An effective modelling and control strategy for linear switched reluctance motors

Trajectory control is an essential element in advanced manufacturing processes. For demanding direct-drive applications, a linear switched reluctance motor (LSRM) has become a potential candidate because of its low cost and simple structure. However, the inherent non-linearities of the LSRM cause difficulties in its controller design. Recently, a few complicated control approaches and schemes have been proposed to overcome the non-linear characteristics, but they need precise modelling, and their algorithms are hard to realize. This article describes a simple and effective design of the feedback control for the trajectory control of the LSRM driving system, and some of its practical aspects. In the proposed control algorithm, the whole driving system is decomposed into two subsystems with different time scales by using the two-time-scale analysis. On the basis of this method, the position controller and current controllers are designed for the two subsystems, respectively. In this way, the controller structure is simplified and the whole tracking system can be designed tractable. Furthermore, a modified proportional-differential controller is proposed for tracking the sinusoid wave. This article includes modelling analysis, simulation results, and detailed experimental implementation as well.