Parameterized and centralized secondary voltage control for autonomous microgrids

Abstract The paper presents a novel secondary voltage control scheme for autonomous microgrids. The proposed scheme is accomplished by a secondary voltage controller combined with a parameter decision modular. The secondary controller generates new voltage reference signals for Q-U droop control upon the operation statuses, and the parameter decision modular generates the regulation parameters for secondary voltage controller. Reactive power allocation coefficient is used to regulate output ratio of reactive power of DG units while reactive power weight is used to realize the rough-tuning for bus voltage and voltage weight for fine-tuning. Numerical simulation results show that the reactive power is shared accurately among DG units at the desired ratio and the voltage of any bus is restored with sufficient spare capacity by the proposed secondary scheme.