Generalized steady-state modeling for hybrid AC/DC microgrids

In this paper, a generalized models are presented for different hybrid ac/dc microgrids components in the islanded mode of operation. In this scenario, power sharing schemes are based on local information to manage the system power with the absence of the main substation. Instead, the DG units operate based on droop characteristics, thereby forming a multi-slack distribution system, and accordingly stabilize the system frequency and voltage. The introduced models for the DG units and interlinking converters consider the variation of the ac frequency and dc voltage results from the multi-slack nature and different power sharing strategies between the subgrids. The solution of the nonlinear models, represent the system steady-state behavior, are contrasted with detailed time-domain simulations performed in PSCAD/EMTDC environment to evaluate the modeling accuracy.