Unbalanced load in variable speed generators in hydro power plants

Grid operators are responsible for providing customers with electrical energy at a high quality standard. The fluctuation of energy consumption compared to the more steady production makes the operation of electric power systems more difficult, especially in night hours. At the same time frequency and power generation have to be kept within the tight limitations. Variable speed motor/generators in hydro power plants can be a useful application compared to fixed speed generators to increase the stability of the network. Since 1990 several variable speed units have been installed in Japan and have proven to contribute to system stability due to their fast active and reactive power control function. One of Germany's largest pump storage power plants (Goldisthal/Thuringia) will be equipped with two variable speed generators with a rated power of 340 MVA designed by VA TECH ELIN. Investigations on symmetrical as well as unsymmetrical load conditions in the network and the response of the machine on such loads are necessary for the appropriate design of the motor/generator and its protection devices. not assigned KP: Partner aus der Industrie