Modeling and simulation of unified power flow controller based on modular multilevel converters

As the development and building of 220kV and 500kV Unified Power Flow Controller (UPFC) in Jiangsu grid of China, a higher requirement is put forward by power grid analysis on the accuracy of modelling and simulation. UPFC has different characteristics under different control strategies, and Modular Multilevel Converters (MMC) simulation is a difficult task. In order to study its dynamic characteristics, an electromagnetic model of UPFC based on MMC was proposed, which could simulate its different control strategies and relative dynamic characteristics. The proposed model was realized in PSD-PSModel program and verified using IEEE39 case. The simulation results show that the proposed UPFC model could provide effective tool for analysing the UPFC's dynamic characteristics.