Earthing of the neutral with limitation of the fault current
This technique consists of inserting an impedance between neutral and earth.
Electrical impedance measures the opposition of an electrical circuit to the passage of a sinusoidal alternating current. An impedance will therefore play a role in retaining or obstructing the current.
The concept of impedance makes it possible to apply the formulas used in continuous mode to sinusoidal conditions, while integrating the effect of capacitive and inductive elements.
There are 3 types of impedances:
- Arc extinguishing coil (Petersen coil)