UNIT – I
INTRODUCTION AND SURVEY: Source of transients, various types of power systems transients, effect of transients on power systems, importance of study of transients in planning.
UNIT – II
SWITCHING TRANSIENTS: Introduction, circuit closing transients: RL circuit with sine wave drive, double frequency transients, observations in RLC circuit and basic transforms of the RLC circuit. Resistance switching: Equivalent circuit for the resistance switching problems, equivalent circuit for interrupting the resistor current. Load switching: Equivalent circuit, wave-forms for transient voltage across the load, 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: Causes of over voltage, lightning phenomenon, charge formation in the clouds, rate of charging of thunder clouds, mechanisms of lighting strokes, characteristics of lightning strokes, factors contributing to good line design, protection afforded by ground wires, tower footing resistance. INTERACTION BETWEEN LIGHTNING AND POWER SYSTEM: Mathematical model for lightning.
UNIT – IV
TRAVELLING WAVES ON TRANSMISSION LINE COMPUTATION OF TRANSIENTS: Transient response of systems with series and shunt lumped parameters and distributed lines. Travelling 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: The short line and kilometric fault, distribution of voltage 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; EMTP for transient computation.
UNIT – I