Sigma-Delta modulation applied to a 3-phase shunt active power filter using compensation with instantaneous power theory

Shunt active power filter play an important role in reducing harmonic currents and reactive power in power lines, so necessarily it has to be effective and reliable as much as possible. In this paper the power section of power active filter is viewed as analog to digital converter (ADC), then as a result a three-phase shunt active filter with modulator controller which uses Sigma-Delta analog to digital converter is presented aimed at improving modulator performance. Proposed active filter performance simulated using PSCAD/EMTDC^® package with rectifier as load which is main non-linear load of power systems. Afterwards simulation results compared with hysteresis band current controlled system which is popularly used among the various conventional techniques.