Electricity should flow constantly, even during the energy transition, when the voltage is on a rollercoaster ride due to the ups and downs of the grid load. MR and its partner Omexom have therefore installed MSCDN technology at Amprion’s Sechtem substation that takes over from decommissioned power plants the important job of supplying grid-stabilizing reactive power.
Lights get turned on in the evening, as do many ovens, washing machines and televisions. If, at the same time, masses of electric cars are connected to the mains, voltage can plummet. Or it jumps through the roof when a lot of renewable energy producers pump green energy into the grid in good weather. Until now, this was the time for fossil and nuclear power plants, which flexibly balanced out voltage fluctuations using reactive power. With their discontinuation and the expansion of renewables, which ensure more volatility in the grid, this indispensable job is becoming vacant.
However, one candidate for the vacancy has already proven itself: the “Mechanically Switched Capacitor with Damping Network” or MSCDN technology. These five letters stand for an innovative plant that works with a mechanically switched capacitor bank including a damping network. “In the future, MSCDN systems will be increasingly needed to provide capacitive reactive power or compensate voltage fluctuations. They improve voltage quality and dampen resonances in the grid; and they also work efficiently and require little maintenance,” explains Uwe Jäger, Director Business Area Substations at Omexom.
Sechtem: Fit for more grid power
MR’s Power Quality division and Omexom Umspannwerke GmbH have further developed MSCDN for demanding high and extra-high voltage transmission grids, and substations of three of the four German transmission system operators are already working with it. In April of this year, the partners connected a GRIDCON® MSCDN system for 380-kilovolt electricity to the grid at the Sechtem site of the operator Amprion. The substation in the Bornheim district between Cologne and Bonn is an important hub where various line corridors meet — a favorable location for grid control.
“MSCDN systems improve voltage quality and dampen resonances in the grid; and they also work efficiently and require little maintenance,”
Uwe Jäger, Director Business Area Substations at Omexom
“With the MSCDN plant, we are meeting the increased demands on the electricity grid. We are absorbing the dismantling of the coal-fired power plants in the Rhineland and the demand for reactive power, which is also increasing due to the growing number of transits in the transmission grid,” says Dr. Daniel Eichhoff to justify the million-Euro investment. The Head of the Stations Department at Amprion is satisfied with the result: “The system has been working very reliably since commissioning and the cooperation with MR and Omexom was characterized by a high degree of trust and an open, transparent exchange. We already know and value each of the companies as reliable partners from previous projects.”
Further MSCDN plants by 2030
The MSCDN system is a component of the modernization that has been underway in Sechtem for several years, and fits into the sophisticated mix of static and dynamic compensation measures. The static technology, which can be switched either on or off, regulates the base load. “This applies to the MSCDN system, which boosts voltage, as well as to voltage-reducing choke coils that work with powerful tap changers from MR,” explains Eichhoff.
“With the MSCDN plant, we are meeting the increased demands on the electricity grid. We are absorbing the dismantling of the coal-fired power plants in the Rhineland and the demand for reactive power, which is also increasing due to the growing number of transits in the transmission grid.”
Dr. Daniel Eichhoff , Head of the Stations Department at Amprion
Dynamic systems such as STATCOM (power converters) and rotating phase shifters continuously and flexibly regulate the remaining, temporarily changing load. In addition to the renovation of the entire substation in Sechtem, new transformers were also installed there to cope with the energy transition and the growing demand for electricity. Amprion uses a comprehensive transformer monitoring system to monitor, renew and expand its transformer fleet. Growth is not only certain at this point, announces Dr. Eichhoff: “The MSCDN system in Sechtem was not our first and not our last. Two more are under construction and we are planning several more at Amprion sites by 2030.”