Power Flow Optimization for Island Microgrid Minimal Loss Based on Virtual Impedance

The virtual impedance in droop control for adjusting the reactive power distribution between parallel distributed generators is used to regulate the microgrid power flow in this paper. Both considering reactive sharing and microgrid stability, the value range of virtual impedance is analyzed. Since the operating characteristic of the distributed generators with droop control are different from the traditional generators, the traditional power flow calculation is not suitable for this island microgrid. Then the microgrid power model with distributed generator adopted droop control is established to calculate the power flow. In order to optimize the power flow, the objective function with minimum network loss is established, and the Particle Swarm Optimization is used for the optimal virtual impedance.