Hybrid excitation topologies of synchronous generator for direct drive wind turbine

An analysis of Hybrid Excitation Synchronous Generator (HESG) topologies for a direct drive wind turbine is investigated. Through an optimization process, the topologies of HESG are compared regarding the cost and the total losses. The optimizations are performed at the nominal on-load operating point of the generator. The trade-offs between each topology are analyzed according to a set of Pareto fronts. An instrumented prototype of 900kVA approves the design process. Finally, the best Pareto optimal solutions are compared during an experimental operating cycle of the direct drive wind turbine. The efficiency improvement emphasizes the interest of the design by optimization.