Modular multilevel converter based bus bar in flexible substation

This paper proposes a new Modular Multilevel Converter (MMC) based bus bar. Compared with the traditional bus bar, it can not only realize power control and reactive power compensation, but also prevent voltage drop and allow DC access, so it is very suitable for future flexible substation application. The structure which is composed of two back to back MMC is given. The power analysis and double closed-loop control method are proposed. Compared with other control methods, it adopts the arm current direct control which can remove the need for a circulating current suppressing controller. Simulation results verify the feasibility and correctness of the MMC based bus bar.