Powerformer/sup TM/-the prototype and beyond

The general concept of Powerformer/sup TM/, a high voltage generator connected directly to the grid, is described. By using high-voltage cable technology it is possible to confine the electrical field to inside the winding and reach high voltage levels on the generator terminals. The prototype high-voltage generator rated at 45 kV, 11 MVA has been operating since spring 1998. The accumulated operating time is now 3700 hours. Some test results are presented. Contracts for two Powerformer generators have been granted, one turbogenerator rated at 136 kV, 42 MVA and a hydropower generator rated at 155 kV. 75 MVA. Some data and background information for these two units is presented.