Key Technologies of Three-terminal DC Transmission System Based on Modular Multilevel Converter
A three-terminal DC transmission system based on modular multilevel converter (MMC) is developed to solve the problem of power supply for distributed islands or cities.The system,with flexible features,may generate high quality output voltage and reduce construction costs and power losses in the converter stations.However,the three-terminal DC system based on MMC faces more complex situations in operation and its control strategies.In this paper,the mathematic model of three-terminal DC system based on MMC is deduced.Then according to the structure of MMC,a method of carrier phase-shift SPWM is introduced.As the system-level control,the decoupling controller for threeterminal DC system based on MMC is designed.A multi-point DC voltage control strategy based on DC voltage error method,which doesnt need communication between converter stations,is proposed to improve the system reliability.By simulation with PSCAD/EMTDC,the feasibility and effectiveness of the proposed model and control strategies are verified.
Modular Multilevel Converter (MMC):threeterminal DC transmission system:control strategy:multi-point DC voltage control
Xiaodong Yang Chengyong Zhao Jing Hu, Jing Wang Liu Yang
Key Laboratory of Power System Protection and Dynamic Security Monitoring and Control under Ministry of Education North China Electric Power University Beijing,China
国际会议
威海
英文
499-503
2011-07-06（万方平台首次上网日期，不代表论文的发表时间）