Stable V/f control system with controlled power factor angle for permanent magnet synchronous motor drives

This study develops a scalar V/f control system for permanent magnet synchronous motor drives with two stabilising feedback corrections: a voltage-vector speed correction using active power variation, operating only in transient states and a voltage amplitude correction based on controlled power-factor regulation loop, employing reactive power. Motor/generator operating mode is allowed using the active-power sign information. Simulation and experimental results, and comparison with a medium complexity sensorless vector control prove good performance for the proposed control structure in steady and transient states, at low and rated speed operation with rated load disturbances.