Improving the stability of hybrid microgrids by nonlinear centralized control in island performance

Abstract

In this paper, based on the nonlinear controller, a new structure is presented for centralized control of hybrid microgrids. In the proposed model, AC and DC buses are used to connect AC and DC sources and loads respectively. A bidirectional interface converter (BIC) is provided for the electrical and control connection of these two buses. Here, based on the generalized backstepping method (GBM), a new method is presented for integrated and simultaneous controlling of AC bus frequency and DC bus voltage. The advantages of this method are the centralized control of the hybrid microgrid, taking into account the dynamics of the whole system and the interaction of its state variables with each other. Harmonized and optimal exchange of power and precise regulation of control signals in this structure has led to improved stability and thus improved system performance. The comparative results of centralized and decentralized control show the efficiency of the proposed model to reduce fluctuations and improve the stability of the system.