Research on Economic Operation Strategy of AC / DC Hybrid Distribution Network Based on Power Electronic Transformer

Multi-port Power Electronic Transformer (PET) can establish a flexible power circulation path in the AC/DC hybrid power distribution network to achieve inter-regional energy interconnection and mutual support. This paper proposes an economic operation strategy of AC/DC hybrid distribution network based on multi-port PET. Firstly, based on the typical topology of the AC/DC hybrid distribution network, the flexible regulation capability of the AC/DC distribution network including PET is analyzed. Then, according to the physical constraints during the operation of PET, the power flow relationship of each port of multi-port PET is analyzed, and the energy flow model of PET in the hybrid distribution network is established. Finally, taking the lowest operation cost of the AC/DC hybrid distribution network as the objective function, and taking the system power balance, power flow limit violation and equipment operation as constraints, the day-ahead economic operation model of the AC/DC hybrid distribution network is established and a model solving method based on CPLEX solver is proposed. Taking an AC/DC hybrid distribution network demonstration project in a certain area as an example, the day-ahead economic operation model of the demonstration project is established and solved. The calculation results show that the proposed PET-based AC / DC hybrid distribution network economic operation strategy can effectively reduce the system operation cost and increase the level of renewable energy accommodation.