Sensorless control of PMSM based on voltage vector pulse method

A new approach to sensorless speed control and initial rotor position estimation for a surface permanent magnet synchronous motor(SPMSM) drive was presented.At a rotating condition,speed and rotor position estimation of SPMSM drive was obtained through a self-adaptive flux observer(SAO) by only measuring phase voltages and currents.The initial rotor position was performed by using the nonlinear magnetization characteristics of the stator core caused by the rotor magnets.Experimental results show that in both steady and transient state,the system can achieve expected performances.