A control algorithm for the stable operation of interfaced converters in microgrid systems

This paper deals with a control concept for enhancing the stable operation of microgrid plan during the grid connected and islanding modes. The Lyapunov control theory is considered in this paper to analyze the dynamic behavior of distributed generation (DG) units during the power sharing with utility grid and loads. The compensation of instantaneous variations in the reference current components of DG units in ac-side and dc-voltage variations in dc-side of the interfaced converters are considered properly in this control scheme, which is the main contribution of this work in comparison with the other potential control strategies. By utilization of the proposed control scheme, DG units can provide the continuous injection of active power from the dispersed energy sources to the local loads and/or main grid during the islanding and grid-connected modes. Furthermore, reactive power and harmonic current components of loads can be provided with a fast dynamic response in a stable operational region. Simulation results confirm the effectiveness of the proposed control strategy in the proposed microgrid plan during the dynamic and steady-state operating conditions.