Fault-tolerant inverter permanent magnet synchronous motor position sensorless control system

In order to improve reliability, a new fault-tolerant inverter based permanent magnet synchronous motor (PMSM) position sensorless control system is proposed to avoid fragile parts of power components and position sensor. The fault-tolerant inverter topology was adopted and its four switches were used to maintain running when an open-switch fault happened. Sensorless control of PMSM was implemented by means of an adaptive sliding mode observer (SMO). Space vector pulse width modulation of four-switch inverter was studied in order to reduce harmonic. Operating conditions of the system both before and after faults were analyzed and compared by simulations and experiments. The simulation results as well as experimental ones illustrate that the proposed structure and method can realize reliably operation of the system after open-circuit faults in switches.