Patent ID: 8008797
Filing Date: 2011-08-30
Classification: H02P

Abstract:
1. A system for converting wind power to electrical power comprising a transmission module with multiple power flows to an output and a first generator coupled to the output, wherein the first generator operates at substantially constant speed for the multiple power flows, wherein the first generator receives excitation current at a frequency controlled by a power grid and wherein the electrical power is provided to the power grid, wherein the first generator is mechanically coupled to the transmission module and electrically coupled to the power grid selectively through a switching module; also comprising a controller for controlling the transmission module and the switching module, wherein the frequency of the excitation current defines a synchronous speed of the first generator, wherein the controller controls gear ratio of the transmission module so that the wind energy provides power driving the first generator at a speed equal to or with positive slip to the synchronous speed for at least two ranges of wind speed.