Abstract: The control system of wind turbine is a key component to the VSCF wind power system.It can guarantee the optimum operating state and accurate control.Computer control technology and network control greatly improve  the reliability and intelligence of wind turbines.This paper introduces Ethernet for Control Automation Technology (EtherCAT),and designs main controller of the wind power system,which  improves the capacity of real-time control and data transmission.In addition the hardware and software schemes are given.

Key words: Ethernet for Control Automation Technology, wind turbine, EtherCAT slave controller, main controller