New large-scale facility inaugurated for research work on the electrical power supply of the future

While our current power grid is largely based on alternating current (AC), more and more devices are using direct current (DC) internally. This, together with the expansion of volatile renewable energy sources, is leading to an increasing load and instability on the power grid. To address these challenges, two approaches are currently being pursued: On the one hand, the existing AC grid is being optimized by integrating additional energy storage systems. However, once the optimization potential has been exhausted, the power grid must be expanded. Direct current technology is of particular importance here. With its advantages over alternating current, such as high transmission capacity with lower material consumption, it is seen as a promising option for making future electrical energy systems efficient, low in resources and thus ecologically acceptable.

In order to test these potentials of direct current technology in practice and to develop and implement cost-optimal transition scenarios such as the parallel operation of alternating current and direct current networks up to the simultaneous transmission of alternating current and direct current in only one line system, so-called mixed current transmission systems, several research groups in the field of electrical power engineering have been working intensively together at the TU Ilmenau since the 1980s with other groups that are close in terms of content, such as mechanical engineering, automation technology, computer science, physics or economics. This successful work has been consolidated in recent years by three additional endowed professorships and an excellent infrastructure at the Center for Power Engineering. Since 2019, the research work has been coordinated in the Thuringian Energy Research Institute (ThEFI) headed by Prof. Dirk Westermann, which bundles the research of a total of 13 disciplines in all areas of energy, environmental and systems engineering on a national and international level.

Experimental investigations on low- and medium-voltage AC and DC networks

The research focus in electrical power engineering is on experimental investigations of low- and medium-voltage AC and DC networks, their components and their system behavior. Prof. Jürgern Petzoldt:

This makes TU Ilmenau one of the three to four leading institutions in this field in the German-speaking world.

In his keynote address at the opening colloquium, the emeritus professor of Power Electronics and Control and long-time prorector for education at the TU Ilmenau presented the research opportunities that the new experimental facility will open up, especially for experimental studies in the medium-voltage range for all components of a DC and mixed-voltage transmission system - for scientists at the TU Ilmenau, but also for research and industry partners as well as students at the university:

The experimental infrastructure installed with the help of the MMV project and various predecessor projects is unique in its interaction and offers the best conditions for already ongoing and upcoming research projects at the TU Ilmenau

The heart of the plant: the medium-voltage mixed-current test system MMP

The new test facility consists of several parts that can be used together or independently. At the opening colloquium, Prof. Michael Rock, head of the Group for Lightning and Surge Protection, demonstrated its capabilities by means of a recorded commissioning test: The largest and most powerful part of the facility, the so-called medium-voltage mixed-current test facility MMP, is capable of generating direct currents and surge currents of up to 100 kiloamperes with a maximum stored energy of two megajoules at up to 20 kilovolts. This allows it to be used for research on electromechanical, power electronics and hybrid DC switches, among other things, as well as for studies on high-voltage, high-current arcs with square-wave and surge pulses. Other parts of the facility include a Unidirectional DC Source as a special power electronic device with voltage range extended to medium voltage and a High-Voltage Modular Multilevel Converter as a power converter with internal storage option for AC-DC coupling and as a DC source for mixed current transmission. Prof. Petzoldt:

The modularity and interchangeability of these individual components up to the medium-voltage level is probably unique in the world and of great benefit both for basic and applied research and for industry-related research services.

The research infrastructure at ZET is already being used intensively, especially by start-up companies that have emerged from TU Ilmenau, and has produced important joint research results with the university and other research partners that have even led to joint patents. Prof. Petzoldt:

With this successful symbiosis and the excellent infrastructure at ZET, ThEFI on the one hand makes a significant contribution to industry-oriented research transfer and to securing skilled workers for regional industry, and on the other hand contributes significantly to the implementation of the energy transition and to solutions for closely related issues of electromobility.