Simple compensation strategy and unified control scheme for universal power quality controller

This paper proposes the concept of combining the functions of harmonic compensation of a double-converter compensator with the compensation of short-term voltage disturbances. The equipment based on this concept is called Universal Power Quality Controller. It is intended to compensate major power quality problems (harmonics and voltage sags) originated both from the load side and from the supply source side and does not require more power rating of converters than the original harmonic compensation. A compensation strategy and a unified control scheme for this universal power quality controller are proposed, which are very simple compared to those for other multiple-function compensators and the respective control algorithms for the two converters are also proposed and discussed in detail. Simulation and prototype experimental results are presented to validate these control methods and corresponding performance of the universal power quality controller.