This paper is based on designing a modified rotor for a drivetrain in a Type-III wind turbine system for maximum power generation to work effectively under low and high wind speed and its variation. In this paper, three drive trains are designed for the gearbox to provide regulated torque and thrust force. For time to time variation in wind speed the voltage sag and during over speed condition voltage swell problem can be solved by using this modified design. The pitch control, gearbox, and yaw of the wind turbine are basically focused on modification. Mainly the gearbox for the rotor causes sluggish motion of the rotor during low wind speed. This paper ex-plained the design of modified rotor control for the gearbox in DFIG based (Type-III) wind turbine. Also in this paper how the modified rotor system can be helpful for reactive power control is highlighted with the comparison with existing models. For designing MATLAB Simulink platform is taken and validated using CFD Mechanical design analysis. Using these types of modified drive trains maximum power for the wind turbines is enhanced by 40-60% of its reference value.