Coordination between offshore and onshore Voltage Source Converter for Doubly Fed Induction Generator wind farm

Smart power grid fueled by renewable energy is the new frontier of sustainable grid network. Voltage Source Converter based High Voltage Direct Current transmission system is suitable for renewable energy transmission to the grid. VSC-HVDC system is capable of bidirectional electrical power transmission. Voltage Source Converters have one major complication when it is connected to a weak AC grid due to voltage sag, swell or single-phase fault. In this scenario the VSC fails to transfer sufficient reactive power to DFIG farm in bipolar single terminal VSC-HVDC transmission. This results in lower production of power by the DFIG wind farm at high wind speeds. Due to this the power quality degrades further at already weak AC grid. This research has addressed this issue by compensating the reactive power at the offshore Voltage Source Converter. This results in more electrical power production which leads to improving the power factor at onshore bus on the grid side of the Voltage Source Converter. The concept of reactive power compensation offshore to improve power factor at onshore bus is proposed and system models have been simulated in MATLAB Simulink in this research.