Research

TU Ilmenau
Electrical strength under composite voltage stresses

In addition to AC voltage, DC voltage is becoming increasingly important in energy transmission. High-voltage insulation systems in energy transmission networks will therefore be subjected to composite voltages (DC voltage and superimposed AC voltage) in the future. The frequency of the AC voltage ranges from the low frequency range (50 Hz) to the medium frequency range (up to 100 kHz). The influence of pre-discharges or the formation of charges on the surface of the insulating materials on the electrical strength under composite voltage stress is the subject of research.

Arc processes in dielectric fluids

A fundamental problem of high voltage direct current transmission is the coupling of the electrical equipment to energy networks. The reason for this is the lack of suitable HVDC circuit breakers. The research project evaluates a technology which should make it possible to interrupt high-voltage direct current in a technologically simple and safe way. The basic principle is based on an ultra-fast electromagnetic drive, which moves the switching contacts, between which a switching arc is formed, in a dielectric fluid. Of particular interest is the effect of the liquid, which essentially takes over the current interruption, through energy conversion of the electrical and magnetic energy stored in the network into chemical reaction energy.

TU Ilmenau
TU Ilmenau
FEM simulations of physical processes

The measurements in the laboratories are supported by FEM (Finite Element Method) simulations. The research unit uses licenses of numerous commercial software for the simulation of different physical processes. In addition to the calculation of electrostatic and electric flow fields, models exist that allow plasma-physical calculations of discharges and the charging of dielectric surfaces. Furthermore, flow processes in dielectric fluids and their thermal behavior are simulated.

Space charge measurement under mixed voltage stress

Under the effect of DC or composite voltages, space charges can form in the volume of insulating materials. These change the basic electric field and can thus lead to a more rapid failure of the insulating materials. To investigate the space charge, a PEA (pulsed electroacoustic method) measurement system is to be set up to measure the space charge distribution in dielectrics under composite voltage stress.

TU Ilmenau