Research profile of Electric Power Engineering Section

The research topics of Electric Power Engineering Section are oriented towards the challenges facing the electrical energy system within the framework of the energy system transformation with the expansion of renewable energies, the phasing out of nuclear energy and coal, and the transport system transformation with the expansion of electromobility, and towards the resulting changes in system behaviour.

MODELLING AND SIMULATION OF ELECTRICAL ENERGY SYSTEMS

  • Modelling of conventional and modern equipment and controllers in electrical power supply systems for stationary operating conditions as well as for RMS and EMT simulations
  • Development of freely parameterisable integrated transmission and distribution network models based on synthetic distribution network models
  • Investigation of stationary system states
  • Quasi-stationary simulations of extensive energy supply networks (RMS simulations)
  • Transient simulations of the electrical energy system (EMT simulations)
  • Efficient simulation of electrical energy systems using empirical as well as mathematical order reduction methods

OPTIMISATION OF NETWORK PLANNING AND SYSTEM OPERATION

  • Modelling, approximation, convexification, relaxation and solution of linear, quadratic and generally non-linear optimisation problems in the field of electrical power supply, taking into account various objective functions and constraints as well as mixed-integer variables and discrete decision logic
  • Power plant deployment and redispatch optimisation in energy and balancing power markets, economic optimisation of balancing power activation
  • Security Constrained Optimal Power Flow taking into account the switching states of lines, transformers
  • Optimised network planning for distribution networks
    • Development of short, medium and long-term cost-optimised network expansion strategies, taking into account future supply expenditures and existing network infrastructure cross-voltage level network planning in the high and medium voltage level
    • Development of innovative planning concepts to reduce the need for conventional grid expansion
    • Location optimisation of substations

FREQUENCY CONTROL AND GRID CONTROL COOPERATION

  • Frequency stability with investigation of frequency control in power grids under the challenge of an increasing displacement of conventional thermal power plants and an increased penetration of volatile feed-in from renewable energies via inverters
  • Simulation of frequency control and control power provision in the grid control cooperation under consideration of congestion management
  • Economic optimisation of balancing power activation

ELECTRICITY MARKET SIMULATION

  • Modelling and simulation of the continental European interconnected grid in an integrated grid and energy market simulation
  • Assessment and evaluation of technical and economic influences and their effects on the European electricity market
  • Evaluation of the transmission networks for current and future expansion, generation and load scenarios
  • Planning of grid expansion measures taking into account current forecasts for the development of the European interconnected grid and deriving recommendations for action

SHORT CIRCUIT CURRENT CALCULATION

  • Influence of power electronic equipment/generating installations on the short-circuit current level, the short-circuit current characteristics and the short-circuit current time curve
  • Analysis of the effects on the application of the short-circuit standard IEC 60909 and on the simplified calculation of the short-circuit current characteristics described therein using factors and the central characteristic Initial short-circuit alternating current

HARMONICS AND NETWORK RESONANCE ANALYSIS

  • Resonance mode analysis (RMA): Calculation of parallel and series resonances in power networks with the associated participation factors and sensitivity analysis
  • Allocation of harmonic current levels and voltage levels according to IEC and VDE
  • Analysis of the effects of grid expansion on the resonance behaviour of the electricity grids and the allocation of harmonic current levels and voltage levels

GRID INTEGRATION OF CONVERTER SYSTEMS

  • Investigation and evaluation of grid-following, grid-forming and grid-supporting converter control concepts
  • Calculation and analysis of harmonic stability in electrical energy systems
  • Stability studies and assessment of stability improving measures by means of RMS and EMT simulations
  • Synchronisation techniques of converter systems for symmetrical and asymmetrical operating states
  • Development of control concepts for Fault Ride Through (FRT)

NETWORK AND SYSTEM IMPACT OF E-MOBILITY

  • Analysis and evaluation of simultaneity and properties of charging profiles according to vehicle models
  • Integration of electric vehicles in the distribution networks
    • Investigation and development of load management with regard to network-related loading
    • Assessment of the need for network reinforcement and expansion
    • Analysis of the possibilities of grid-compatible combination with renewable energies
  • Forecasting network utilisation and harmonic load due to increasing integration of charging infrastructure in distribution networks

CONTACT

Prof. Dr.-Ing. habil. Lutz Hofmann
Professors
Prof. Dr.-Ing. habil. Lutz Hofmann
Professors