Electric machinery fundamentals
5th Edition
ISBN: 9780073529547
Author: Chapman, Stephen J.
Publisher: MCGRAW-HILL HIGHER EDUCATION
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Textbook Question
Chapter 2, Problem 2.13P
A 14,000/480-V, three-phase,
- If this bank delivers a rated load at 0.8 PF lagging and rated voltage, what is the line-to-line voltage on the primary of the transformer bank?
- What is the voltage regulation under these conditions?
- Assume that the primary phase voltage of this transformer is a constant 8314 V, and plot the secondary voltage as a function of load current for currents from no-load to full-load. Repeat this process for power factors of 0.8 lagging, 1.0, and 0.8 leading.
- Plot the voltage regulation of this transformer as a function of load current for currents from no-load to full-load. Repeat this process for power factors of 0.8 lagging, 1.0, and 0.8 leading.
- Sketch the per-unit equivalent circuit of this transformer.
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The rated voltages of a single-phase transformer are 2000 V and 200 V in its
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A three-phase transformer bank is connected
wye–delta. The primary voltage is 12,470 V, and the secondary voltage
is 480 V. The total capacity of the transformer bank is 450 kVA. One of the three
transformers that form the three-phase bank develops a shorted primary winding and
becomes unusable. A suggestion is made to reconnect the bank for operation as an
open-delta. Can the two remaining transformers be connected open-delta? Explain
your answer as to why they can or why they cannot be connected as an open-delta.
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2) 9.2Three - 25 KVA single-phase transformers are connected in delta – delta. One of the transformers has been defected. What is the maximum real power that the transformer bank can deliver at a power factor of 0.8?
Chapter 2 Solutions
Electric machinery fundamentals
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