Research

Electric Power and Energy Systems – Renewable Energy

The research topics related to electric power systems are mainly related to the renewable energy sources and their integration into both transmission and distribution systems. In transmission systems the provision of ancillary services by wind turbine parks and large industrial consumers is investigated, e.g. the contribution to primary frequency control and inertial response. With respect to distribution systems, a lot of attention has been paid to power quality and in recent years pioneer research on microgrids has been carried out. While we started with short-term control aspects (e.g. primary frequency control), we also investigate control and energy management over longer time frames, e.g. unit commitment problems in microgrids, including storage and, thus, links with thermal networks. This also includes economic and environmental aspects and concrete applications, e.g. the optimisation of the energy system of business clusters. Both the short-term control aspects and long-term energy management is investigated for several applications, i.e., the chemical process industry, power-to-gas installations and wind farms. One of the challenges of integrating renewable energy sources in power grids is their intermittent character which can be compensated by (e.g.) demand-side response, i.e. by the flexibility of electric power consumption. The clustering of individual demand-side response units into a so called virtual power plant is a more recent line of research. An aggregator (i.e. flexibility service provider) combines energy consuming and producing units with different flexibility parameters into a standardised market product or ancillary service.

With respect to the electric power generation based on renewable energy, we have a long research tradition in wind energy. We focus both on the machine-side control, to increase the energy yield with advanced control methodologies, and the grid-side control, to provide ancillary services to the grid or to offer power quality compensation. In particular the dynamic conditions are treated, e.g., due to fastly varying wind speeds and variable grid conditions.