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

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