# Unsymmetrical Fault Analysis

## Bus Impedance Matrix Method for Analysis of Unsymmetrical Shunt Faults

Bus Impedance Matrix Method for Analysis of Unsymmetrical Shunt Faults: Bus Impedance Matrix Method of fault analysis, given for symmetrical faults  can be easily extended to the case of unsymmetrical faults. Consider for example an LG fault on the rth bus of a n-bus system. The connection of sequence networks to simulate the fault is …

## Open Conductor Faults

Open Conductor Faults: An open conductor faults is in series with the line. Line currents and series voltages between broken ends of the conductors are required to be determined. Figure 11.19 shows currents and voltages in an open conductor faults. The ends of the system on the sides of the fault are identified as F, …

## Double Line to Ground Fault

Double Line to Ground Fault (LLG): Figure 11.9 shows a Double Line to Ground Fault at F in a power system. The fault may in general have an impedance Zf as shown. The current and voltage (to ground) conditions at the fault are expressed as The symmetrical components of voltages are given by from which …

## Line to Line Fault

Line to Line Fault (LL): Figure 11.7 shows a Line to Line Fault at F in a power system on phases b and c through a fault impedance Zf. The phases can always be relabelled, such that the fault is on phases b and c. The currents and voltages at the fault can be expressed as …

## Single Line to Ground Fault

Single Line to Ground Fault: Figure 11.4 shows a Single Line to Ground Fault at F in a power system through a fault impedance Zf. The phases are so labelled that the fault occurs on phase a. At the fault point F, the currents out of the power system and the Single Line to Ground …

## Symmetrical Component Analysis of Unsymmetrical Faults

Symmetrical Component Analysis of Unsymmetrical Faults: Symmetrical Component Analysis of Unsymmetrical Faults – Consider a general power network shown in Fig. 11.1. It is assumed that a shunt type fault occurs at point F in the system, as a result of which currents Ia, Ib, Ic flow out of the system, and Va, Vb, Vc …

## Types of Unsymmetrical faults in Power System

Types of Unsymmetrical faults in Power System: There are two types of unsymmetrical faults in power system namely, Shunt Type Fault: Single Line to Ground Fault (LG) Line to Line Fault (LL) Double Line to Ground Fault (LLG) Series Type Fault: (i) Open conductor (one or two conductors open) fault. It was stated, that a three-phase …