Study of coordinated control strategy for hybrid AC–DC microgrid in islanding mode

Abstract

As a kind of generation and distribution system with autonomous control, AC–DC hybrid microgrid plays a pivotal role in the transformation and development of modern power grids. To address the problems of microgrid system instability that occur in islanding mode, the study proposes a coordinated control strategy for hybrid AC/DC microgrid in islanding mode. First, the bidirectional AC/DC interconnection converter is modelled and parametrically designed; second, the control strategy of the interconnection converter in islanding mode is raised, including both active power control with double-loop control and seamless switching of operation modes with pre-synchronous control, and in the end, the effectiveness of the strategy is examined. The data display that under this strategy, the real and reactive power output gaps between the micro sources in the hybrid microgrid do not exceed 0.01 kW and 0.03 kVAR, respectively, and the current during islanding switching is more stable up to 32 A. This shows that the strategy effectively improves the shortcomings of the traditional regulation method, realizes the accurate distribution of real and reactive power, improves the power sharing between DC and AC subgrids, strengthens the stability and reliability of the hybrid microgrid, and helps to promote the technological progress of the hybrid microgrid and escorts the efficient and green development of the smart grid.