Novel Power Electronics Systems for Wind Energy Applications: Final Report; Period of Performance: August 24, 1999 -- November 30, 2002

The objective of this work was to develop new approaches to the power electronics of variable-speed wind power systems, with the goal of improving the associated cost of energy. Of particular importance is the converter efficiency at low-wind operating points. Developing converter approaches that maintain high efficiency at partial power, without sacrificing performance at maximum power, isdesirable, as is demonstrating an approach that can use emerging power component technologies to attain these performance goals with low projected capital costs. In this report, we show that multilevel conversion is an approach that can meet these performance requirements. In the wind power application, multilevel conversion proves superior to conventional converter technologies because it iscallable to high power and higher voltage levels, it extends the range of high converter efficiency to lower wind speeds, and it allows superior low-voltage fast-switching semiconductor devices to be used in high-voltage high-power applications.