Machine and Converter Reliabilities in Wind Turbines

Electrical Machine/Converter combinations are used in a variety of applications, from powers of Watts to MegaWatts. Some applications, such as propulsion and generation, have high reliability & availability requirements. Modem large wind turbines incorporate variable pitch blades and a variable speed Generator, which feeds the Grid through a Converter and have a need for high reliability & availability. There are a number of configurations of generator and converter intended to provide optimum performance for present and future wind power. This paper describes an investigation into the reliabilities of Generators and Converters in such configurations and is based on failure data collected in Germany and Denmark. The paper draws conclusions about which configurations have the higher reliability and identifies the subassemblies of the turbines which require attention for the future design of high reliability wind turbines. Recommendations are made about how designers and operators of wind turbines can increase their reliability by the choice of Concept and the operating regime