Power Control in an Islanded Microgrid Using Virtual Impedance

The common droop method is one of the most effective methods for controlling power-sharing in islanded microgrid. Due to the dependence of the active and reactive power on the voltage and frequency in resistor microgrid, the use of this method in controlling the power-sharing in these types of a microgrid to the undesirable performance of active and reactive power-sharing. In this paper, by applying virtual impedance in the local controller of distributed generation resources, this paper has modified the common droop method and improved power-sharing. The proposed virtual impedance has an adjustable resistor section and a fixed reactance section. Simulation of a typical islanded microgrid in PSCAD / EMTDC software shows that the proposed method is capable of improving the active and reactive power sharing in resistive microgrid controlled by the droop method.