Sensorless control of four-switch three-phase PMSM drive using extended kalman filter

This paper investigates performances of an extended kalman filter (EKF)-based cost-effective drive system of a permanent-magnet synchronous motor (PMSM) for low-cost applications. In this paper, the EKF is used as a speed and position estimator and the motor is fed from a four-switch three-phase (FSTP) inverter instead of a conventional six-switch three-phase (SSTP) inverter. This configuration reduces the cost of the inverter, the switching losses, and the complexity of the control algorithms. The robustness of the proposed EKF-based FSTP inverter fed PMSM drive is verified by simulation results at different operating conditions. A comparison of the proposed FSTP inverter fed PMSM drive with a conventional SSTP inverter system is also made in terms of performance and error analysis. The proposed FSTP inverter fed PMSM drive is found quite acceptable considering its performance, cost reduction and other advantages.