Grid Frequency Control for LCC HVDC Link Connected Wind Farms

In this paper we consider the design for the offshore grid frequency control in a DFIG-based wind farm with LCC HVDC link connection. The control approach is based on using the grid frequency to regulate the HVDC DC-link current and hence control the power flow in the system. The dynamic equations are derived and grid frequency controller is designed. The mathematical analysis and the control design are verified through PSCAD simulations. Good modelling agreements are obtained for the closed loop system and the work provides a good basis for wider research investigation into wind farm operation.