POWER QUALITY(SYLLABUS MTECH-EPS ELECTIVE I SEM)

UNIT-I: INTRODUCTION
Introduction of the Power Quality (PQ) problem, Terms used in PQ: Voltage, Sag, Swell, Surges,
Harmonics, over voltages, spikes, Voltage fluctuations, Transients, Interruption, overview of
power quality phenomenon, Remedies to improve power quality, power quality monitoring.
UNIT-II: LONG & SHORT INTERRUPTIONS
Interruptions – Definition – Difference between failures, outage, Interruptions – causes of Long
Interruptions – Origin of Interruptions – Limits for the Interruption frequency – Limits for the
interruption duration – costs of Interruption – Overview of Reliability evaluation to power quality,
comparison of observations and reliability evaluation.
Short interruptions: definition, origin of short interruptions, basic principle, fuse saving, voltage
magnitude events due to re-closing, voltage during the interruption, monitoring of short
interruptions, difference between medium and low voltage systems. Multiple events, single phase
tripping – voltage and current during fault period, voltage and current at post fault period,
stochastic prediction of short interruptions.

UNIT III: 1 & 3-PHASE VOLTAGE SAG CHARACTERIZATION
Voltage sag – definition, causes of voltage sag, voltage sag magnitude, and monitoring,
theoretical calculation of voltage sag magnitude, voltage sag calculation in non-radial systems,
meshed systems, and voltage sag duration.
Three phase faults, phase angle jumps, magnitude and phase angle jumps for three phase
unbalanced sags, load influence on voltage sags.
UNIT-IV: POWER QUALITY CONSIDERATIONS IN INDUSTRIAL POWER SYSTEMS
Voltage sag – equipment behavior of Power electronic loads, induction motors, synchronous
motors, computers, consumer electronics, adjustable speed AC drives and its operation.
Mitigation of AC Drives, adjustable speed DC drives and its operation, mitigation methods of DC
drives.
UNIT-V: MITIGATION OF INTERRUPTIONS & VOLTAGE SAGS
Overview of mitigation methods – from fault to trip, reducing the number of faults, reducing the
fault clearing time changing the power system, installing mitigation equipment, improving
equipment immunity, different events and mitigation methods. System equipment interface –
voltage source converter, series voltage controller, shunt controller, combined shunt and series
controller.
Power Quality and EMC Standards:
Introduction to standardization, IEC Electromagnetic compatibility standards, European voltage
characteristics standards, PQ surveys.
REFERENCE BOOK:
1. “Understanding Power Quality Problems” by Math H J Bollen. IEEE Press.
2. Power Quality VAR Compensation in Power Systems, R. SastryVedam Mulukutla S.
Sarma,CRC Press.
3. Power Quality, C. Sankaran, CRC Presss.
4. Electrical Power Systems Quality, Roger C. Dugan , Mark F. Mc Granaghan, Surya
Santoso, H. Wayne Beaty, Tata McGraw Hill Education Private Ltd.