Completed Research topics at the Professorship Power Transmission Systems

The effects of large-scale extended-duration blackouts represent a potential national catastrophe and threaten many of the essential services around which modern society is based. Through the operation of decentralized generation in island networks, critical services such as hospitals, fire services and police services could be maintained. The goal of the research project is the development of a generic scalable concept for stable island network operation utilizing decentralized generation, which is applicable to all voltage levels. Following the recovery of the main power system, the resynchronization and reconnection of the island network should be performed automatically without disturbance to grid operation.

In recent years research activity on electrical cars has increased drastically due to the scarcity of oil and the climate change. Electrical cars will be charged through the power outlet. This will lead to an increase of power consumption and present a new challenge for the power grid. The batteries of the electrical cars can help to even out the peak demand and congruence the energy generation and consumption. Electrical vehicles can also help to integrate renewable energies (e.g. photovoltaic systems) into the power grid. The Institute of Power Transmission Systems is researching on concepts on integrating electrical vehicles in to the power grid and analysing the influence this will have on the power grid.

Increasing regenerative power sources installed in low voltage grids tend to cause overvoltage problems due to the reverse power flow direction. Consequently, regenerative sources need to be turned off temporarily and on the long term, the grid infrastructure would have to be extended by the utility company. Additionally, the increasing number of grid connected power electronic systems causes a high level of reactive power flow and harmonics in the grid affecting power quality. By means of an innovative communication and system concept the distribution network quality could be cost-effectively, locally and promptly monitored. Locally controlled inverters could contribute to improve the network quality by means of voltage stabilization, reactive power compensation and filtering/ compensation of harmonics. Thus, the capability to accept, integrate and transmit higher quantities of decentralised generated power can be improved.

Within the project NetzQ a corresponding device technology is developed and this approach will be tested exemplarily in two subnetworks (city, rural region).