The Switch Introduces Wind Power Drive Train

Switch has developed a drive train for the wind power business that utilizes an optimized permanent magnet generator (PMG) and full-power converter package. The drive train, The Switch Drive, allows active power extracted from the turbine, as well as the reactive power produced, to be individually and precisely controlled over the entire operating speed range.

"The Switch Drive not only offers substantially improved costs, but the efficiency of the PMG at partial speed is superior to that of conventional double-fed or squirrel-cage systems. This technology has become the obvious choice for the industry and in some operational points, wind turbines using our PMG and full-power converter are seeing up to 20% higher partial load efficiency, yielding more energy," said Jukka-Pekka Mäkinen, president and CEO of The Switch. "Another advantage of The Switch Drive is its ability to tune itself to individual sites and seasonal conditions."

The PMG is a type of synchronous generator that requires no connections and energy feed to the rotor. Permanent magnets are placed on the rotor to create excitation — a major factor in delivering greater efficiency, as this design virtually eliminates rotor losses. By driving the generator with an optimal power factor using PMG technology, stator-side losses are also minimized. PMGs do not require any separate excitation systems, thereby reducing cost, simplifying the system, and improving system efficiency. Further, no slip rings are used, greatly reducing maintenance needs.

The company has production facilities in Hudson, New Hampshire, that it said position it well to address the needs of North American customers in 2009 and beyond.