Analysis and design of a linear control strategy for three-phase UPQCs

A linear control scheme applied to a UPQC which is based on back-to-back connected series and parallel compensators sharing a common DC link is presented. The topology combined with the proposed control strategy allows to compensate for utility disturbances such as flickers, sags and swells. It also provides reactive power and current harmonic compensation. As a result, the load operates under constant supply voltage while the utility at a given power factor. Additionally, taking advantage of the arbitrary load phase, an optimization algorithm permits to operate the topology at minimum power losses thus improving the overall system efficiency. Preliminary simulated results confirm the theoretical considerations.