A Nonlinear Observer for High-Performance Sensorless Speed Control of IPMSM Drive

This paper aims to provide a high-performance sensorless control of interior permanent magnet synchronous motor (IPMSM) based on nonlinear position and speed observer. The proposed nonlinear observer is constructed using the flux linkage as new state variable without speed dependence. The nonlinear observer gives estimation of the rotor position using a trigonometric function and the speed estimation is obtained from estimated position using proportional-integral (PI) tracking controller. This observer is stable easy to implement and does not require a large computing time. At standstill, we used the voltage pulses method to detect the initial rotor position. Short voltage pulses are applied to the stator winding and the initial rotor position is estimated from the measured peak current. High-dynamic performance is obtained using the vector field-oriented control and the space vector pulsewidth modulation techniques. Experimental results with 1.1-kW IPMSM have validated the effectiveness of the proposed sensorless speed control using nonlinear observer. The experimental implementation is carried out on powerful dSpace DS1103 controller board based on the DSP TMS320F240.