R18 B.TECH EEE
EE402PC: ELECTRICAL MACHINES – II
II Year B.Tech. EEE II-Sem L T P C
3 1 0 4
Prerequisite: Basic Electrical Engineering, Electrical Machines-I
Course Objectives:
- To deal with the detailed analysis of poly-phase induction motors & Alternators
- To understand operation, construction and types of single phase motors and their applications in house hold appliances and control systems.
- To introduce the concept of parallel operation of alternators
- To introduce the concept of regulation and its calculations.
Course Outcomes: At the end of this course, students will demonstrate the ability to
- Understand the concepts of rotating magnetic fields.
- Understand the operation of ac machines.
- Analyze performance characteristics of ac machines.
UNIT - I
Poly-Phase Induction Machines: Constructional details of cage and wound rotor machines production of a rotating magnetic field - principle of operation - rotor EMF and rotor frequency - rotor reactance, rotor current and Power factor at standstill and during operation.
UNIT - II
Characteristics of Induction Machines: Rotor power input, rotor copper loss and mechanical power developed and their interrelation-torque equation-deduction from torque equation - expressions for maximum torque and starting torque - torque slip characteristic - equivalent circuit - phasor diagram - crawling and cogging -.No-load Test and Blocked rotor test –Predetermination of performance- Methods of starting and starting current and Torque calculations.
Speed Control Methods: Change of voltage, change of frequency, voltage/frequency, injection of an EMF into rotor circuit (qualitative treatment only)-induction generator-principle of operation.
UNIT - III
Synchronous Machines: Constructional Features of round rotor and salient pole machines – Armature windings – Integral slot and fractional slot windings; Distributed and concentrated windings – distribution, pitch and winding factors – E.M.F Equation. Harmonics in generated e.m.f. – suppression of harmonics – armature reaction - leakage reactance – synchronous reactance and impedance – experimental determination - phasor diagram – load characteristics. Regulation by synchronous impedance method, M.M.F. method, Z.P.F. method and A.S.A. methods – salient pole alternators – two reaction analysis – experimental determination of Xd and Xq (Slip test) Phasor diagrams – Regulation of salient pole alternators.
UNIT - IV
Parallel Operation of Synchronous Machines: Synchronizing alternators with infinite bus bars – synchronizing power torque – parallel operation and load sharing - Effect of change of excitation and mechanical power input. Analysis of short circuit current wave form – determination of sub-transient, transient and steady state reactance’s.
Synchronous Motors: Theory of operation – phasor diagram – Variation of current and power factor with excitation – synchronous condenser – Mathematical analysis for power developed .- hunting and its suppression – Methods of starting – synchronous induction motor.
UNIT – V
Single Phase & Special Machines: Single phase induction motor – Constructional features-Double revolving field theory – split-phase motors – shaded pole motor.
TEXT BOOKS:
- A. E. Fitzgerald and C. Kingsley, "Electric Machinery”, McGraw Hill Education, 2013.
- M. G. Say, “Performance and design of AC machines”, CBS Publishers, 2002.
REFERENCE BOOKS:
- P. S. Bimbhra, “Electrical Machinery”, Khanna Publishers, 2011.
- I. J. Nagrath and D. P. Kothari, “Electric Machines”, McGraw Hill Education, 2010.
- A. S. Langsdorf, “Alternating current machines”, McGraw Hill Education, 1984.
- P. C. Sen, “Principles of Electric Machines and Power Electronics”, John Wiley & Sons, 2007.
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CreatedDec 13, 2020
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UpdatedDec 13, 2020
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