Priority based current control design in high speed sensorless PMSM drives

The design of current controller in high speed sensorless permanent magnet synchronous machine (PMSM) drives is studied. Due to a computation and a digital pulse-width modulation (DPWM) delays, the maximum achievable speed and current controller bandwidth is limited in high speed application. In order to reduce the delays, a modification in control sequence is proposed, which can significantly reduce the effect of the delay caused by the digital controller. The control priority concept is adapted to reduce the execution time of the PWM generation algorithm. Experimental results demonstrate the high speed operation where 700 Hz fundamental frequency is achieved with 2 kHz switching frequency.