A flux-weakening control approach for interior permanent magnet synchronous motors based on Z-source inverters

This paper presents a flux-weakening solution by employing the voltage boost capability of Z-source inverters to overcome the voltage limitation in conventional drives for high-speed applications, e.g. hybrid/electric vehicles. In this control strategy, a flux-weakening algorithm has been developed to achieve constant output power of an interior permanent magnet synchronous motor (IPMSM). Correspondingly, a flux-weakening control strategy including a closed-loop speed control is presented. Compared to existing flux-weakening methods, this attractive control strategy allows an IPMSM to largely extend its constant power speed range and operate at higher speed with larger torque. Theoretical analysis is given in detail, and corresponding simulation results are presented to verify the presented control technique.