Question

Define a 3 phase short circuit and a line to ground faults in a PV system. How it affect the load and how it can be eliminated. Also make analysis on how it affect active and reactive power and the efficiency of the system.

Answer 1

These are very harsh faults and arise uncommonly in the power systems. These are also called as balanced faults and are of two types namely line to line to line (L-L-L) and line to line to line to ground (L-L-L-G)

The objectionable situation of current flowing through the grounding conductor is called as a line to ground fault in PV system. The reason for this unwanted current flow is an unintentional electrical connection between a current-carrying conductor in the PV system and the equipment grounding conductor (EGC).

The particular purpose of a ground-fault protection device (GFPD) as an element of a PV power system is used to reduce the hazard of fire-related with a ground fault. "If the ground fault is a short-circuit," the NJATC’s Photovoltaic Systems notes, "the fault current can be very high. In addition to being a protection risk, this generates a significant fire vulnerability as exposed metal is heated by the current flow."