To solve the problem of a wind turbine generator having a rotation assist function at low wind velocity in which a semiconductor circuit for controlling generation power and a semiconductor circuit for controlling rotation assist power are utilizing the same switching element and a pair of free-wheel diodes that, since the semiconductor requires withstand pressure design while taking acount of a generator voltage when rated power is generated, a power conversion loss increases during rotation assist at low wind velocity and thereby a package is enlarged, and to provide a small and low-loss circuit performing a rotation assist and generation power control.
The wind turbine generator comprises a generator 2 as a means for generating power by receiving wind through a windmill 1, a means 3 for storing generated power, and a rotation assist control means 4 utilizing a semiconductor having a breakdown voltage lower than that of the generation power storage means 3 for controlling the windmill to rotate at low wind velocity wherein on-resistance or a saturation voltage of the semiconductor can be lowered during rotation assist control while reducing the size and the loss during the assist.
Hiroki Naito
Daisuke Nagano