Why LG fault is most severe in generator?

Hence, generators are grounded in the appropriate manner, where their SLG current is limited (usually below the generator nominal current). LLLG (line to line to line and ground)is the most severe fault for generators and will damaged maximum to generator with same current(fault) level of other types of faults.

Which fault is more severe in transmission line?

The results obtained show that symmetrical three phase fault is the most severe kind at the transmission lines, while for faults occurring very close to the generating station or synchronous generator, single line to ground fault is the most severe.

Which is more severe fault in power system?

Severity of faults: Among the given faults, LLLG or 3 phase faults are most severe. LG or line to ground fault is least severe. Line to line fault is more severe than line to ground fault while double line to ground fault is one level severe than LL.

Which fault is most severe fault?

Symmetrical Fault The L – L – L fault occurs rarely, but it is the most severe type of fault which involves the largest current. This large current is used for determining the rating of the circuit breaker.

Which faults are most severe faults?

Why single phase LG fault current can be more than a three phase fault current LLL )?

What is the only case that makes the single line-to-ground fault bigger than the 3-phase short circuit fault? The L-G fault current will exceed the 3Ø fault current whenever you are near the terminal of a D-Y transformer. Thus Z0 source is zero and the only Z0 contribution to the impedance is the transformer impedance.

Why is fault current so high?

Fault currents are caused by very low impedance short circuits. When there is a short circuit the resistance becomes very small, and that means the current becomes very large. If the resistance was zero, then the calculated fault current would go to infinity.