7/27/2019 R5410208 Reliability Engineering & Application to Power Systems

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Code: R5410208

B.Tech IV Year I Semester (R05) Supplementary Examinations December/January 2013/14

RELIABILITY ENGINEERING & APPLICATION TO POWER SYSTEMS

(Electrical & Electronics Engineering)(For 2006 Regular admitted students only)

Time: 3 hours Max. Marks: 80

Answer any FIVE questionsAll questions carry equal marks

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1 (a) Find the mean and variance of binomial distribution.

(b) Over a 10-minute period a counter records an average of 1.3 gamma particles per

millisecond coming from a radioactive substance. To a good approximation the

distribution of the count, x, of gamma particles during the next millisecond is Poisson.

Determine i) ii) The probability of one or more gamma particles and iii) The variance.

2 (a) Explain how network reliability/unreliability is evaluated for series/parallel

configurations.

(b) A system consists of four components in parallel. System success requires that at

least three of them must function. What is the probability of system success if the

component reliability is 0.8? What is the probability of system success if five

components are placed in parallel to perform the same function?

3 (a) Show that the expected value and standard deviation of an exponential failure density

function is same and is equal to the reciprocal of the constant hazard rate.

(b) Define the following terms and explain:

(i) MTTF (ii) MTTR (iii) MTBF (iv) Hazard rate function (v) Reliability function

(vi) Probability density function (vii) Cumulative probability distribution function.

4 (a) Explain what is meant by limiting state probability and how it is evaluated for discrete,

Markov chain model of a single component repairable system.

(b) Explain what is meant by STPM with a suitable example.

5 Find the cumulative probability and cumulative frequency of a three unit generating

system having capacities of two units of 25 MW each and one unit of 50 MW with a

failure rate 0.01 failures/day and repair rate of 0.49 repairs/day.

6 (a) Explain the concept of forced outage rate and equivalent forced outage rate.

(b) Explain LOLP method of assessing the generation inadequacy.

7 (a) Derive the expression for the weighted average repair rate for the transmission line due

to bad weather conditions.

(b) Consider two identical transmission lines with mean normal weather duration of 10

days and a mean severe period of 0.1 day. The line failure and repair rate are 0.002

per day and 0.05 per day and failure rate is 1 per day.

8 Explain basic and performance reliability indices of radial distribution system.

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R05