Electric machinery fundamentals
5th Edition
ISBN: 9780073529547
Author: Chapman, Stephen J.
Publisher: MCGRAW-HILL HIGHER EDUCATION
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 2, Problem 2.20P
A 50-kVA, 20,000/480-V, 60-Hz, single-phase distribution transformer is tested with the following results:
- Find the per-unit equivalent circuit for this transformer at 60 Hz.
- What is the efficiency of the transformer at rated conditions and unity power factor? What is the voltage regulation at those conditions?
- What would the rating of this transformer be if it were operated on a 50-Hz power system?
- Sketch the equivalent circuit of this transformer referred to the primary side if it is operating at 50 Hz.
- What is the efficiency of the transformer at rated conditions on a 50-Hz power system, with unity power factor? What is the voltage regulation at those conditions?
- How does the efficiency of a transformer at rated conditions and 60 Hz compare to the same physical device running at 50 Hz?
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
please show full working. I've included the solution
can you please show working and steps. The answer is 8kohms.
PSD
A certain signal f(t) has the following PSD (assume 12 load):
| Sƒ(w) = π[e¯\w\ + 8(w − 2) + +8(w + 2)]
(a) What is the mean power in the bandwidth w≤ 1 rad/sec?
(b) What is the mean power in the bandwidth 0.99 to 1.01 rad/sec?
(c) What is the mean power in the bandwidth 1.99 to 2.01 rad/sec?
(d) What is the total mean power in (t)?
Pav=
+
2T
SfLw) dw
- SALW)
Chapter 2 Solutions
Electric machinery fundamentals
Ch. 2 - Is the turns ratio of a transformer the same as...Ch. 2 - Why does the magnetization current impose an upper...Ch. 2 - What components compose the excitation current of...Ch. 2 - What is the leakage flux in a transformer? Why is...Ch. 2 - List and describe the types of losses that occur...Ch. 2 - Why does the power factor of a load affect the...Ch. 2 - Why does the short-circuit test essentially show...Ch. 2 - Why does the open-circuit test essentially show...Ch. 2 - How does the per-unit system of measurement...Ch. 2 - Why can autotransformers handle more power than...
Ch. 2 - What are transformer taps? Why are they used?Ch. 2 - What are the problems associated with the Y—Y...Ch. 2 - What is a TCUL transformer?Ch. 2 - How can three-phase transformation be accomplished...Ch. 2 - Prob. 2.15QCh. 2 - Can a 60-Hz transformer be operated on a 50-Hz...Ch. 2 - What happens to a transformer when it is first...Ch. 2 - What is a potential transform? How is it used?Ch. 2 - What is a current transformer? How is it used?Ch. 2 - A distribution transformer is rated at 18 kVA,...Ch. 2 - Why does one hear a hum when standing near a large...Ch. 2 - A 100-kVA, 8000/277-V distribution transformer has...Ch. 2 - A single-phase power system is shown in Figure...Ch. 2 - Consider a simple power system consisting of an...Ch. 2 - The secondary winding of a real transformer has a...Ch. 2 - When travelers from the USA and Canada visit...Ch. 2 - A 1000-VA, 230/115-V transformer has been tested...Ch. 2 - A 30-kVA, 8000/230-V distribution transformer has...Ch. 2 - A 150-MVA, 15/200-kV, single-phase power...Ch. 2 - A 5000-kVA, 230/13.8-kV, single-phase power...Ch. 2 - A three-phase transformer bank is to handle 500...Ch. 2 - A 100-MVA, 230/115-kV, Y three-phase power...Ch. 2 - Three 20-kVA, 24,000/277-V distribution...Ch. 2 - A 14,000/480-V, three-phase, Y-connected...Ch. 2 - A 13.8-kV, single-phase generator supplies power...Ch. 2 - An autotransformer is used to connect a 12.6-kV...Ch. 2 - Prove the following statement: If a transformer...Ch. 2 - A 10-kVA, 480/120-V conventional transformer is to...Ch. 2 - A 10-kVA, 480/120-V conventional transformer is to...Ch. 2 - Two phases of a 14.4-kV, three-phase distribution...Ch. 2 - A 50-kVA, 20,000/480-V, 60-Hz, single-phase...Ch. 2 - Prove that the three-phase system of voltages on...Ch. 2 - Prove that the three-phase system of voltages on...Ch. 2 - A single-phase, 10-kVA, 480/120-V transformer is...Ch. 2 - Figure P2-4 shows a one-line diagram of a power...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, electrical-engineering and related others by exploring similar questions and additional content below.Similar questions
- An AM modulation waveform signal:- p(t)=(8+4 cos 1000πt + 4 cos 2000πt) cos 10000nt (a) Sketch the amplitude spectrum of p(t). (b) Find total power, sideband power and power efficiency. (c) Find the average power containing of each sideband.arrow_forwardCan you rewrite the solution because it is unclear? AM (+) = 8(1+ 0.5 cos 1000kt +0.5 ros 2000ks) = cos 10000 πt. 8 cos wat + 4 cos wit + 4 cos Wat coswet. -Jet jooort J11000 t = 4 e jqooort jgoort +4e + e +e j 12000rt. 12000 kt + e +e jooxt igoo t te (w) = 8ES(W- 100007) + 8IS (W-10000) USBarrow_forwardCan you rewrite the solution because it is unclear? AM (+) = 8(1+0.5 cos 1000kt +0.5 ros 2000 thts) = cos 10000 πt. 8 cos wat + 4 cos wit + 4 cos Wat coswet. J4000 t j11000rt $14+) = 45 jqooort +4e + e + e j 12000rt. 12000 kt + e +e +e Le jsoort -; goon t te +e Dcw> = 885(W- 100007) + 8 IS (W-10000) - USBarrow_forward
- Can you rewrite the solution because it is unclear? Q2 AM ①(+) = 8 (1+0.5 cos 1000πt +0.5 ros 2000kt) $4+) = 45 = *cos 10000 πt. 8 cos wat + 4 cosat + 4 cos Wat coswet. j1000016 +4e -j10000πt j11000Rt j gooort -j 9000 πt + e +e j sooort te +e J11000 t + e te j 12000rt. -J12000 kt + с = 8th S(W- 100007) + 8 IS (W-10000) <&(w) = USB -5-5 -4-5-4 b) Pc 2² = 64 PSB = 42 + 4 2 Pt Pc+ PSB = y = Pe c) Puss = PLSB = = 32 4² = 8 w 32+ 8 = × 100% = 140 (1)³×2×2 31 = 20% x 2 = 3w 302 USB 4.5 5 5.6 6 ms Ac = 4 mi = 0.5 mz Ac = 4 ५ M2 = =0.5arrow_forwardA. Draw the waveform for the following binary sequence using Bipolar RZ, Bipolar NRZ, and Manchester code. Data sequence= (00110100) B. In a binary PCM system, the output signal-to-quantization ratio is to be hold to a minimum of 50 dB. If the message is a single tone with fm-5 kHz. Determine: 1) The number of required levels, and the corresponding output signal-to-quantizing noise ratio. 2) Minimum required system bandwidth.arrow_forwardFind Io using Mesh analysisarrow_forward
- FM station of 100 MHz carrier frequency modulated by a 20 kHz sinusoid with an amplitude of 10 volt, so that the peak frequency deviation is 25 kHz determine: 1) The BW of the FM signal. 2) The approximated BW if the modulating signal amplitude is increased to 50 volt. 3) The approximated BW if the modulating signal frequency is increased by 70%. 4) The amplitude of the modulating signal if the BW is 65 kHz.arrow_forwardAn FDM is used to multiplex two groups of signals using AM-SSB, the first group contains 25 speech signals, each has maximum frequency of 4 kHz, the second group contains 15 music signals, each has maximum frequency of 10 kHz. A guard bandwidth of 500 Hz is used bety each two signals and before the first one. 1. Find the BWmultiplexing 2. Find the BWtransmission if the multiplexing signal is modulated using AM-DSB-LC.arrow_forwardAn FM signal with 75 kHz deviation, has an input signal-to-noise ratio of 18 dB, with a modulating frequency of 15 kHz. 1) Find SNRO at demodulator o/p. 2) Find SNRO at demodulator o/p if AM is used with m=0.3. 3) Compare the performance in case 1) and 2).. Hint: for single tone AM-DSB-LC, SNR₁ = (2m²) (4)arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Power System Analysis and Design (MindTap Course ...Electrical EngineeringISBN:9781305632134Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. SarmaPublisher:Cengage Learning
Electricity for Refrigeration, Heating, and Air C...Mechanical EngineeringISBN:9781337399128Author:Russell E. SmithPublisher:Cengage Learning
Power System Analysis and Design (MindTap Course ...
Electrical Engineering
ISBN:9781305632134
Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma
Publisher:Cengage Learning
Electricity for Refrigeration, Heating, and Air C...
Mechanical Engineering
ISBN:9781337399128
Author:Russell E. Smith
Publisher:Cengage Learning
TRANSFORMERS - What They Are, How They Work, How Electricians Size Them; Author: Electrician U;https://www.youtube.com/watch?v=tXPy4OE7ApE;License: Standard Youtube License