Resistant fault detection
Plan de protection des réseaux de distribution publique à moyenne tension

Resistive and highly resistive faults are always of the stable type, even on networks with compensated neutral, which means that symmetrical components (Fortescue's theorem) can be used for calculations. Earlier, we identified the limits of amperometric and wattmetric outgoing protection in the presence of earth faults. For resistive and very resistive faults that these protections are unable to detect, centralized protections have long been used, using either amperometric or voltmetric criteria, depending on the neutral system.

When the MV neutral is of the low-impedance type, we generally measure the current flowing in the MV neutral, as the presence of a significant current indicates the presence of a single-phase...