Copyright © 2014 mat - Maschinen- und Anlagentechnik Dr. Becker GmbH - Last Update: 30.07.2019
"Neutral point treatment plant in Earthquake-resistant design"
For installation in an earthquake zone 3 a neutral point treatment plant was calculated
built and delivered.
Calculations have shown that the system has to be
designed for a step response of 5.1 m / sec ².
This requirement could only be solved by use of more
specifically arranged steel wire springs.
"A development that sets new standards in terms of relieving the ground fault
location in medium voltage network is. "
Ground fault in medium voltage networks
Relief of fault location by phase grounding
Earth Fault Detection
The phase grounding is useful applicated in inductive grounded medium voltage networks by arc
suppression coils. The use in isolated systems is also possible. During a single-pole ground fault
due to the earth capacitance of the cables or overhead lines a capacitive charging current is flowing
through the fault place.
Through the use of arc suppression coils, which is connected in the neutral point of the power
transformer or is switched to the neutral point of a grounding transformer, inductive compensation
current (180 ° phase) flows in the event of a ground fault into the fault place.
Through accurate compensation by means of an adjustable plunger core arc suppression coil and
a qualified compensation controller, the capacitive charging current can be brought to zero (in case
of resonance tuning). At the fault location only the “Watt residual current” remains, which however in
large cable networks can have quite a couple of amps. In case of over- or under-compensation
(detuning), an additional reactive current flows over the fault location according to the detuning degree.
A new development is the phase
earthing for insulated medium voltage networks, earth fault detection encluded. Due to possibly very
high residual currents up to 150 A, a fourth circuit breaker is involved.
+49 4532 2021-01
+49 4532 2021-21