ABB’s Powerformer high voltage generator will be installed at Vattenfall’s Porsi plant, it was announced recently.

The Powerformer is a new type of generator that can be connected directly to the grid, without the need for a step up transformer (see IWP&DC, April 1998, pp34&35).

The new generator will be rated at 155kV, 75MVA. It will be installed at Porsi on Sweden’s Lule river (shown above), where it will replace one of the existing generators.

Speaking about the new unit, Vattenfall’s head of hydro power production, Goran Hanstrom, said: ‘The unit being replaced at Porsi was due for total renovation in a few years time, but we are now bringing our plans forward.’ He said installing the Powerformer ‘will provide us with an excellent opportunity to learn about the new technology.

‘In addition, we reckon on obtaining considerable benefits through reduced maintenance and increased availability.’ ABB estimates that the fewer components used in the Powerformer system will improve efficiency by 0.5%, increase availability by 0.6% and reduce maintenance costs by 10% — an overall life cycle cost reduction said to be 30%.

The Porsi unit is the second Powerformer unit to be ordered to date. The first, rated at 136kV, 42MVA, is scheduled to enter service at the end of 2000 at a CHP plant in Eskilstuna, central Sweden.