Virtual synchronous generator based control sheme of  power electronic transformer

NI Chenhong, SONG Chunwei

(College of Mechanical and Electrical Engineering, China Jiliang University, Hangzhou 310018, China)

Abstract: Aiming at gridtied control sheme and topology of power electronic transformer (PET), virtual synchronous generator (VSG) based control scheme of PET was proposed in this paper. Firstly, VSG based control sheme and its small signal model of traditional PET topology were analyzed, and highorder and multiobjective characteristics of the proposed VSG control model were investigated. Aiming to simplify VSG model of PET, a novel PET control method based on a single VSG model was researched. The novel small signal model with a double closedloop structure was analysed and its advantages were given compared with the VSG model of the traditional PET. The validations of the VSG based gridtied control sheme was verified by simulation results on a PSCAD/EMTDC model of the novel PET. The results indicate that the VSG based control method simplifies gridtied control sheme of PET, which makes PET more suitable for power grid dispatching.

Key words: virtual synchronous generator; power electronic transformer; gridtied inverter