关键词: 电动汽车, 增程器, 无刷直流电机, 发电, 直接转矩控制

Abstract: In order to improve the dynamic and static performance of the brushless DC generator system in range extender of electric vehicles, it was proposed that the stability of the output voltage of the system should be quickly maintained by controlling the electromagnetic torque. The theoretical basis of direct torque control ( DTC) for brushless DC ( BLDC) power generation system was derived, and the principle of DTC was studied. It was pointed out that the electromagnetic torque could be changed rapidly by selecting the voltage vector with the largest q-axis component acting on the motor. The characteristics of voltage vector was analyzed, and the selection table of voltage vector in direct torque control for brushless DC generation system was established. The simulation and experimental results show that the brushless DC generation system with direct torque control has excellent dynamic and static performance.

Key words: electric vehicle, range extender, brushless DC motor, power generation, direct torque control( DTC)