A new control strategy of power sharing in islanded microgrids

Abstract

This paper proposes a new control sharing technique for parallel three-phase inverters in an islanded microgrid. The new control technique combining the adaptive impedance controller and the communication among the parallel inverters to accurately share real power and reactive power when there is a distinct difference between line impedances and the loads change in the microgrid. In this technique, the communication information is used to update the virtual impedance to compensate the voltage drop. If the interruption occurs, the stand-alone control mode is independently applied to quickly re-establish the balanced state. Therefore, the accuracy of the power sharing in this technique is within the allowed system limits. The communication network between the inverters and the control center is shown in Fig. 2 and the real and reactive power sharing controller is shown in Fig. 3. The simulation results have indicated that the proposed technique is better than the traditional droop control in terms of the accuracy and stability. Therefore, the new proposed technique can be a favorably alternative model for real power and reactive power sharing control of parallel inverters in a islanded microgrid.