Question

In power-system fault studies, all nonrotating impedance loads are usually neglected.

(a) True

(b) False

Short answer

Therefore, the correct option is (a) True.

Step-by-step solution

Determine the assumptions to calculate sub transient fault current.

In order to calculate the sub transient fault current in a three-phase short circuit power system, the following assumptions are made:

1. Transformers are represented by leakage reactances. The shunt admittance, phase shifts and winding resistance are neglected.

2. The transmission lines are represented by series reactance by neglecting series resistance and shunt admittance.

3. Neglect all non-rotating loads.

4. Synchronous machines are represented by constant voltage source behind the subtransient reactance by neglecting armature resistance, saliency and saturation.

Determine the answer.

From assumptions 3, it is clear that the all non-rotating impedance loads are neglected.

Therefore, the correct option is (a) True.