JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

Prerequisite

Computer Methods in Power Systems

Course Objectives:

• To analyze a Power System Network using graph theory.
• To interpret the formation of Network matrices.
• To construct the necessity of load flow studies and various methods of Analysis.
• To examine short circuit analysis using ZBus.

Course Outcomes

Upon the completion of the subject, the student will be able to

• Remember proper mathematical models for analysis.
• Conclude methodologies of load flow studies for the power network.
• Apply contingency Analysis.
• Analyze power system studies.

UNIT - I

Admittance Model and Network Calculations, Branch and Node Admittances, Mutually Coupled Branches in YBUS , An Equivalent Admittance Network, Modification of YBUS , Network Incidence Matrix and YBUS , Method of Successive Elimination, Node Elimination, Triangular Factorization, Sparsity and Near Optimal Ordering.

UNIT - II

Impedance Model and Network Calculations, the BUS Admittance and Impedance Matrices, Thevenin’s Theorem and ZBUS ,Algorithms for building ZBUS Modification of existing ZBUS, Calculation of ZBUS elements from YBUS, Power Invariant Transformations, Mutually Coupled Branches in ZBUS.

UNIT - III

Gauss Seidel method, N-R Method, Decoupled method, fast decoupled method, comparison between power flow solutions. DC load flow.

UNIT - IV

ZBUS Method in Contingency Analysis, Adding and Removing Multiple Lines, Piecewise Solution of Interconnected Systems, Analysis of Single Contingencies, Analysis of Multiple Contingencies, Contingency Analysis of DC Model, System Reduction for Contingency and Fault Studies.

UNIT - V

Fault Analysis: Symmetrical faults-Fault calculations using ZBUS- Fault calculations using ZBUS equivalent circuits –Selection of circuit breakers- Unsymmetrical faults-Problems on various types of faults.

TEXT BOOKS:

• 1. John J. Grainger and W. D. Stevenson, “Power System Analysis”- T.M.H. Edition.
• 2. Modern Power System Analysis– by I. J. Nagrath & D. P. Kothari Tata McGraw – Hill Publishing Company Ltd, 2nd edition.

REFERENCE BOOKS:

rd

• 1. Power System Analysis and Design by J. Duncan Glover and M.S. Sarma., Cengage 3 Edition.
• 2. Olle. L.Elgard, “Electrical Energy Systems Theory”-T.M.H. Edition.
• 3. Power systems stability and control, Prabha Kundur, The McGraw – Hill companies.
• 4. Power System Operation and Control, Dr. K. Uma Rao, Wiley India Pvt. Ltd.
• 5. Operation and Control in Power Systems, PSR Murthy, Bs Publications.
• 6. Power System Operation, Robert H. Miller, Jamesh H. Malinowski, The McGraw – Hill companies.
• 7. Power Systems Analysis, operation and control by Abhijit Chakrabarti, Sunitha Halder, PHI 3/e , 2010 M. TECH – I YEAR – I SEM. (EPE/EPS/PSC&A) ADVANCED POWER SYSTEM Protection (Professional Core - II)

Prerequisite

Switch Gear and Protection

Course Objectives:

• To distinguish all kinds of circuit breakers and relays for protection of Generators, Transformers and feeder bus bars from Over voltages and other hazards.
• To generalize neutral grounding for overall protection.
• To illustrate the phenomenon of Over Voltages and its classification.

Course Outcomes

Upon the completion of the subject, the student will be able to

• Understand the basic function of a circuit breaker, all kinds of circuit breakers and differentiate fuse and circuit breakers under fault condition.
• Describe the necessity for the protection of alternators, transformers and feeder bus bars from over voltages and other hazards
• Illustrate neutral grounding, and how over voltages can be generated and how system can be protected against lightning and switching transient over voltages with various protective means
• Identify operation and control of microprocessor based relays.

UNIT - I

Static Relays: Advantages of static relays-Basic construction of static relays-Level detectors-Replica impedance –Mixing circuits-General equation for two input phase and amplitude comparators-Duality between amplitude and phase comparators. Amplitude Comparators: Circulating current type and opposed voltage type- rectifier bridge comparators, Direct and Instantaneous comparators.

UNIT - II

Phase Comparators: Coincidence circuit type- block spike phase comparator, techniques to measure the period of coincidence-Integrating type-Rectifier and Vector product type- Phase comparators. Static Over Current Relays: Instantaneous over-current relay-Time over-current relays-basic principles –definite time and Inverse definite time over-current relays.

UNIT - III

Static Differential Relays: Analysis of Static Differential Relays –Static Relay schemes –Duo bias transformer differential protection –Harmonic restraint relay. Static Distance Relays: Static impedance-reactance–MHO and angle impedance relay-sampling comparator –realization of reactance and MHO relay using sampling comparator.

UNIT - IV

Multi-Input Comparators: Conic section characteristics-Three input amplitude comparator –Hybrid comparator-switched distance schemes –Poly phase distance schemes- phase fault scheme –three phase scheme – combined and ground fault scheme. Power Swings: Effect of power swings on the performance of distance relays –Power swing analysis-Principle of out of step tripping and blocking relays-effect of line and length and source impedance on distance relays.

UNIT - V

Microprocessor based Protective Relays: (Block diagram and flowchart approach only)-Over current relays–impedance relays-directional relay-reactance relay .Generalized mathematical expressions for distance relays-measurement of resistance and reactance –MHO and offset MHO relays-Realization of MHO characteristics- Realization of offset MHO characteristics -Basic principle of Digital computer relaying, Introduction to wide area control(qualitative).

TEXT BOOKS:

• 1. Badri Ram and D.N. Vishwakarma, “Power system protection and Switch gear “, TMH publication New Delhi 1995.
• 2. T.S. Madhava Rao , “Static relays”, TMH publication, second edition 1989.

REFERENCE:

• 1. Protection and Switchgear, Bhavesh Bhalja, R. P. Mahesheari, Nilesh G. Chothani, Oxford University Press.
• 2. Electrical Power System Protection, C. Christopoulos and A. Wright, Springer International. M. TECH – I YEAR – I SEM. (EPE/EPS/PSC&A)