Fraunhofer ISE inaugurates Center for Power Electronics and Sustainable Grids

The Fraunhofer Institute for Solar Energy Systems ISE of Freiburg, Germany has officially inaugurated its new Center for Power Electronics and Sustainable Grids in the industrial area in northern Freiburg. With a propriety connection to the 110kV high-voltage grid and 40MVA transformer, the new center is said to offer a unique research infrastructure that enables it to meet the growing demands on power electronics.

“In the future energy system, electricity will be provided not by a small number of conventional power plants but by many wind and solar power plants with fluctuating electricity generation. Thus, power electronics will assume a dominant role at all grid levels,” says professor Hans-Martin Henning, director of Fraunhofer ISE. “Moreover, we require new components and functions, which enable inverters to provide stability and control for the power grid of the future,” he adds.

The development of new power electronic components and systems with more advanced properties is one of the main challenges. To achieve this, silicon carbide (SiC) and gallium nitride (GaN) power semiconductors will be increasingly implemented. These devices operate with high frequencies, making power converters with higher power densities possible.

Also, new grid services will be investigated, especially with respect to the stability of future, inverter-based grids – focusing not least on procedures for testing the grid assistance capabilities of inverters, e.g. voltage and frequency stability. Other properties, such as active resonance damping in power plants and power grids or the grid-forming characteristics of inverters will be addressed in the near future.

Expansive lab facilities

The new center adds an additional 3000m2 of lab and office space to Fraunhofer ISE. Three laboratories cover the various thematic areas of power electronics:

The Power Converters Lab develops systems for the low-voltage range (e.g. photovoltaic systems, batteries, electric mobility and aviation).
The Medium Voltage Lab (equipped to operate systems up to 20MVA power) develops and tests power electronics for the medium-voltage range.
The Multi-Megawatt Lab can perform multiple tests in parallel, with different test blocks allowing operation ranging up to 10MVA and 1000V, i.e. wind generators, large battery storage systems or combined heat and power (CHP) systems.

In the Multi-Megawatt Lab, components and systems are tested up to 10MVA.

Picture: In the Multi-Megawatt Lab, components and systems are tested up to 10MVA.

The total actual power of 40MV is equivalent to the power supply of a small city with about 50,000 inhabitants. The center has its own proprietary research grid, which is completely disconnected from the supply grid of the surrounding vicinity. Additionally the center’s R&D infrastructure will be enhanced by the Digital Grid Lab, which deals with simulations of load profiles and energy management systems. In this lab, Fraunhofer ISE will be able to further its expertise in grid simulation and real-time communication and investigate the performance of devices and systems at important grid nodes. Still in construction, the Digital Grid Lab is a further development of the existing Smart Energy Lab of Fraunhofer ISE (located in its main building).

Development, testing and certification

With the independent TestLab Power Electronics (certified according to DIN 17025.2005), Fraunhofer ISE is now widening its service range for industrial customers to include development, testing, refurbishment and certification services for components up to the multi-megawatt and the medium-voltage range. With a specially designed over- and under-voltage ride-through system enabling dynamic voltage variations, specific grid situations like over-voltage and under-voltage can be simulated or particular grid impedances can be emulated.

With four different test blocks and independent transformers, several aggregates can be tested either separately in parallel or together in interconnected micro grids.

“In these facilities, we can optimally address future research topics, for example inverter-based grids, hybrid power supplies and large storage systems,” says Dr Olivier Stalter, division director of Power Electronics, Grids and Smart Systems at Fraunhofer ISE.

The project was supported by the German Federal Ministries for Economic Affairs and Energy (BMWi), for Education and Research (BMBF) and for the Environment, Nature Conservation and Nuclear Safety (BMU), which provided a total of €10m to Fraunhofer ISE. Fraunhofer ISE itself invested a further €5m in the new laboratory.

Tags: Fraunhofer ISE Power electronics GaN SiC

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