STATCOM Based on Cascade H-Bridge Converter for Compensating Reactive Power and Current Harmonics Simultaneously

摘要

This paper presents how, through a suitable DC link regulation strategy, the cascade H-bridge converter can perform reactive power compensation and active filter functions simultaneously. The proposal consists in taking advantage of the fact that a current injected by STATCOM can be split up in three components that are linearly independent. The first component is devoted to compensate the converter losses in order to maintain the DC links regulated, the second component is in charge of compensating the reactive power and the third one is used to compensate current harmonics. As part of the control strategy it is shown how to generate individual control signal for each cell even if the multilevel converter is symmetrical or asymmetrical. A two cell binary prototype is used to evaluate the control scheme performance. Simulation and experimental results are presented.