Fuchstal glows

Isolated grid operation in a converter-dominated medium-voltage grid.

Prof. Dr.-Ing. Georg Kerber

The energy transition has resulted in fundamental changes in the energy supply. Power generation is increasingly based on millions of small, converter-based generators. Accordingly, essential system services of the large power plants with synchronous generators are falling away.

In the Fuchstal real laboratory, practical tests are being used to clarify the question of how stable grid operation is possible in practice in a grid without a central control structure, which is fed and loaded exclusively by power converters. In the sub-project "Investigation and modelling of the boundary conditions for the continuous operation of a converter-based stand-alone grid based on renewable energies with sector coupling", it is assumed that the emergency supply stand-alone grid can be operated in a fundamentally stable and safe manner.

Here, the focus is on operation management in the medium to long-term time range and the energy management necessary for stable island grid operation. The operability, interface to the operating personnel for fault location or decision support (e.g. shutdown sequence) is also relevant here, as significantly different requirements apply for this operating case than in normal operation.

Another aspect is the recording and modelling of harmonic interference levels, which can no longer be described with standard methods in the case of a purely converter-based technology. Other important tasks are the planning of the field tests and the overall project coordination.

The research project consists of the following sub-areas:

  • Development of control strategies for grid-forming power converters with integrated battery storage systems
  • Investigations into undesirable interactions and the analysis of the interaction of converter controls
  • Consideration of system stability in response to load changes
  • Investigation of protection technologies and selective shutdown mechanisms and evaluation of adaptations to meet the requirements of stand-alone grid operation
  • Critical review of the existing grid parallel operation parameters with regard to future grid stability and review of necessary adjustments or revisions in accordance with technically applicable connection rules
  • Design and evaluation of a control concept for converter-based interconnected grids based on the investigated converter-based medium-voltage grid

General project information:

  • Running duration: 01.08.2023 - 31.07.2026
  • Funded by: Bundesministerium für Wirtschaft und Klimaschutz, BMWK
  • Project executing agency: Projektträger Jülich, PtJ
  • Database: Enargus

Project partner