Course Objectives:

1.      To give overview of nature of power system transients

2.      To impart knowledge about the concept of travelling waves

3.      To explain the phenomenon of switching surges and lightning surges and its modelling.

4.      To impart knowledge of the criteria of insulation coordination and its standards

Introduction to Fast Transients: Origin and nature of power system transients, Traveling waves on transmission system, the line equation, the shape attenuation and distortion of waves, Reflection of traveling waves, Successive reflections, Traveling waves on multi conductor systems, Transition points on multi conductor circuits.


Lightning: Charge formation, Mechanism of lightning stroke, Mathematical model of lightning stroke.


Theory of Grounds Wires: Stoke to a tower, Effect of reflection up and down the tower, the counterpoise.


Switching Surges: Normal frequency effects, High charging currents, Cancellation waves, Recovery voltage, Restricting phenomena, Protection oftransmission systemsagainstsurge.

Insulation Coordination: Insulation coordination procedures (IEC) for high voltage systems: Design criteria, Classification of overvoltages, Insulation design for switching, Lightning and temporary overvoltages, Pollution, application of arresters for protection of lines and stations, Statistical methods of insulation coordination, Risk of failure, Test prescriptions. Insulation coordination procedures (IEC) for low voltage systems: Representative overvoltages, Selection of clearance and creepage distances, Macro and micro environments, testing techniques, Transient (switching and lightning) voltage surge suppression in industrial and commercial electrical installations, Protection of electronic devices.


Course Learning Outcome (COL): On the completion of the course, the student will be able

1.      To understand the causes and effects of switching and lightning surges

2.      To identify the protection schemes of power system equipment from overvoltages like ground wires, surge absorbers and arrestors.

3.      To design of insulation of power system components

4.      To carry out the insulation testing procedures


Recommended Books:

1.    Greenwood, A., Electrical Transients in Power Systems, Wiley Inter-Sscience (1991).

2.    Bewley, L..V., Travelling Waves on Transmission System, Power Publications Inc. (1993).

3.    Rudenterg, R., Electric Stroke Waves in Power Systems, Harvard University Press (1998).

4.    Gonen, T., Electric Power Transmission System Engineering: Analysis and Design, John Wiley and Sons (1997).