Transmission system operator 50Hertz will develop its site near Bad Lauchstädt, in the south of Saxony-Anhalt, into an important hub for the transmission of renewable energy. Large investments in substation technology are planned that will soon be implemented together with regional and international partners. A total of four high-tech systems for so-called reactive power compensation will help stabilise the voltage and therefore support reliable electricity transmission. Now that the contracts are placed, preliminary work has started. The Lauchstädt substation is, among other things, the starting point for the South-West Interconnector ('Thuringian Electricity Bridge') that transports renewable electricity to the south.
50Hertz charged US manufacturer General Electric Renewable Energy (GE) with the delivery of two static synchronous compensators (STATCOMs). Additionally, Maschinenfabrik Reinhausen (MR), located in Erfurt, Thuringia, was awarded the contract to construct two so-called MSCDN systems in cooperation with Omexom EBEHAKO GmbH from Zwickau in Saxony. Together, the contracts are worth several millions of euros.
Dr Frank Golletz, Chief Technical Officer at 50Hertz: 'If we want our future power supply to come almost exclusively from renewable energy sources, our grids require reliable as well as innovative operating equipment for voltage and frequency stability. Simply put, the reactive power compensation systems that we ordered will provide the 'lubricant' for smooth and secure electricity transport. The Lauchstädt site is extremely important as this is where the high-capacity South-West Interconnector in the direction of Bavaria, also called the 'Thuringian Electricity Bridge', starts and other high-voltage power lines converge as well.'
The systems are required because in the future fewer thermal power stations with large generators will contribute to automatic voltage regulation by providing reactive power. For electricity generated from renewable sources, mainly wind and solar power, the reactive power needed for voltage stability that was previously supplied by large power plants needs to be replaced. This is the function of the STATCOMs and the MSCDN systems, which will be installed at specific positions in the transmission grid. Electricity can only flow through an alternating current grid with the right active and reactive power ratio. This ratio is essential to create and break down a magnetic field 50 times per second so that the voltage is maintained during electricity transmission. If there is too much reactive power in the grid, less electricity is transported, whereas if there is not enough reactive power, the voltage drops, which can lead to disturbances in the electricity supply.
The two STATCOMs (static synchronous compensators) to be constructed by GE provide dynamic reactive power and have a capacity of +/- 300 MVAR each. Their completion is planned for 2025 and 2027.
The two reactive power compensation systems from Maschinenfabrik Reinhausen / Omexom also have a capacity of 300 MVAR each. MSCDN stands for Mechanically Switched Capacitor with Damping Network. Such systems provide static reactive power. Complementation as well as commissioning are also planned for 2025.
Johan Bindele, Grid Integration Leader at GE Grid Solutions: 'GE's STATCOM system is highly reliable and can be integrated both into existing and new infrastructure. It also offers an economical solution to 50Hertz.'
Wilfried Breuer, Managing Director of Maschinenfabrik Reinhausen, is pleased: 'The energy transition is our trademark. With our MSCDN systems, such as those in Lauchstädt, we demonstrate our extensive system competence in our own country. Our team of experts in Erfurt has already installed this technology several times worldwide and will also ensure the reliable completion in Saxony-Anhalt.'
Frank Westphal, CEO of Omexom Deutschland: 'We at Omexom are very proud that we can carry out this project together with Maschinenfabrik Reinhausen to implement a technically challenging solution for voltage stability in our grids. Our employees will assemble the MSCDN systems from MR in the substation, thus contributing to the grids of the future. Using technologies such as these, we are converting energy systems so that they can supply sustainable electricity.'
Altogether, 50Hertz will install dozens of STATCOM systems and other voltage stability and restraint systems at many sites in the years to come. A corresponding capacity of more than 12,000 MVAR was confirmed in the 2035 Grid Development Plan of 2021.