A Novel Adaptive Control of PMSM for Electric Vehicle

Permanent magnet synchronous motor (PMSM) has become preferred motor for electric vehicles owing to its small volume, high efficiency and power density. However, there are still 2 problems of adaption control of PMSM. First, there are four parameters in cascade proportion-integration(PI) controllers of speed and current loops of PMSM to be adjusted, making traditional parameters setting and advanced parameters self-adjustment rather complicated and having high computation cost. In addition, there is no evident physical meaning in controller parameters of speed and current loops. Second, precise parameters of the motor are needed in order to guarantee performance of the PMSM control system. In this paper, the form of traditional PI controller is transformed. In the new form, proportional and integral coefficients of the PI controllers for PMSM speed and current loops are set by motor parameters and two control parameters, damping coefficient and band width respectively, making it convenient to tune both of the controllers for PMSM. Furthermore, PMSM parameters including stator inductance, stator resistance and rotor flux are identified using recursive least square(RLS) method with forgetting factor. The new PI controllers together with parameter identification adaptively control current and speed of the motor. Simulation are carried out to verify the control performance.