Mechanical Position Sensor-Less Torque Control of SRM With Reduced Current Sensors

This paper focuses on a technique for reducing the cost and enhancing the performance and reliability of a switched reluctance motor (SRM). Specifically, it explores a current sensor reduction method for an SRM that operates using the fundamental switching of a midpoint converter. This configuration necessitates the incorporation of four current sensors for all the four phases. The implementation of the torque sharing function (TSF) based direct instantaneous torque control is utilized to minimize torque ripple and to implement current sensors reduction. The current sensing technique employed in this study utilizes a single neutral current sensor together with two sensors for each pair of phase windings and the TSF commutation angles. To enhance the reliability of the drive position sensorless control, an improved observer-based estimation method is used to estimate the rotor position and the speed. The flux linkage-based position estimation scheme utilizes the reconstructed currents for estimating the rotor position. Presented combined current and position sensor reduction method uses a four-phase, eight/six switched reluctance motor (SRM) to assess the viability through simulation findings.