Voltage Unbalance and Harmonic Compensation in Microgrids by Cooperation of Distributed Generators and Active Power Filters

摘要

In this paper, the power quality of microgrids is addressed. To achieve the desired level of power quality, a strategy based on the coordinated control between DGs andAPFs is proposed. In this regard, hierarchical control is applied where primary control consists of power droop controller of DGs, selective virtual impedance and voltage/current regulators. Based on the secondary control, at first voltage harmonic compensation and voltage unbalance compensation of point of common coupling (PCC), that might includes sensitive loads, is carried out by DGs. Voltage compensation of PCC by DGs may cause severe voltage distortion at DGs terminals. Thus, the coordinated control is used to mitigate the voltage distortion to the defined maximum allowable value at DGs terminals. Evaluation of the proposed hierarchical control is carried out by a simulation study.