Chapter 9: Q9-2MCQ (page 576)
The first step in power-system fault calculations is to develop sequence networks based on the single-line diagram of the system, and then reduce them to their Thévenin equivalents, as viewed from the fault location.
(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
Consider the system shown in Figure 9.18. (a) As viewed from the fault at F, determine the Thevenin equivalent of each sequence network. Neglect phase shifts. (b) Compute the fault currents for a balanced three phase fault at fault point F through three fault impedances per unit. Equipment data in per-unit on the same base are given as follows:
Synchronous generators:
Transformers:
Transmission lines:
Repeat Problem 9.24 for a bolted line-to-line fault.
Repeat Problem 9.21 for a bolted line-to-line fault.
Repeat Problem 9.43 for a bolted single line-to-ground fault at bus 1.
A single-line diagram of a four-bus system is shown in Figure 9.27. Equipment ratings and per-unit reactances are given as follows.
Machine and:
Transformers and:
On a base of 100 MVA and 345 kV in the zone of the transmission line, the series reactances of the transmission line areand . (a) Draw each of the sequence networks and determine the bus impedance matrix for each of them. (b) Assume the system to be operating at nominal system voltage without prefault currents when a bolted line-to-line fault occurs at bus 3. Compute the fault current, the line-to-line voltages at the faulted bus, and the line-to-line voltages at the terminals of machine 2. (c) Assume the system to be operating at nominal system voltage without prefault currents, when a bolted double line-to ground fault occurs at the terminals of machine 2. Compute the fault current and the line-to-line voltages at the faulted bus.
What do you think about this solution?
We value your feedback to improve our textbook solutions.
