Flux-Weakening Control of Switched Reluctance Machines in Rotating Reference Frame

A flux-weakening control for switched reluctance motors (SRMs) in the rotating reference frame is proposed in this paper. This rotating reference frame control of SRM mimics the control of synchronous machines (SMs). The method uses the periodic nature of the quasi-sinusoidal static torque characteristics to establish the rotating reference frame. A novel negativity removal block and a simplified nonlinearity handling block are introduced to ensure a smooth torque sharing among different phases and adjust for the SRMs unique operating principle. In the $dq$ control method, a $d$-axis current is commanded for weakening the flux. An adaptive control method that uses the commanded and actual currents determines the required amount of flux weakening. Through the unique features of $dq$ controls, the proposed method offers smooth torque at low speed and supports a wide-speed operation. The proposed control method is verified experimentally.