Power enhancement of dual inverter for open-end permanent magnet synchronous motor

This paper proposes control methods of dual inverter driven open-end permanent magnet synchronous motor (PMSM) which can generate maximum output power in overall speed range. Due to the high back-EMF of PMSM in high speed region, PMSM needs high DC link voltage and field weakening control. In the dual inverter driven open-end PMSM system which one inverter is connected to the only power source and other one is flied without source, active and reactive voltage have to be decoupled to make flied DC link voltage stable. This paper proposes power enhancement method for suggested system by maximizing active power to the motor with six-step operation of source connected inverter. At the same time, ripple voltage from six-step operation which causes torque ripple is compensated by opposite inverter. Analyses, strategies, control method, simulations, and experimental results are descripted in the paper.