Methods and systems of advanced yaw control of a wind turbine

A retrofit system for a wind turbine including a tower, a nacelle mounted to the top of the tower, a turbine control unit, and one or more wind direction sensors attached to the wind turbine, the retrofit system comprising:

• a retrofit data communication and processing unit configured to be communicatively coupled to the turbine control unit;
• wherein the retrofit data communication and processing unit receives a first signal representing an initial nacelle yaw position of the nacelle relative to the tower and a second signal representing a desired nacelle yaw position of the nacelle relative to the tower;
• wherein the retrofit data communication and processing unit provides auxiliary control over the wind turbine by disconnecting a relative wind direction signal traveling between the one or more wind direction sensors and the turbine control unit, determining a virtual relative wind direction signal from the current nacelle yaw position and the desired nacelle yaw position, the virtual relative wind direction signal causing the turbine control unit to drive the nacelle to the desired nacelle yaw position, and sending the virtual relative wind direction signal to the turbine control unit instead of the relative wind direction signal.