REVISTA DYNA ENERGÍA

Key words:

Baja Tensión, Media Tensión, cortocircuito monofásico a tierra, falta serie, Low Voltage, Medium Voltage, fault to ground on the medium electrical network , one conductor open.

Article type:

COLABORACION/COLLABORATION DAMR

Section:

RESEARCH ARTICLES

ABSTRACT
This article highligts the fact that the power substation system neutral is grounded, should not be modified when the medium voltage (MV) electrical grid is connected to a power substation. That is, grounding of the wye on the MV side in the distribution transformers (wye / delta) of the distribution centers (DC´s) of the MV grid connected to the substation should be avoided.
Otherwise, series faults in the MV grid would will be very difficult to locate since in the dependent Low Voltage (LV) network. La absence of one phase in the MV would be masked by the distribution transformer with the neutral grounded, as the voltage values in each phase are kept within their normal operating values.
Furthermore, the coincidence of a serie and parallel fault in any of the powerlines of the MV grid powered by the same power substation would produce overvoltage in the LV.
If the only grounding neutral is located in the power substation, one open conductor in the MV grid, can be detected in the LV grid of each DC connected in the section of the line between the point of the one conductor open and the end of MV power line. This is because the voltage value measured in one phase is opposite to the sum of the voltage values of the other two phases

Keywords: Low Voltage, Medium Voltage, fault to ground on the medium electrical network , one conductor open (series fault).