A multifunction power quality utility for connecting cogeneration systems to the power mains

This paper proposes a multifunctional power quality utility for linking cogeneration systems to the power mains via an standard shunt active power filter together with a DC/DC converter that connects the cogenerator to the DC-link. The main function of this utility is to regulate the active power delivered from the cogeneration system. Besides this function, the utility can also compensate the harmonics generated by nonlinear loads, supply reactive power to the mains, and regulate the voltage at the point of common coupling (PCC). These compensation schemes use a different control strategy, which do not require the load current measurement for harmonic detection. This reduces the number of current sensors employed and their cost of implementation. These power quality objectives can be obtained even though the power mains is unbalanced. The feasibility of the proposed control system is validated by experimental results.