Analysis of current-regulated voltage-source inverters for permanent magnet synchronous motor drives in normal and extended speed ranges

For a high-performance PMSM (permanent magnet synchronous motor) drive, appropriate choice of the power converter and of the controller is achieved using computer simulation of the drive system. The generation of a smooth torque at low speeds and the system operating limits in the high and extended-speed ranges are investigated. A numerical simulation of the drive is used to study various control strategies. Simulation results for ramp, hysteresis, and space-vector-type current controllers are presented to illustrate important performance characteristics of each. The nature of current regulator saturation is described and a flux weakening algorithm is discussed in order to achieve extended torque-speed characteristics above the rated speed