A multifunctional power quality controller for microgrid

Microgrid power quality has some unique features (harmonic high penetration, frequent voltage fluctuation, overcurrent phenomenon and bidirectional power flow) compared to the conventional power grid, as a result of the intermittence and random of the distributed energy resources. Also it is not cost effective to install various types of power quality controller because of small capacity of the microgrid. In order to cater for the peculiar requirements of microgrid power quality, a novel multifunctional power quality controller (MPQC) suitable for microgrid is proposed and the operational principle is described. The MPQC plays the role of voltage compensation, fault current limiter, power flow control and harmonic isolation. The control scheme is also given. A PSIM simulation model and a prototype of MPQC has been constructed. The simulation and experimental results verify the validity of the MPQC.