Award-winning master's thesis on energy-efficient switchgear concept
At this year's 58th OVE Energy Technology Conference in Linz, M. Sc. Arno Bernhardt, a member of staff at the Electrical Apparatus and Switchgear Group at TU Ilmenau, presented a highly regarded energy-efficient switchgear concept. He had analysed and conretely described the innovative concept as part of his master's thesis "Modelling, simulation and design of a hybrid DC low-voltage circuit breaker".
Due to the steady progress of the energy turnaround and the associated increasing decentralization of the generation structure of electrical energy, locations of electricity demand and locations of electricity generation are coinciding more and more frequently. This opens up many opportunities to use new concepts in the field of electrical energy supply. One example of this is local stand-alone grids at building or neighbourhood level, also known as microgrids. Together with the use of regenerative energy sources such as photovoltaic systems, they enable a certain independence from the public power grid. At the same time, the direct use of the direct current provided by renewable energy plants and the resulting significantly shorter transmission distances also offer significant potential for improving the efficiency of the electrical energy supply.
The basic prerequisite for exploiting these advantages is high-performance DC switchgear. At the same time, it should be capable of assuming protective functions for persons and systems. Conventional mechanical switchgear, as currently used, is not suitable for the requirements associated with direct current.
Innovative approach implemented in practice
Experts consider the concept of the hybrid switch to be a promising approach for a high-performance DC switching device. This concept combines two fundamental switching device technologies: that of mechanical switching and that of power electronic switching. This ensures that electrical energy can be transmitted with extremely low losses and, if necessary, that this transmission is interrupted just as safely, quickly and reliably.
In his master's thesis at the Electrical Apparatus and Switchgear Group, which was supervised by the its head Prof. Frank Berger, Arno Bernhardt dealt with the structure, function and modelling of such a hybrid switch. He identified central components of the hybrid switch, such as its control circuit. This circuit is the basic component of the hybrid switch and was developed as part of the thesis. The central process for the hybrid concept is the so-called commutation process. This process describes the transfer of current from the mechanical switching device to the power electronic switching device. Without the successful completion of this process, the concept of the hybrid switch cannot develop its effect. Accordingly, in the course of his work, Arno Bernhardt developed a commutation model that is as simple as possible, which can be used to investigate fundamental relationships of the commutation process.
Awarded the Professor Werner Rieder Prize
Due to the high quality and relevance of his work for innovative energy supply systems, Arno Bernhardt was honoured with the Professor Werner Rieder Award at the OVE Energy Technology Conference 2021. The prize is endowed with 2000 euros.
The OVE Austrian Electrical Engineering Association networks companies and institutions as well as experts and interested parties from the entire field of electrical engineering. Every year, the association holds its power engineering conference at different locations. In 2021, the conference focused on environmentally friendly technologies for power supply. High-ranking experts from industry, energy companies and grid operators as well as from research and politics discussed and presented innovative developments and concepts in the field of electrical energy supply.