The technology developments for wind power generation have attracted wide attention over past decades. One of the most interested topics is variable speed control that enables a wind turbine system to achieve the optimal efficiency of power conversion from the aerodynamics to electricity. This paper presents a 2-DOF control scheme which can achieve a maximum power generation based on the continuously variable transmission and maximum power point tracking. The variable transmission composed with a planetary gear train is controlled by an electric motor to realize the optimal tip speed ratio. This transmission control ensures the maximum energy conversion from aerodynamics to mechanics. Furthermore, the power conversion in a DC generator is also controlled for tracking the maximum power point. Thus, this 2-DOF control scheme aims to obtain the maximum power generation of an overall wind turbine system.