New direct torque and flux control with improved torque per ampere for switched reluctance motor

Abstract

Inherent torque ripple, acoustic noise and vibration are the major hindrances of switched reluctance motor (SRM)for wide acceptance in the automotive industry. To avoid stability issues in electrified vehicles, smooth torque control of an SRM is requisite. Torque ripple in the SRM can be avoided by proper machine design and/or directly controlling the torque. To maintain the torque within the hysteresis band in the conventional direct torque and flux control (DTFC), a high value of RMS current flows through the motor windings. This results in an increase in copper losses and reduces the net torque per ampere ratio. This paper addresses this issue by proposing a new DTFC technique for an SRM drive with the features of improved torque per ampere while maintaining the torque within the hysteresis bands. MATLAB simulations show that the proposed DTFC technique enhances torque per ampere ratio while minimizing the torque ripple. The effectiveness of the proposed DTFC strategy is also demonstrated through real-time simulations in the OPAL-RT digital platform. Real-time results show that the proposed DTFC strategy exhibits better performance in comparison to the conventional DTFC under steady-state and dynamic conditions. � 2019 IEEE.