The company will supply two pumped storage units with variable speed, each with 380MW rated power in turbine mode, two asynchronous motor generators with a rated capacity of 420 megavolt ampere, frequency converters, control system and the hydraulic steel structures.
Thanks to their variable speed, the pumped storage units of Venda Nova III can adapt their number of revolutions continuously and take capacities from the grid in the range between 319 and 380MW. Units with fixed speed do not provide this range – their pumping power is regulated with the aid of further units or plants. For the development of wind power, whose supply capacities are intermittent and not precisely predictable, providing flexible reserve, however, plays a crucial role. In combination with variable speed pumped storage, wind power plants become more reliable and more profitable.
“Venda Nova III is a milestone in hydro power: variable speed technology supports direct grid control,” commented Dr. Siegbert Etter, Executive Vice President Technology of Voith Hydro Holding. “In the era of renewable energies this is the new role pumped storage plants are playing.”
Venda Nova III is expected to be connected to the grid in early 2015 to support wind power in Portugal.