Initial rotor position detecting algorithm of PM synchronous motor using incremental encoder

This paper proposes the initial rotor position detecting algorithm of a PM synchronous motor using an incremental encoder. The proposed algorithm estimates the phase offset between the rotor magnet flux and the z-pulse of the incremental encoder by applying six aligning modes. The absolute rotor position for driving PM synchronous motor is calculated by using the phase offset of the z pulse and A, B pulse signals of the encoder. The PMSM drives based on the estimated rotor position is applied to the elevator door system. The experimental results show that the real speed tracks the reference speed for opening and closing the elevator door.