Research on VSC-MTDC for grid integration of wind farm

Developing the Voltage Source Converter (VSC) based multi-terminal HVDC (MTDC) grid or a DC grid has re-emerged in recent years due to the increasing penetration of renewable energy generation and the need for alternative power routes. This paper studies connection topologies of offshore wind farm Grid integration via VSC-MTDC with a focus on their dynamic responses to disturbance, e.g. Grid fault, wind farm failure. The simulation results in PSCAD show parallel connection is more robust than series connection in terms of transient stability when a VSC-MTDC system recovers from faults in AC system and shut-down of a wind farm offshore converter. An optimisation of PI control parameters in VSC-MTDC is also performed using the Simplex method. It is found that the optimisation brings improvement to dynamic stability of the system.