Decoupled Power Controller for Inverter-interfaced Distributed Generation System

This paper introduces concept of decoupled power controller for tracking load demand of an inverter-interfaced distributed generation (DG) system. The approach suggested in the paper uses reference frame theory to decouple quadrature axis and direct axis currents. As compared to the power-frequency droop based controller, the proposed controller design involves exact mathematical formulation in terms of quadrature and direct axis powers. It also relinquishes forced relationship between the DG variables like power and frequency. The controller has been simulated using MATLAB/SIMULINK for single DG feeding a three phase balanced load. Step changes in quadrature axis and direct axis load are simulated to illustrate the performance of the controller. Results showing response of the DG controller to the load change are presented and discussed in the paper.