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Siemens Energy's HVDC PLUS Converter (ALEGrO) in the first HVDC link between Germany and Belgium strengthens the single European electricity market.

©Fraunhofer IEE

Whether on a gigawatt or kilowatt scale, grid-stabilizing power converters can provide power system inertia to stabilize the grid at all voltage ranges.

On Sunday, July 17, Germany harnessed the power of the sun more than ever before when at around 1pm over 40 gigawatts (GW) of solar power were fed into the public grid for the first time. According to data from the Fraunhofer Institute for Solar Energy Systems ISE in Freiburg, this meant that photovoltaic installations generated almost 80% of the electricity being consumed in Germany at that time.

But are PV installations and wind turbines capable of covering the grid’s demand for power system inertia in order to compensate for sudden fluctuations in supply? To date, synchronous machines in large-scale power plants are the main technology used to ensure that the power grid’s requirements in terms of frequency and voltage are met. But there is another way. In the joint research project Grid Control 2.0 (Netzregelung 2.0) coordinated by the Fraunhofer Institute for Energy Economics and Energy System Technology IEE in Kassel, it was demonstrated that wind power and PV installations with grid-stabilizing power converters can also provide power system inertia and can therefore stabilize the system in extreme circumstances.

Prepared for extreme scenarios

“We are convinced that the low-voltage grid – and, in the event of malfunctions, sub-grids – can even be kept stable with a very high number of power converters. But this will require suitable control procedures. We have determined the requirements these procedures should meet and have developed control procedures to ensure that power converters can be used to keep systems stable and secure,” explained project manager Dr. Philipp Strauß, deputy director of Fraunhofer IEE in Kassel, at the project’s closing conference in early July.

During the project, simulations were conducted to evaluate the new control procedures and their stabilizing effect in extreme circumstances, such as a system split, where the grid is split into sub-grid areas across Europe. The teams of researchers were able to demonstrate that the procedures can even help to stabilize the grid in challenging situations like these. (SP)

Source: Fraunhofer IEE

Learn more about grid-forming inverters in our article Grid-Forming Inverters Will Stabilize the Power Grids of the Future.