Evaluation of non-active current compensation in smart grids

This paper presents an analysis of instantaneous ABC power compensation in a micro-grid operated in island mode. The differences of this paper to conventional approaches are the use of a four wires grid architecture, system operation under load, and voltage unbalances. The smart grid utilizes a voltage source inverter operating in island mode with the droop control technique, and an energy storage device with additional task is proposed to inject the current according to a coordination algorithm. The compensation of current uses a flexible ABC theory based on the formulation by Lagrange optimization. Hence the analysis is realized for two compensation objectives, one is invariant instantaneous power and the second uses constant power (non-oscillation of power in the system is desired). An analysis has been done by simulation of the micro-grid using a segment of the CIGRE benchmark. Finally, the results for compensation show a comparison of the classical ABC theory and the flexible ABC method.