Research on the Control of a Radial-Radial Flux Compound-Structure Permanent-Magnet Synchronous Machine Used for HEVs

A compound-structure permanent-magnet synchronous machine (CS-PMSM) system is a power train concept used in hybrid electric vehicles (HEVs). It can help an internal combustion engine (ICE) to realize a full control of torque and speed independent of road conditions, thus increasing efficiency, decreasing emissions and fuel consumption. The key part CS-PMSM is an integration of two permanent-magnet synchronous machines. Due to its special configuration, the transient model and control strategy are different from those of conventional machines. The feasible control of a radial-radial- flux CS-PMSM is investigated in this paper. The transient model is established and the integrated control block diagram is configured. The feasibility of control strategy for this particular structure is validated by the simulations of the CS-PMSM four different operating modes. Moreover, the influence of machine parameters on the required current provided by inverter is discussed, and the optimum choice of conductors per slot is obtained to minimize the inverter rating.