JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

Prerequisite

Power Systems-I & Power Systems –II

Course Objectives:

• To understand and develop Ybus and Zbus matrices
• To know the importance of load flow studies and its importance
• To analyse various types of short circuits
• To know rotor angle stability of power systems

Course Outcomes

After this course, the student will be able to

• Develop the Ybus and Zbus matrices
• Analyze load flow for various requirements of the power system
• Analyze short circuit studies for the protection of power system
• Estimate stability and instability in power systems

UNIT - I

Power System Network Matrices: Graph Theory: Definitions and Relevant concepts in Graph Theory, Network Matrices. Transmission Network Representations: Bus Admittance frame and Bus Impedance frame. Formation of Ybus: Direct and Singular Transformation Methods, Numerical Problems. Formation of ZBus: Modification of existing ZBus Matrix for addition of a new branch, & complete ZBus building algorithm Numerical Problems.

UNIT - II

Power Flow Studies – I: Introduction: Necessity of Power Flow Studies, Bus classification and Notations, Convergence & Bus mismatch criteria. Load Flow Methods: Gauss-Seidal Method in complex form without & with voltage control buses, line flows and loss calculations, Newton Raphson method in Polar and Rectangular form, derivation of Jacobian elements, Numerical Problems for one or two iterations.

UNIT - III

Power Flow Studies - II: Introduction to sensitivity & decoupled sub matrices of J-matrix, Decoupled load flow method and its assumptions, Fast Decoupled load method and its assumptions, Comparison of Different Methods – DC load Flow method, Numerical problems for one or two iterations.

R16 B.TECH EEE.

UNIT - IV

Short Circuit Analysis: Per-Unit Systems. Per-Unit equivalent reactance network of a three phase Power System, Numerical Problems. Symmetrical fault Analysis: Short Circuit Current and MVA Calculations, Fault levels, Application of Series Reactors, Numerical Problems. Symmetrical Components, sequence impedances and networks, Numerical Problems. Unsymmetrical Fault Analysis: Fault current calculations for LG, LL, LLG faults with and without fault impedance, Numerical Problems.

UNIT - V

Power System Stability Analysis: Introduction to Power System Stability issues. Rotor dynamics & Swing equation, Power angle equation with & without neglecting line resistance, Steady State Stability, Determination of Transient Stability through Equal Area Criterion for single machine infinite system, Critical clearing angle & time, Numerical problems. Multi- machine transient analysis: Classical representation of system and its assumptions, Solution of Swing Equation by Point-by-Point Method, Methods to improve Stability.

TEXT BOOKS:

• 1. “I. J. Nagrath & D. P. Kothari”, “Modern Power system Analysis”, Tata McGraw-Hill Publishing Company, 4 th Edition 2011.
• 2. “Hadi Saadat”, “Power System Analysis”, TMH Edition, 2002.

REFERENCE BOOKS:

• 1. “M. A. Pai”, “Computer Techniques in Power System Analysis”, TMH Publications, 3rd Edition 2014.
• 2. Grainger and Stevenson, “Power System Analysis”, Tata McGraw Hill, 2003.
• 3. Abhijit Chakrabarthi and Sunita Haldar, “Power System Analysis Operation and Control”, 3rd Edition, PHI, 2010. R16 B.TECH EEE.