German transmission system operator Amprion commissioned Siemens Energy with the construction of two SVC PLUS series static synchronous compensator (STATCOM) systems to further stabilize the German transmission power grid. The plants will be in Polsum (North Rhine-Westphalia) and Rheinau (Baden-Württemberg). Both systems are designed for a reactive power range of +/- 600 Mvar making them among the most powerful systems in the world. In addition, the STATCOMs will feature grid-supporting control mechanisms allowing the systems to efficiently compensate for increasing voltage fluctuations in the electrical transmission network.
The share of renewable energies is growing worldwide. However, their volatile feed-ins put significant strain on the power grids. Due to the geographical arrangement of renewable energy generation, the distance to the consumption centers is growing. In Germany, for example, the space is growing between large wind farms that feed into the energy grid in the north and load centers in other parts of the country. This makes the transmission network more susceptible to voltage fluctuations and interference. For a long time, large power plants have provided the reactive power necessary for grid stabilization. However, due to the energy transition many of these conventional power plants, which are operated with nuclear or fossil fuels, are being taken off the grid.
As a result, transmission system operators like Amprion set up STATCOM systems at important grid nodes. They compensate for the voltage fluctuations by regulating the reactive power as required, keeping the grid voltage in a stable range. In addition, the expansion of renewable energy generation allows greater use of power lines, reinforcing the need for increased reactive power compensation. This requires STATCOM systems with increasing capacities up to +/- 600 Mvar reactive power.