EE2028 POWER QUALITY
UNIT – 1: INTRODUCTION TO POWER QUALITY
1. What are the major power quality issues and explain them.
2. Explain power quality and explain the reasons for increased concern in power quality.
3. Explain the various types of power quality disturbances.
4. Explain the impacts of power quality.
5. Discuss in detail about sags and swells.
6. Discuss in detail about transients.
7. Define waveform distortion and explain the waveform distortion categories.
8. Explain total harmonic distortion and total demand distortion.
9. Discuss about the CBEMA curves and explain the events described in the curve.
10. With a waveform sketch , explain the terms.
• Voltage sag
• Voltage interruption
• Voltage swells
• Sag with harmonics.
UNIT – 2: VOLTAGE SAGS AND INTERRUPTIONS
1. Discuss the sources of sags and interruption.
2. Discuss in detail about the sag performance evaluation indices.
3. Explain the sag performance evaluation methods.
4. Explain the various causes and effects of voltage sags.
5. What are the different voltage sag mitigation techniques? Explain in detail.
6. Explain the principle of DVR operation used for sag mitigation.
7. Discuss in detail about the active series compensator.
8. Explain the solid state transfer switch with the transfer operation.
9. Explain the system adapted to estimate the severity of the sag occurred due to various sources.
10. Mention the standards associated with the voltage sag.
UNIT – 3: OVERVOLTAGE TRANSIENTS
1.What are transient overvoltages? Explain the different types of transient overvoltages.
2.Draw the CBEMA curve for transient overvoltages and explain
3.What are the different sources of transient overvoltages? Discuss the Capacitor switching transient.
4.What are the important concerns for capacitor bank switching?
5.Define lightning? Discuss in detail about the overvoltages due to lightning and the problems associated with it.
6.Explain in detail the mechanism of lightning.
7.Draw the standardized waveform of the lightning induced voltage. Discuss about the wave shape of the lightning current.
8.Explain the phenomena of ferroresonance.
9.Explain the problems associated with ferroresonance.
10.What is the need for protection against overvoltages? What are the basic principles of over voltages protection of load equipments?
11.Explain in detail about various methods to mitigate voltage swells
12.Explain in detail about the surge arrestors and surge suppressors.
13.What are the advantages of surge arrestors? Discuss about the application module.
14.Explain the following:
(a) Low pass filters (b) Power conditioners (c) Surge filters
UNIT – 4 HARMONICS
1. Explain briefly about fundamentals of harmonics generation and wave form distortion.
2. Explain in detail about classification of linear loads and non linear loads used in harmonic studies.
3. Explain the concept of harmonic phenomena under the presence of harmonic producing loads.
4. Explain for the following terms (i) Harmonic distortion (ii) Current distortion (iii) Voltage distortion
5. What are the two important harmonic indices used in power system? Explain about it briefly.
6. Give the power definitions under non sinusoidal conditions. Explain briefly about it.
7. Differentiate between true power factor and displacement power factor under harmonic
studies.
8. Explain briefly about various harmonic characterization on power systems.
9. Explain briefly about the phenomena of how current distortion affects the voltage distortion under the presence of harmonics.
10. What are the general causes of harmonics in power system?
11. What are the various causes of harmonics in distribution power system?
12. What are the effect of facility and site under the presence of harmonics?
13. List the various effects of equipments due to harmonics. Explain briefly.
14. Explain the harmonic effects on power system equipments briefly.
15. What are the various classifications of harmonic sources and explain briefly about it?
UNIT – 5 POWER QUALITY MONITORING
1. Bring out the significance of power quality monitoring. What are the important
power quality monitoring objectives?
2. Explain proactive monitoring.
3. Discuss in detail about the selection of power quality monitoring sites.
4. Explain the steps involved in power quality monitoring. What are the information from monitoring site surveys?
5. Bring out the important characteristics of power quality variation.
6. Write short notes on power quality measurement system. What are the characteristic of power quality measurement equipments?
7. Write notes on power line disturbance analyzer.
8. What are the various instruments used for power quality measurements? What are the factors to
be considered when selecting the instruments?
9. Discuss in detail about the instruments used for analyzing non sinusoidal voltage and currents.
10. Explain Harmonic/Spectrum analyzer.
11. Define voltage flicker. Discuss some of the flicker sources. Write notes on common methods for
mitigation of flicker.
12. Discuss in detail about the flicker meter.
13. Explain the modem power quality monitors.
14. Bring out the applications of expert system for power quality monitoring.
15. Draw and explain the functional structure of expert systems.
16. Draw the block diagram of advanced power quality monitoring systems. Explain it.