Research On Digital Simulation For VSC-HVDC System And Its Control Strategy

With the development of high power turn-off power electronic components, Voltage Source Converter (VSC) based HVDC (VSC-HVDC) has been realized. In this thesis, the steady-state power characteristics and the control patterns and strategies of VSC-HVDC are analyzed firstly. Then by considering the transient mathematical model and Park transformation, the transient model of VSC in dq0 frame is established and its decoupling controller is also designed. In dq0 frame and with the decoupling controller, VSC can control its active power and reactive power independently. Finally, with the help of PSCAD/EMTDC, under disturbance such as power variation of passive load, the operation characteristics of multi-terminal VSC-HVDC are simulated and investigated.