Fundamental investigations on contactless, mobile measuring systems for lightning and switching impulse voltages according to standards.

• Applicants: Dr.-Ing. Johann Meisner; Professor Dr.-Ing. Peter Werle
• Subject Area: Electrical Energy Systems, Power Management, Power Electronics, Electrical Machines and Drives
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 537551470

In many countries, the increasing global demand for electrical energy can only be met by expanding energy transport capacities with ultrahigh-voltage (UHV) lines because of the long transmission distances involved. The components and equipment used for this are subject to operational loads (nominal load, load variations, switching operations) as well as external influences (lightning strikes, short circuits). Impulse voltages are therefore required in high-voltage tests to simulate the stresses caused by external and internal overvoltages, as well as for basic investigations of breakdown processes. The trend towards ever higher transmission voltages worldwide is making the development of impulse voltage dividers with correspondingly high rated voltages increasingly difficult and cost-intensive, so that alternatives are necessary. These could possibly be realized with the aid of modern, innovative measurement systems by using non-contact, feedback-free sensors to measure the electric field of the impulse voltages. A specially adapted, traceable field probe for these applications would be an elegant, transportable and at the same time efficient and cost-reduced solution. The aim of this research project is therefore to carry out investigations with various field sensor techniques in order to find measurement systems that can enable the development of an innovative, mobile system for the non-contact measurement of impulse voltages, whereby the mobile measurement system should differ significantly from conventional measurement systems with voltage dividers in terms of dimensions, costs and flexibility, and should also exhibit high linearity up into the ultra-high voltage range. This goal can only be achieved in cooperation between research institutions, so that the implementation of the project with the two institutes IfES of LUH and PTB as partners offers the advantage of being able to carry out the investigations with a larger selection of sensors and hardware. Especially since the measurements using field-based methods depend on the direct environment and the setup, it is absolutely necessary to be able to rely on the laboratories of at least two institutes in order to minimise any environmental influences. In addition, the two high-voltage laboratories of the institutes have a different architecture, so that differences between the laboratories exist, for example, in the geometry and the degree of shielding, so that these influences can also be investigated. Ultimately, a universally applicable system can only be developed on the basis of such comparative investigations, which would considerably expand the state of the art of pulse voltage measurement and could be used advantageously worldwide.

• DFG Programme: Research Grants