Name of the College : Noorul Islam College of Engineering
University : Anna University
Degree : B.E
Department : Electrical & Electronic Engineering
Subject Code/Name : EE 1401 – Power System Operation & Control
Document Type : Question Bank
Website : niceindia.com
Download :https://www.pdfquestion.in/uploads/ni…ND_CONTROL.pdf
Power System Operation & Control Question Paper
Unit-I
(2 Marks) :
1. What is load curve? :
The curve drawn between the variations of load on the power station with reference to time is known as load curve. There are three types, Daily load curve, Monthly load curve, Yearly load curve
Related : Noorul Islam College of Engineering EE1302 Protection & Switchgear B.E Question Bank : www.pdfquestion.in/2993.html
2. What is daily load curve? :
The curve drawn between the variations of load with reference to various time period of day is known as daily load curve.
3. What is monthly load curve? :
It is obtained from daily load curve. Average value of the power at a month for a different time periods are calculated and plotted in the graph which is known as monthly load curve.
4. What is yearly load curve? :
It is obtained from monthly load curve which is used to find annual load factor.
5. What is connected load? :
It is the sum of continuous ratings of all the equipments connected to supply systems.
6. What is Maximum demand? :
It is the greatest demand of load on the power station during a given period.
7. What is Demand factor? :
It is the ratio of maximum demand to connected load.
Demand factor= (max demand)/ (connected load)
8. What is Average demand? :
The average of loads occurring on the power station in a given period (day or month or year) is known as average demand.
Daily avg demand = (no of units generated per day)/ (24 hours)
Monthly avg demand = (no of units generated in month)/ (no of hours in a month)
Yearly avg demand = (no of units generated in a year)/ (no of hours in a year)
9. What is Load factor? :
The ratio of average load to the maximum demand during a given period is known as load factor.
Load factor = (average load)/ (maximum demand)
10. What is Diversity factor? :
The ratio of the sum of individual maximum demand on power station is known as diversity factor.
Diversity factor = (sum of individual maximum demand)/(maximum demand).
11. What is Capacity factor? :
This is the ratio of actual energy produced to the maximum possible energy that could have been produced during a given period.
Capacity factor= (actual energy produced)/ (maximum energy that have been produced)
12. What is Plant use factor? :
It is the ratio of units generated to the product of plant capacity and the number of hours for which the plant was in operation. Units generated per annum= average load * hours in a year
13. What is Load duration curve? :
When the load elements of a load curve are arranged in the order of descending magnitudes the curve then obtained is called load duration curve.
Unit-II
1. What is the major control loops used in large generators? :
The major control loops used in large generators are 1.automatic voltage regulator (AVR) 2.automatic load frequency control (ALFC).
2. What is the use of secondary loop? :
A slower secondary loop maintains the fine adjustment of the frequency, and also by reset action maintains proper MW interchange with other pool members.
This loop is insensitive to rapid load and frequency changes but focuses instead on drift like changes which take place over periods of minutes.
3. What is the adv of AVR loop over ALFC? :
AVR loop is much faster than the ALFC loop and therefore there is a tendency, for the AVR dynamics to settle down before they can make themselves felt in the slower load frequency control channel.
4. What is the diff.between large and small signal analysis? :
Large signal analysis is used where voltage and power may undergo sudden changes of magnitude that may approach 100 percent of operating values. Usually this type of analysis leads to differential equations of non-linear type. Small signal anaysis is used when variable excursions are relatively small, typically at most a few percent of normal operating values.
5. What is the exciter? :
The exciter is the main component in AVR loop. It delivers the DC power to the generator field. It must have adequate power capacity and sufficient speed of response (rise time less than 0.1 sec).