Sensorless control of switched reluctance motor for three-phase full-bridge inverter drive

A novel sensorless control for switched reluctance motor (SRM) driven by the three-phase full-bridge inverter is proposed. The most commonly used drive for SRM is the asymmetric half-bridge inverter but its main disadvantage is the cost due to the number of switches and diodes required to realized the drive, in comparison with the much cheaper and more widely available three-phase full-bridge inverter modules. The overall cost of SRM drive can be significantly reduced when a standard three-phase full-bridge inverter power module can be effectively integrated with sensorless control technique to further eliminate encoder cost. The proposed sensorless method based on the voltage pulse injection technique has been successfully implemented on a low-cost microcontroller with voltage PWM control for a 1.5 kW, 6/4 SRM with rated speed 1,500 r/min.