... 1-4244-0493-2/06/$20.00 ©2006 IEEE. 2Unlike constant -speed control, a variable- speed control can adjust the speed of the turbine as the wind speed changes, so as to operate at the peak of the ... apparent that, when operating at a constant speed, the power coefficient will be maximum at only one wind speed. DC Bus Control of Variable Speed Wind Turbine Using a Buck-Boost Converter ... λ is shown in Fig.1. For constant -speed operation, the turbine speed (mΩ) is forced to remain constant. Thus, as the wind speed changes, the tip speed ratio and the power coefficient...