High-power converter systems for high-speed generators

For grid connection of high-speed gas-turbines, converters can be used to eliminate the otherwise mandatory gearbox. Compared to standard drives, different requirements are imposed on the converter. In this paper, the application of different converter types for a typical gas-turbine generator system are investigated. After selecting suitable topologies and devices, the expected system power losses are calculated using a simulation tool that comprises measured power dissipation for the semiconductors. The loss calculations are done separately for the generator and the grid side converter. Finally, the results are compared and assessed.