Direct Torque and Flux Control of an IPM Synchronous Motor Drive Using a Backstepping Approach

This paper presents a novel direct torque and flux controlled interior permanent magnet synchronous motor (IPMSM) drive using an adaptive backstepping technique. Closed-loop regulation of the speed, torque and stator flux linkage are achieved by a nonlinear controller. Using Lyapunov analysis, the stability of the controller is guaranteed. The reference voltage vectors are generated by a SVM unit, which replaces the switching table in the conventional DTC scheme. Whilst retaining its main advantages, the proposed backstepping controller features reduced torque and flux ripples as compared to the classical DTC. On the hand, a comparison with the PI direct torque and flux control (DTFC) scheme shows that the proposed approach is superior. Experimental results confirm the effectiveness of the proposed method.