Faults

In which type of faults given below all the 3 components \(I_{a0}\) , \(I_{a1}\) and \(I_{a2}\) are equal?

For a single line to ground fault the zero sequence current is given by j3.0pu. The current carried by the neutral during the fault is

For a single line to ground fault the zero sequence current is given by j3.0 pu. The current carried by the neutral during the fault is

Fault level means

A 150-MVA, 13.8-KV, Y-connected, 3ɸ, 60-HZ alternator is operating at rated voltage and at no-load when a three-phase faults occurs at its terminals. If the substransient reactance of the alternator is j0.2 pu, calculate the current the instant fault occurs.

The per unit value of a 2-ohm resistor at 100 MVA base and 10 KV base voltage is

The reactance of a generator designated X” is given as 0.25 per unit based on the generator’s nameplate rating of 18 kV, 500 MVA. The base for calculations is 20 kV, 100 MVA. Find X” on the new base.

The line currents in amperes in phases a, b and c respectively are 500 + j150,100 – j600, and -300 + j600. Determine the zero sequence component of phase a current

There is no zero sequence component of the fault current for

The per unit impedance of a circuit element is 0.30. If the base kV and base MVA are halved, then the new value of the per unit impedance of the circuit element will be

Fault level means

When a line to ground fault occurs, the current in a faulted phase is 300 A. What is the zero sequence current in this case?

In a circuit breaker, the time duration from the instant of the fault to the extinction of the arc is known as

What is the device function number for overcurrent relay?

A balance delta connected load draws 100 A line current form a balanced 3- phase supply. Determine the zero sequence components of the currents.

What is the IEEE device function number 50?

The per unit value of 2 ohm resistor at 100 MVA base and 10 KV base voltage is

For a single line to ground fault, the zero sequence current is given by j3 pu. The current carried by the neutral during the fault is

The per-unit reactances of a synchronous generator are \(X_d = 1.1\), \(X_d' = 0.24\) and \(X_d'' = 0.15\). The generator is operating without load at 5 percent above rated voltage when a three-phase short circuit occurs at its terminals. What is the per unit subtransient fault current?

In a short circuit study, the positive, negative and zero sequence impedances are 0.25 pu, 0.25 pu and 0.3 pu, respectively. The base MVA is 100. Determine the fault current for a three-phase fault at the 115 kV level.