The failure of power transformers is assumed to follow a Poisson probability distribution. Suppose on the average, a transformer fails once every 10 years, what is the probability that it will not fail in the next 12 months? once in the next 24 months?One thousand new OCRs are put in service. They have a constant failure rate 0f 0.05 per year.How many units of the original 1000 will still be in service after 5 years?How many of the original will fail in Year 5?

As per the guidelines, the first question has been solved in the following section.

The failure of power transformers is assumed to follow a Poisson probability distribution. Suppose on the average, a transformer fails once every 10 years, what is the probability that it will not fail in the next 12 months? once in the next 24 months?

The failure of power transformers is assumed to follow a Poisson probability distribution. Suppose on the average, a transformer fails once every 10 years, what is the probability that it will not fail in the next 12 months? once in the next 24 months?

Power System Analysis and Design (MindTap Course List)

6th Edition

ISBN:9781305632134

Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Publisher:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Chapter3: Power Transformers

Section: Chapter Questions

Problem 3.37P: Three single-phase two-winding transformers, each rated 25MVA,54.2/5.42kV, are connected to form a...

See similar textbooks

Related questions

Q: During short-circuit test of a transformer, the core loss of a transformer is negligible. Select…

A: Need to find true false

Q: B: List the location and equation of Economical Number of Transformers operation of distribution…

A: Distribution system: Distribution system is the essential part of power system. It is used to…

Q: Q14 An ideal transformer is rated at 2700/12O 9.6KVA, and has 5o turns on the seund side. Caleulate…

A: Transformer is static device which work on Faraday's Law of electromagnetic induction. The secondary…

Q: A building has a 35 kW transformer that is connected all the time. A local electrical contractor…

A: Given P = 35 Kw Core loss = 4% Electrical costs = 9 ζ/Kwh Average building use = 8 h/month Total…

Q: A 200 – MVA, 15/200 kV single-phase power transformer has a per – unit resistance of 1.2 percent…

A: Part (1): Consider the base voltage to be 15 V and the base MVA to be 200 MVA. Since the base…

Q: A12 Efficiency of DC machine is high as compared to the transformer. (TRUE/FALSE)

A: In all electrical machines transformer will have higher efficiency. Because there are no rotational…

Q: Using various types of transformers, give 10 impacts to the end-users per type of transformer in…

A: Transformer: Transformer is the static device that either step-up or step-down the voltage. It works…

Q: where a dashpot mechanism is employed in a constatant-current transformer, it is used as a…

Q: If the open circuit voltage is 227V and the full load voltage is 207V, then the percentage…

Q: Assume that there are two primary feeders supplied by a transformer T1. One of the feeders supplies…

A: We know, Diversity Factor=Maximum noncoincident demandmaximum diversified demandThe maximum…

Q: The open circuit test in a 100 kVA, 2000/200 V, 50 Hz, single phase transformer gives 200 V, 90 A, 5…

Q: Important Note Up to this point, an ideal transformer has been described by a ratio given either as…

Q: What are the advantages of the star/star connected transformer? And why it is preferred by many…

A: advantages of the star/star connected transformer?

Q: Using the parameters from the Typical Transformer Values Sheet for a 12.4kV/600V, 100 kVA…

Q: 1. The RMS value of induced emf in the primary N1 winding is E1 =; E2 = 2. In ideal transformer on…

Q: Let a 5kVA, 400/200 V transformer be approximately represented by a 2Ω reactance referred to the…

Q: (a) The size of transformer is usually defined in term of apparent power (VA) while the size of…

Q: (a) A 5 MVA 230/10.5-kV single-phase power transformer has a per-unit resistance of 1.5% and a…

Q: During short-circuit test of a transformer, the core loss of a transformer is negligible. Select…

A: In this answer we will discuss whether the core loss of a transformer is less / not when conducting…

Q: Data from short-circuit and open-circuit tests of a 25-kVA, 6900-230 V, 60 Hz transformer are given…

Q: The diagram for a single phase 60 MVA transformer is given below. Convert it to a Step-down…

A: In this question , we will convert single phase transformer into step down auto transformer..

Q: (a) As an Engineer you have been contracted by a power distribution company to investigate the…

A: In the case of the urban area, there is both overheating and overloading. Here the load is more than…

Q: (b) A 50-kVA, 2600/1300-V, single-phase transformer has a core loss of 780 W. The transformer has a…

Q: Consider a single phase transformer of rating 150 KVA, 3600/360, 50 Hz. Let the series resistance…

A: Formula to calculate voltage required to produce rated current at short circuit is: VSC=V1×ZPUwhere…

Q: The per-unit system calculations method allows to: Select one: O a. eliminate the need for explicit…

A: Most of human energy requirement is meet by generating electrical energy. Once electrical energy is…

Q: The efficiency of a 400 kVA, 1-phase transformer is 95 % when delivering full load at 0.8 power…

Q: 9. While conducting short short circuit test in a transformer, which side is short circuited?

A: We are authorized to answer one question at a time, since you have not mentioned which question you…

Q: Question # 2: A 2000/400 V, 100 kVA, 60 Hz step-down single-phase transformer has a primary and…

Q: What are the factors affecting the dielectric strength of Transformer oil?? Explain the maintenance…

A: Given Questions on transformer oil. Please find the answers below.

Q: Quiz2: We wish to connect a 6 kVA, 120/240 V transformer as an autotransformer to a 120 V source to…

Q: A two-winding transformer rated at 100 kVA, is connected as an autotransformer to provide 10kV from…

A: We are authorized to answer one question at a time, since you have not mentioned which question you…

Q: 1. A quantity is expressed in per unit if it is divided by a chosen base quantity having the same…

A: Given, Base power= 10 KW Base Voltage (HV)=2400 V Base voltage (LV)=240 V Base current (LV)=Base…

Q: A 40 kVA, 6,600/250V, 50 Hz transformer is having total reactance of 35 ohms when referred to…

A: Given Data: Rating = 40 kVA R1 = 10 ohm R2 = 0.2 ohm E1 = 6600 V E2 = 250 V

Q: A transformer of 100MVA, 60Hz, 138/69 kV, works as step down, has the following parameters: r1 =…

Q: A 400-turns auto transformer, operating in the step-down mode with 25 percent tap supplies a 4.8…

Q: A single-phase two-winding transformer rated 90 MVA, be connected as an autotransformer rated 80/200…

Q: Here is a single phase transformer, 15 kVA, 15000/380 V, 50 Hz has Ze-0.02+j0.05 perunit, R. 50…

Q: A 50-kVA 13.8-kV/208-V (rms, line-line) ∆−Ythree-phase distribution transformer has a per-unit…

A: Dear student as per our guidelines we are supposed to solve only one question in which it should…

Q: Transformers are widely used for industrial and residential applications. In long distance…

A: The transformer has a primary and a secondary side. It converts electrical power to electrical power…

Q: 2.2. The figure below shows a radial transmission system with a generator having a per-unit voltage…

A: Since we only answer up to 3 sub-parts, we’ll answer the first 3. Please resubmit the question and…

Q: A single-phase, 10-kVA, 480/120-V transformer is to be used as an autotransformer tying a 600-V…

A: The base impedance referred to the primary side is determined as: Zb=(480 V)210 KvA=23.04 ohmFor…

Q: A 35 kVA, single-phase transformer is tested on both open-circuit and short-circuit condition,…

A: Efficiency = output power/input power. Cupper loss is varies with load and iron loss is constant at…

Q: As an Engineer you have been contracted by a power distribution company to investigate the causes of…

A: When the load on the transformer is increased than its maximum capability then it is called…

Q: A 20-KVA, 20,000/480-V, 60-Hz distribution transformer is tested with the following results:…

A: Given Parameters of a distribution transformer. We need to sketch the per equivalent circuit.…

Q: A 15-kVA 8000/230-V distribution transformer has an impedance referred to the primary of 80 + j3002.…

A: Part (a): The turn ratio of the transformer is determined as: a=8000 V230 V=34.78 The load impedance…

Q: A 100,000-kVA 230/115-kV ∆-∆ three-phase power transformer has a per-unit resistance of 0.02 pu and…

A: Given Data Rating 100,000-kVA 230/115-kV Type : ∆-∆ three-phase per-unit resistance = 0.02 pu…

Q: A 240-kVA, 480/4800-V, step-up transformer has the following constants: Rs = 2.5 Ω, Xs = j5.75 Ω, Rp…

A: Given step up Transformer with240 KVA, 480/4800 vRs=2.5 Ω,Xs=j5.75 ΩRp=25 mΩ,Xp=j57.5 ΩThe core…

Q: 302 j722 םרהj 302 The label values of the single-phase transformer whose electrical equivalent…

A: Given: A 20 KVA, 15400 V/240 V, 50 Hz, single-phase transformer has the following equivalent…

Concept explainers

Maximum power transfer theorem

A resistive load will consume maximum power from a network when the load resistance is equal to the resistance of the network as viewed from the open-circuit terminals, with all energy sources removed leaving only the internal resistances. Physicist Moritz von Jacobi introduced the maximum power transfer theorem in 1940. Therefore, this theorem is also known as Jacobi's law.

Question

The failure of power transformers is assumed to follow a Poisson probability distribution. Suppose on the average, a transformer fails once every 10 years, what is the probability that it will not fail in the next 12 months? once in the next 24 months?
One thousand new OCRs are put in service. They have a constant failure rate 0f 0.05 per year.

How many units of the original 1000 will still be in service after 5 years?
How many of the original will fail in Year 5?

Expert Solution

This question has been solved!

Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.

SEE SOLUTION Check out a sample Q&A here

Step 1

VIEW

Step 2

VIEW

Step 3

VIEW

Step by step

Solved in 3 steps

SEE SOLUTION Check out a sample Q&A here

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 ideal transformer has no real or reactive power loss. (a) True (b) False
Three single-phase, two-winding transformers, each rated 450MVA,20kV/288.7kV, with leakage reactance Xeq=0.10perunit, are connected to form a three-phase bank. The high-voltage windings are connected in Y with a solidly grounded neutral. Draw the per-unit equivalent circuit if the low-voltage windings are connected (a) in with American standard phase shift or (b) in Y with an open neutral. Use the transformer ratings as base quantities. Winding resistances and exciting current are neglected.
Consider Figure 3.4. For an ideal phase-shifting transformer, the imda nce is unchanged when it is referred from one side to the other. (a) True (b) False
A bank of three single-phase transformers, each rated 30MVA,38.1/3.81kV, are connected in Y- with a balanced load of three 1, Y-connected resistors. Choosing a base of 90MVA,66kV for the high-voltage side of the three-phase transformer. spify the base for the low-voltage side. Compute the per-unit resistance of the load on the base for the low-voltage side. Also, determine the load resistance in ohms referred to the high-voltage side and the per-unit value on the chosen base.
The ideal transformer windings are eliminated from the per-unit equivalent circuit of a transformer. (a) True (b) False
Consider a bank of this single-phase two-winding transformers whose high-voltage terminals are connected to a three-phase, 13.8-kV feeder. The low-voltage terminals are connected to a three-phase substation load rated 2.0 MVA and 2.5 kV. Determine the required voltage, current, and MVA ratings of both windings of each transformer, when the high-voltage/low- voltage windings are connected (a) Y-, (b) -Y, (c) Y-Y, and (d) -.
Three single-phase two-winding transformers, each rated 25MVA,54.2/5.42kV, are connected to form a three-phase Y- bank with a balanced Y-connected resistive load of 0.6 per phase on the low-voltage side. By choosing a base of 75 MVA (three phase) and 94 kV (line-to-line) for the high-voltage side of the transformer bank, specify the base quantities for the low-voltage side. Determine the per-unit resistance of the load on the base for the low-voltage side. Then determine the load resistance RL in ohms referred to the high-voltage side and the per-unit value of this load resistance on the chosen base.
For a short-circuit test on a 2-winding transformer, with one winding shorted, can you apply the rated voltage on the other winding? (a) Yes (b) No
The symbol shown is a(n) a. iron core transformer. b. auto transformer. c. current transformer. d. air core transformer.
Two 100-kW, single-phase transformers are connected in parallel both on the primary and secondary. One transformer has an ohmic drop of 0.5% at full-load and an inductive drop of 8% at full-load current. The other has an ohmic drop of 0.75% and an inductive drop of 2%. Show how they will share a load of 180 kW at 0.9 p.f.
7. The primary of a single-phase transformer takes 1 A at power factor of 0.4 when connected to a 240-V, 50-Hz supply and the secondary is on open circuit. The number of turns on the primary is twice that on the secondary. A load taking 50 A at a lagging power factor of 0.8 is now connected across the secondary. What is now the value of the primary current ? transformer.) (Neglect the voltage drops in the
A power transformer with standard insulation class of 69 kv will withstand an rms test voltage of A. 140 kv. B. 350 kv. C. 69kv. D. 440 kv.