Differential Flatness-Based Control of Switched Reluctance Motors

This paper presents a Differential Flatness-Based Control (FBC) approach for the current control of Switched Reluctance Machines (SRMs), a potential candidate for the automotive industry. The main challenges in SRM control methods stem from motor nonlinearity. In electrical drives, FBC has been applied in doubly-fed induction generators, permanent magnet motors, and magnet-assisted synchronous reluctance motors. Among the few papers that have used FBC for SRM, this research distinguishes itself by addressing current control and considering both current and flux-linkage separately as a flat output, an approach not found in previous literature. The performance of the proposed controls is assessed in a three-phase 12/8 SRM against the conventional hysteresis current controller (HCC) and PI controller. Additionally, it is integrated into a torque-sharing function based on a maximum torque per ampere control strategy. This work uses the Integral Time Absolute Error (ITAE) criterion to compare different control methods. The current ITAE of FBC has been reduced by 50% compared to HCC and 41% compared to the PI controller. This controller is well-suited for transportation applications, mainly traction and propulsion in vehicles, due to its low loss and torque ripple compared to conventional controllers. Moreover, dynamic response to changes in load and dyno speed evidence the enhanced performance of the proposed technique.