Switching strategies for active power filters

This thesis is concerned with the development of simple and effective switching strategies for active power filtering appUcations. A switching strategy for active power filters which has been presented recently is based on an Equal-Sampling Technique (EST). This approach involves the solution of a set of non-linear equations. The main difficulty with the EST is its high computational burden and slow response when load current changes take place. A Modified Equal Sampling Technique (MEST) and a Centroid Based Technique (CBT) are proposed in this thesis. The proposed strategies are computationally simpler to implement and in both cases provide equal or improved performance when compared to the EST. The common feature of the two new schemes is that the injected current pulsewidths are determined based on an equal area criteria. In addition, in case of CBT, the centroid of both the injected current pulses and corresponding harmonic current are constrained to occupy the same position in the time domain.