Control of a Dual Fed Open End Winding SPMSM with a Floating Capacitor

Surface Permanent Magnet Synchronous Motor (SPMSM) are not the first choice when a motor drive is required to operate over a wide speed range with an extended Constant Power Speed Range (CPSR). Nevertheless, SPMSMs offer high torque density, high efficiency simple manufacturing process and robustness which makes them an attractive alternative to Interior PMSMs. The Open End Winding (OEW) dual inverter topology, with one of the two Voltage Source Inverters (VSI) connected to a floating capacitor (FC), has shown to be capable of significantly increasing the operating speed range and CPSR of the SPMSM at the price of an increased controller complexity. In this paper, the analytical state space model of the OEW-FC SPMSM is derived, a state feedback controller is proposed and a possible tuning strategy is given to allow for high dynamics over the whole operating range and simplified controller design and tuning.