Adaptive control of three level active power filter

Abstract

This paper presents diode clamped multilevel inverter as active power filter for elimination of harmonics current present in the nonlinear load. The power circuit of active power filter is comprised of three level DCMLI with DC bus capacitors. The active filter absorbs harmonics current of load and to inject reactive current requirement of the nonlinear load. Two different control schemes are tailored to estimate the tracking currents of the active power filters. The conventional least mean square (LMS) and adjustable step-size least mean square algorithms are presented for tracking current estimation. The modulation technique based level shift scheme with current regulator is used to track the firing signals for active power filter. The Matlab computer simulation study of active filter with nonlinear load is carried out. The adjustable step size algorithm exhibits improved performance characteristics for an active power filter.