Mitsubishi Electric completes tests on World’s first 900-MVA-class turbine generator to use indirect hydrogen cooling
Mitsubishi Electric announced today the successful completion of verification tests on its VP-X turbine generator for thermal power plants, the world’s first generator in the 900 MVA class to use indirect hydrogen cooling for stator conductors. Cooling is achieved with hydrogen gas introduced from outside of the main insulation. The VP-X achieves an extra-high efficiency rating of 99%, placing it in the world’s highest class of turbine generators that offer highly sustainable operation. Mitsubishi Electric enhanced cooling performance in the VP-X by improving main insulation and cooling gas ventilation without incorporating a water-cooling system for the stator winding. Until now, all large-capacity turbine generators in the 900 MVA class have relied on water-cooling.
Mitsubishi Electric’s VP-X also boasts a simplified design that will help improve the appearance of power plants, as well as lower the requirements for maintaining and operating turbine generators. The overall size is 20% smaller than conventional indirectly hydrogen-cooled generators. In addition, both the footprint and frame diameter are smaller, making transportation easier. Elimination of a water-cooling system for the stator winding helps to simplify maintenance. In addition, a new parallel-manufacturing method for the stator core and stator frame shortens delivery time. A series of VP-X generators will be launched commercially in April 2015.