Dynamic Current Limitation to Provide Interactive Features of Power-Electronics Interfaced Distributed Generation

By Fainan Hassan and Math Bollen

This paper proposes a simple DC current chopper combined with the reactive power control, in order to provide specific interactive capabilities for power-electronics interfaced distributed generation units. The chopper provides a dynamic current limitation capability. During voltage disturbances, it can reduce the active current command to allow more reactive current to be injected into the grid. The proposed controller has been implemented for the mitigation of voltage magnitude variations at the connection point. It will be shown that the proposed controller results in better regulation of both grid and DC-link voltages. Moreover, through the proper sizing of the chopper, the fault ride-through capability is increased and a robust distinction is made by the DG unit between ride-through and islanding operation.