EE2027 POWER SYSTEM TRANSIENTS L T P C
3 0 0 3
To review the over voltages (or) surges due to the phenomena of switching operations and lighting
discharge. Also to study propagation, reflection and refraction of these surges on the equipments
their impact on the power system grid.
To study the generation of switching transients and their control using circuit – theoretical concept.
To study the mechanism of lighting strokes and the production of lighting surges.
To study the propagation, reflection and refraction of travelling waves.
To study the impact of voltage transients caused by faults, circuit breaker action, load rejection on
integrated power system.
UNIT I INTRODUCTION AND SURVEY 9
Review and importance of the study of transients - causes for transients.
RL circuit transient with sine wave excitation - double frequency transients - basic transforms of the
RLC circuit transients.
Different types of power system transients - effect of transients on power systems – role of the study
of transients in system planning.
UNIT II SWITCHING TRANSIENTS 9
Over voltages due to switching transients - resistance switching and the equivalent circuit for
interrupting the resistor current - load switching and equivalent circuit - waveforms for transient
voltage across the load and the switch - normal and abnormal switching transients. Current
suppression - current chopping - effective equivalent circuit. Capacitance switching - effect of source
regulation - capacitance switching with a restrike, with multiple restrikes. Illustration for multiple
restriking transients - ferro resonance.
UNIT III LIGHTNING TRANSIENTS 9
Review of the theories in the formation of clouds and charge formation - rate of charging of thunder
clouds – mechanism of lightning discharges and characteristics of lightning strokes – model for
lightning stroke - factors contributing to good line design - protection using ground wires - tower
footing resistance - Interaction between lightning and power system.
UNIT IV TRAVELING WAVES ON TRANSMISSION LINE COMPUTATION OF
Computation of transients - transient response of systems with series and shunt lumped parameters
and distributed lines. Traveling wave concept - step response - Bewely’s lattice diagram - standing
waves and natural frequencies - reflection and refraction of travelling waves.
UNIT V TRANSIENTS IN INTEGRATED POWER SYSTEM 9
The short line and kilometric fault - distribution of voltages in a power system - Line dropping and
load rejection - voltage transients on closing and reclosing lines - over voltage induced by faults -
switching surges on integrated system
Qualitative application of EMTP for transient computation.
TOTAL : 45 PERIODS TEXT BOOKS
1. Allan Greenwood, ‘Electrical Transients in Power Systems’, Wiley Interscience, New York, 2nd
2. R.D.Begamudre, ‘Extra High Voltage AC Transmission Engineering’, Wiley Eastern Limited,
1. M.S.Naidu and V.Kamaraju, ‘High Voltage Engineering’, Tata McGraw Hill, 2nd edition, 2000.