A new approach to estimated rotor position for PMSM based on sliding mode observer

Most methods to estimate the rotor position of permanent magnetic synchronous motor (PMSM) suffer from the motor parameter, which are difficult to be applied due to the complicated algorithm. This paper presents a new approach to estimate the rotor position of PMSM based on the sliding mode observer (SMO). The SMO makes use of the error between the estimated current and measurement current. Back-EMF is obtained by the low pass filter(LPF) . The rotor angle can be a close-loop system in order to improve accuracy and reduce system noise. The rotor position is obtained by the direct integration of the estimated rotor speed. The error due to the pure integration is eliminated by a novel way. The convergence of the SMO is guaranteed. High performance sensorless drive of the PMSM based on SMO is established and the whole system is simulated by matlab. Simulation and experimental results show excellent performance.