This paper proposes a sensorless control method of permanent magnet synchronous motor (PMSM) using hybrid pulse width modulation (PWM) with current derivative measurement. The proposed method extracts the position error from the phase voltage and current in only one voltage vector. Then, a second-order phase-locked loop is utilized to obtain the actual rotor position. In addition, the current derivative measurement and hybrid PWM are introduced to apply the sensorless control at low modulation index. To improve the performance, the algorithms of time delay compensation and average current calculation are adopted. The proposed method is verified by 1.5kW PMSM drive system.
