A high accuracy current component detection method for fully digital, vector-controlled PWM VSI-fed AC drives

A high-accuracy differential-type current component detection method and test results are described. The method is suited for vector-controlled pulse width-modulated (PWM) VSI-fed adjustable-speed AC drives. Its features include elimination of high-frequency current harmonics and correction of the detection error caused by the lag time of time-sharing processing. Since this method allows current-loop calculations at a slower sampling rate with a conventional microprocessor, it realizes a fully digital speed regulator with a minor current component loop. Simulation results and experimental results are presented.>