The Switchgear Laboratory is one of the key laboratories of the Centre for Renewable Energy Research and Utilisation. It is used for research and development in the field of high current electrical devices. Such devices include, for example, circuit breakers and fuses for domestic installations, but also special coils that can be used, for example, in tokamaks.
A great speciality of this laboratory is the possibility of testing with DC currents up to 50 kA and also the possibility of carrying out long-term, so-called endurance tests for up to 3 s at currents up to 40 kA.
AC test parameters
AC 50/60 Hz – 200 ms:
- 150 kA / 250 V
- 100 kA / 500 V
- 60 kA / 750 V
- 40 kA / 1000 V
- 6 kA / 6 kV
AC 50/60 Hz – 3 s:
- 40 kA / 100 V
DC test parameters
- 50 kA / 1000 V – 200 ms (τ ≤ 30 ms)
- 4 kA / 4 kV – 200 ms
Continuously (low voltage)
- 5 kA AC
- 2,5 kA DC
Main activities
- Current path optimization
- Effect of contact materials on device function
- Measurement of the pressure field in the extinguishing chamber of switchgear
- Calculation of electromagnetic and temperature fields
- Switching arc physics - composition, thermodynamic and thermal properties of the switching arc plasma, radiative energy transport
Laboratory equipment
At the heart of the laboratory are three test sources:
- 16 MVA, 6 kW short-circuit generator.
- 2.5 MVA short-circuit transformer, which allows smaller tests to be carried out directly from the grid
- short-circuit battery
The short-circuit sources are followed by a set of high-voltage ballasts that allow the short-circuit current characteristics, especially the magnitude, to be adjusted. The loads are connected to a special short-circuit transformer which transforms the high voltage to a low voltage level. For high-current tests, the object under test is already directly connected to the output of the transformer.
The brain of the laboratory is the control room from which the individual experiments are controlled and evaluated. The laboratory is equipped with a number of special measuring instruments, including a high-speed camera that can record very fast events up to a million frames per second.
