guangxi University of Science and Technology,

Liuzhou 545006, China; 2. Guangxi Technological College of Machinery and Electricity, Nanning 530007, China)

Abstract: Aiming at the problems of torque pulsation and inconstant inverter switching frequency in the traditional direct torque control system, the mathematical model and the direct torque control method of permanent magnet synchronous motor were studied.A direct torque control system scheme based on space vector pulse width modulation (SVPWM) was presented to adopting the expected voltage vector calculation unit to replace the hysteresis comparator of conventional direct torque system, so that the expected voltage vector can reduce the current of stator flux and torque ripple would be obtained.In order to realize the motor control,the expected voltage vector was converted to the actual voltage vector by using the SVPWM technology.The simulation model of the direct torque control system based on the space vector modulation was built in the Matlab/Simulink. The simulation results indicate that the system can obtain small flux and torque pulsation.

Key words: direct torque control; space vector pulse width modulation(SVPWM); permanent magnet synchronous motor; Matlab/Simulink