One cycle controlled active harmonic filter

Abstract

Load compensators have become popular because of the enhanced concern over deteriorating power quality figures caused due to the proliferation of power electronic based systems which pose themselves as non-linear type of loads to the utility. Modern load compensators have better filtering performance, small physical size, and more flexibility in application, but are still not very competitive in terms of its cost and increased losses compared to traditional passive filters, especially if it is used for compensating reactive power requirement of the load. Innovative and advanced controllers like one cycle control (OCC) having fast transient response and which do not require the service of a phase locked loop (PLL) have been used for active load compensation. But existing OCC based load compensators do not have the capability to distinguish between fundamental reactive component of the load current and its higher order harmonic components and end up compensating for both. This leads to an increase in the rating of the converter. The proposed OCC based shunt harmonic filter compensates only for the harmonic component of the load current, while retaining the advantages of the original OCC based schemes.