JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

Prerequisite

Power Systems

Course objectives:

• To analyze the electrical transients in power systems.
• To impart the concepts of traveling waves and propagation.
• To discuss issues related to insulation coordination, grounding and limiting of surge effects.
• To develop the techniques related to transition points in transmission lines and cables.

Course Outcomes

After Completion of this course, student will be able to

• Analyze the electrical transients in power systems.
• Describe the issues related to insulation coordination, grounding and limiting of surge effects.
• Develop the techniques related to transition points in transmission lines and cables.

UNIT - I

Basic Concepts and Simple Switching Transients: Switching an LR, LC, RLC circuits Transients Analysis of Three-Phase power Systems: Symmetrical components in Three-phase Systems, Sequence Components for Unbalanced Network Impedances, the Sequence Networks, analysis of Unsymmetrical Three-Phase Faults-single line-to-Ground Fault, Three phase-to-ground faults.

UNIT - II

Travelling Waves: Velocity of Travelling waves and Characteristic Impedance, Energy Contents of Travelling Waves, Attenuation and Distortion of Electromagnetic Waves, telegraph equations-lossless line, distortion less line, Reflection and Refraction of Travelling Waves, Reflection of Travelling Waves against Transformer-and-Generator-windings, the Origin Transient Recovery voltages, the lattice diagram.

UNIT - III

Circuit Breakers: Switching arc, Oil Circuit Breakers, Air-Blast, SF6 Circuit Breakers, Vacuum Circuit Breakers, Modelling of the Switching Arc, Arc-Circuit Interaction. Switching Transients: Interrupting Capacitive currents, Capacitive Inrush currents, Interrupting Small Inductive Currents, Transformer Inrush currents, Short Line Fault.

UNIT - IV

Power System Transient Recovery Voltages: Characteristics of the Transient Voltage- Short-circuit test duties based on IEC 60056 (1987),ANSI/IEEE Standards, the Harmonization between IEC and ANSI/IEEE Standards with respect to Short-circuit Test duties, Transient recovery voltage for Different types of faults.

UNIT - V

Lightning – Induced Transients: Mechanism of Lightning, Wave shape of the lightning current, direct lighting Stroke to transmission line towers, direct lightening stroke to a line. Numerical simulation of electrical transients: The Electromagnetic Transient Program, The MNA Program, The X- Trans Program.

TEXT BOOKS:

• 1. “Transients in Power Systems”, by Lou van der Sluis, John Wiley & Sons, Ltd, Chic ester, UK 2002.
• 2. “Power System Transients: Theory and Applications”, by Akihiro Ametani, Naoto Nagaoka, Yoshihiro Baba, Teruo Ohno, CRC Press 2013.
• 3. “Electrical Transients in Power Systems”, by Allan Greenwood, Wiley-Interscience; 2 edition, April 1991.

REFERENCES:

• 1. “Power System Transients: A Statistical Approach”, by C.S Indulkar, D.P. Kothari, K. Ramalingam, PHI, 2 edition, 2010.
• 2. “Electrical Transients in Power Systems”, by Allan Greenwood Wiley India Private Limited; Second edition, July 2010. M. Tech – I Year – II Sem. (PS H.V. Engg. / H.V. Engg.)