Starting Method Of PMSM For Range Extender System Based On Hall Position Sensors

Range-extender System is mainly composed of internal combustion engine and generator, can effectively improve the electric vehicle driving range, reduce the battery depth of discharge and prolong battery life. Permanent magnet synchronous motor(PMSM)is applied to Range-extender System due to the high power density,high torque and high generation efficiency combined with the power converter. PMSM closed-loop control involves the PI parameters tunning from startor to generator. Hall position sensors instead of the high-precision position sensors can effectively reduce the cost of Range-extender System, the detection method is simple and reliable, but motor control is more difficult due to the limitation of low resolution.Firstly, the Six-step current vector control starting method with PMSM of Range-extender System is analysed. And the effects of different rotor position deviation to electromagnetic torque with Six-step current vector control is analysed. The average electromagnetic torque and the start time is compared respectively with accurate rotor position vector control, rotor position deviation 0°and 30° of Six-step current vector control through theoretical analysis. Then, rotor position deviation 30° of Six-step current vector control starting method is confirmed due to higher average torque, lower cost and start time similar to accurate rotor position vector control.Secondly, the S-domain model of inner current control loop composed of PI controler, power converter and PMSM is analyzed in consideration that the inner current control loop is same during PMSM starting and generating. And the pole-zero cancellation method offline is used based on Nyquist stability criterion. The closed loop theoretical PI parameters are determined. The closed-loop PI parameters applied to PMSM of Range-extender system starting mode and generating mode are confirmed by experience based on theoretical values,in consideration that the stability of the closed loop control system in generating mode and fast tracking current signal.Finally, the average electromagnetic torque and the start time are compared respectively with accurate rotor position vector control, rotor position deviation 0°and 30° of Six-step current vector control through Simulink simulation, constant load starting experiments and general internal combustion engine load starting experiments. And then, the applicability of the closed-loop PI parameters of PMSM wide speed range among starting mode and generating mode is verified through PMSM starting and generating state transitions experiments.