VSS control strategy for the reduction of torque ripple for PMSM

This paper proposes the field programmable gate array (FPGA) implementation of a variable structure system (VSS) predictive sequential switching control strategy, as applied to a permanent magnet synchronous machine (PMSM). In the case of AC motor drives, in contrast to conventional vector control where the inverter is not taken into consideration by the controller, the proposed control integrates the inverter model and considers the states of inverter switches as a control variable. It allows the obtaining of faster torque dynamics rather than vector control algorithms. The main design specifications are a reduced switching frequency and simple hardware implementation. A predictive sliding mode controller has been developed, designed as finite state automata (FSM), and implemented with a FPGA. This new logic FPGA torque and speed controller has been developed, analyzed, and experimentally verified.