Position control Of BLDC motor with modified bipolar PWM for clutch system Of PHEV

Generally, PHEV(plug-in hybrid electric vehicle) is driven by the engine, the primary traction motor, and the secondary auxiliary motor generating the electric power for battery charging. Secondary auxiliary motor should be connected to the engine or separated from the engine by the clutch system. This paper presents the position controller using BLDC motor for the clutch system of PHEV. BLDC motor can be applied to the clutch system in spite of it´s low resolution of the position sensor due to high gear ratio between the clutch and the motor. Since the attachment and the detachment between the motor and the engine should be carried out within 0.3 seconds, the position controller with fast acceleration and deceleration must be implemented. For the torque control with braking operation for the BLDC motor, the modified bipolar PWM method with low current ripple compared to the conventional unipolar PWM is proposed. The position control performance of the BLDC motor for clutch system is verified through the simulation and experiments.