A Wind Turbine with Two Synchronously Rotating Windwheels

Abstract

An objective of improving the efficiency of horizontal-axis wind turbines (HAWTs) is stated. The main restrictions causing less efficient operation of wind turbines with a decrease in wind velocity are described. The operation peculiarities of and the power generation by low- and multiblade wind turbines are subjected to a comparative analysis, based on which a new wind turbine design is proposed. The proposed wind turbine design is based on the classic operation principle of an HAWT and allows a windwheel with n blades to be converted into a windwheel with 2n blades and back without the need to shut down the installation. The peculiarity of the new design is that two uniaxial windwheels are installed on a common shaft through a transfer hub, using which the position of uniaxial windwheels with respect to each other can be changed by placing the blades of the second windwheel right behind or in between the blades of the first windwheel. As a result, the wind turbine operation mode is divided into two main modes: one with n blades at higher windwheel rotation speeds and the other with 2n blades at lower speeds. The windwheel control logic depending on the external conditions is also outlined. Its essence consists in producing a control signal for the hub proceeding from the actual wind velocity and the second windwheel's actual position. The generated control signal is applied to the electric motor through a programmable logic controller for changing the position of the second windwheel. The main results of calculations containing the comparative technical and economic gains from using the proposed solution are presented.