A robust two-dimensional deadbeat current control method by using adaptive line enhancer for active power filter

The effective system control method to apply three-phase current-source PWM converter with a finite time settling controller to active power filters (APF) is presented. In a shunt-type configuration, the APF is controlled such that the current drawn by the APF from utility is equal to the current harmonics and reactive current required for the load. To attain the tine-optimal response of the APF supply current, two-dimensional deadbeat control scheme is applied to the APF current control. Father more, in order to cancel both the delay in two-dimensional deadbeat control scheme basically and the one delay in DSP control strategy, an adaptive line enhancer (ALE) is to be introduced for the purpose of predicting the desired value of three sampling periods ahead. And ALE has another function of giving the robustness to the deadbeat control system. Due to ALE in a transient state settling time is made short On the other hand, in a steady state total harmonic distortion ratio (T) of source currents can be reduced as much as compared to the case that ideal identification of controlled system could be made. The experimental results obtained from a DSP-based APF are also reported. The compensating ability of this APF is very high m accuracy and responsiveness.