3 0 0 3
To study the various issues affecting power quality, their production, monitoring and suppression.
i. To study the production of voltages sags, overvoltages and harmonics and methods
ii. To study various methods of power quality monitoring.
UNIT I INTRODUCTION TO POWER QUALITY 9
Terms and definitions: Overloading - under voltage - over voltage. Concepts of transients - short
duration variations such as interruption - long duration variation such as sustained interruption. Sags
and swells - voltage sag - voltage swell - voltage imbalance - voltage fluctuation - power frequency
variations. International standards of power quality. Computer Business Equipment Manufacturers
Associations (CBEMA) curve.
UNIT II VOLTAGE SAGS AND INTERRUPTIONS 9
Sources of sags and interruptions - estimating voltage sag performance. Thevenin’s equivalent
source - analysis and calculation of various faulted condition. Voltage sag due to induction motor
starting. Estimation of the sag severity - mitigation of voltage sags, active series compensators.
Static transfer switches and fast transfer switches.
UNIT III OVERVOLTAGES 9
Sources of over voltages - Capacitor switching – lightning - ferro resonance. Mitigation of voltage
swells - surge arresters - low pass filters - power conditioners. Lightning protection – shielding - line
arresters - protection of transformers and cables. An introduction to computer analysis tools for
transients, PSCAD and EMTP.
UNIT IV HARMONICS 9
Harmonic sources from commercial and industrial loads, locating harmonic sources. Power system
response characteristics - Harmonics Vs transients. Effect of harmonics - harmonic distortion -
voltage and current distortion - harmonic indices - inter harmonics – resonance. Harmonic distortion
evaluation - devices for controlling harmonic distortion - passive and active filters. IEEE and IEC
UNIT V POWER QUALITY MONITORING 9
Monitoring considerations - monitoring and diagnostic techniques for various power quality problems
- modeling of power quality (harmonics and voltage sag) problems by mathematical simulation tools -
power line disturbance analyzer –
quality measurement equipment - harmonic / spectrum analyzer - flicker meters - disturbance
analyzer. Applications of expert systems for power quality monitoring.
TOTAL : 45 PERIODS
1. Roger. C. Dugan, Mark. F. McGranagham, Surya Santoso, H.Wayne Beaty, ‘Electrical Power
Systems Quality’ McGraw Hill,2003.(For Chapters1,2,3, 4 and 5)
1. G.T. Heydt, 'Electric Power Quality', 2nd Edition. (West Lafayette, IN, Stars in a
Circle Publications, 1994). (For Chapter 1, 2, 3 and 5)
2. M.H.J Bollen, ‘Understanding Power Quality Problems: Voltage Sags and Interruptions’, (New
York: IEEE Press, 1999). (For Chapters 1, 2, 3 and 5)
3. J. Arrillaga, N.R. Watson, S. Chen, 'Power System Quality Assessment', (New York: Wiley,
1999). (For Chapters 1, 2, 3, 4 and 5)
4. PSCAD User Manual