A control method for DG connected to the utility grid based on current droop with accurate slope gain

Abstract

Most of the distributed generation (DG) controllers have relied on power control (P and Q droop) to achieve reliable operation of the utility grid. Nevertheless, intrinsically, the power control has slow time response and drifts in frequency and voltage level with load changes. This paper proposes a new current droop control and a new method to accurately determine the slope gain based on graphs theory and tellegen theorem. The distributed generation (DG) control operates by means of active curtailment depending on the voltage level and compensation of the voltage drop. The simulation results have proven that the proposed control is cooperative and stable. Further analysis will be performed with different slope gain in order to enhance optimal operation under load variation (nonlinear and linear).