Chapter 9: Q9-1MCQ (page 576)
For power-system fault studies, it is assumed that the system is operating under balanced steady-state conditions prior to the fault, and sequence networks are uncoupled before the fault occurs.
(a) True (b) False
Answer
The correct answer is (a) True.
Over 30 million students worldwide already upgrade their learning with Vaia!
All the tools & learning materials you need for study success - in one app.
Get started for free
Equipment ratings for the five-bus power system shown in Figure 7.15 are given as follows:
Generator
Generator
Transformer
Transformer
Each line:
Draw the zero-, positive-, and negative-sequence reactance diagrams using a 100 MVA,15 KV , base in the zone of generator G2. Neglect transformer phase shifts.
Faults at bus n in Problem 9.1 are of interest (the instructor selects ). Determine the Thevenin equivalent of each sequence network as viewed from the fault bus. Pre fault voltage is 1.0 per unit. Pre fault load currents and transformer phase shifts are neglected. (Hint: Use the conversion in Figure 2.33.)
Question: Equipment ratings for the four-bus power system shown in Figure 7.14 are given as follows:
Generator
Generator
Generator
Transformer
Transformer
Transformer
Each line:
The inductor connected to generator neutral has a reactance of . Draw the zero, positive, and negative-sequence reactance diagrams using a base in the zone of generator. Neglect transformer phase shifts.
The venin equivalent sequence networks looking into the faulted bus of a power system are given with , , and per unit. Compute the fault currents and voltages for the following faults occurring at the faulted bus:
(a) Balanced three-phase fault
(b) Single line-to-ground fault
(c) Line-line fault
(d) Double line-to-ground fault. Which is the worst fault from the viewpoint of the fault current?
Question: Faults at bus n in Problem 9.5 are of interest (the instructor selects or ). Determine the Thevenin equivalent of each sequence network as viewed from the fault bus. Prefault voltage is per unit. Prefault load currents and phase shifts are neglected.
What do you think about this solution?
We value your feedback to improve our textbook solutions.
