Siemens technology to stabilize power grid in the Greater Frankfurt Area

Siemens has been awarded an order from the transmission grid operator Amprion for the supply, installation and commissioning of a reactive power compensation system for stabilizing the power supply grid in the Greater Frankfurt Area. In navigating through the energy turnaround, this is how Amprion will tackle the challenges facing the power grid created by an ever-increasing number of fluctuating renewable energy sources feeding power into the grid. The grid operator will use the reactive power compensation system for dynamic voltage stabilization of the transmission grid.

The order includes a latest-generation static VAR compensation system SVC Plus, which has undergone further development by Siemens, among other things to minimize the environmental impact of the system, such as noise emissions and reducing the size of the system to a minimum. Siemens will erect the system in Kriftel, a community in the Rhine-Main region located between Frankfurt and Wiesbaden, and will integrate it there into an existing switchgear system. The volume of the order is around EUR 25 million; the system is scheduled to be commissioned at the end of 2017.

The core of SVC Plus, an advanced Statcom (static synchronous compensator), is its multilevel converter technology. By contrast with other self-commutated converter topologies, the voltage waveshape produced by SVC Plus is practically sinusoidal by virtue of the multilevel technology. This makes the low-frequency harmonic filters often used in earlier solutions superfluous and substantially reduces the space requirements for the overall unit.

The power converter is based on a modular topology. Each converter branch consists of series-connected insulated gate bipolar transistor modules (IGBT power modules). The SVC Plus system for Amprion is designed for a rated capacity of +/- 300 MVAr and laid out in several power converters connected in parallel. Redundant power modules are included in the phases of each converter branch. In the rare event of a fault, these would continue to ensure operation at full rated power without a forced shutdown. Replacement of defective components could then be postponed until the next scheduled maintenance. The average availability for an SVC Plus system therefore far exceeds 99 percent. Siemens has received orders worldwide for more than 50 SVC Plus systems in the last four years alone.