A Sensorless Initial Rotor Position Estimation Scheme for a Vector Controlled IPMSM Drive

Vector field oriented control (VFOC) of permanent magnet synchronous motor (PMSM) drive requires accurate velocity information sensed by a speed or position sensor attached to the rotor. Nowadays, sensorless control is adopted in many industrial applications for reasons of robustness, cost, cabling and reliability. This paper presents a novel sensorless control strategy and initial rotor position estimation for a salient-pole permanent-magnet synchronous motor (IPMSM). Model reference adaptive system (MRAS) technique has been used for speed estimation in sensorless speed control of IPMSM with space vector pulse width modulation (SVPWM). The MRAS technique is simple and it requires less computation time. The stability of the proposed speed estimation technique is achieved through Popov’s hyperstability criteria. The initial rotor position is estimated by a suitable sequence of voltage pulses intermittently applied to the stator windings at standstill and the measurement of the peak current values. To illustrate our work, we present experimental results for an IPMSM obtained on a floating point digital signal processor (DSP) TMS320F240 based control system. Experimental results show that the MRAS technique speed estimation provides high performance sensorless control of IPMSM drive.