A Voltage Support Method for Point of Common Coupling Considering the Internal of Active Distribution Network

At present, the increased dependency on renewable energy let to the increasing in the proportion of renewable energy in the distribution network. Controlling the distributed generation to support the voltage of point of common coupling is a widely used strategy to increase the stability of the power system. However, most of the existing methods just focus on the stability of the point of common coupling voltage while neglect the voltage at the points of DGs connected. Therefore, in this paper, a PCC voltage support method that can also maintain the DGs connected point voltage into the rated range is proposed. When the voltage at the DGs connected points are within the rated range, the DGs output reactive power according to the droop curve. When the DGs connected points outrange the rated range, the DGs controller starts to search the reactive power limit that can produce corresponding reactive power to support PCC voltage while maintain the connected points within the rated range. The proposed method is verified in a test distribution system.