JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

Prerequisite

Electrical Machines-I, Electrical Machines-II

Course Objectives:

• To know the major considerations in electrical machine design, electrical engineering materials, space factor, choice of specific electrical and magnetic loadings,
• To analyze the thermal considerations, heat flow, temperature rise, rating of machines.
• To understand the design of transformers
• To study the design of induction motors
• To know the design of synchronous machines
• To understand the CAD design concepts

Course Outcomes

At the end of this course, students will demonstrate the ability to

• Understand the construction and performance characteristics of electrical machines.
• Understand the various factors which influence the design: electrical, magnetic and thermal loading of electrical machines
• Understand the principles of electrical machine design and carry out a basic design of an ac machine.
• Use software tools to do design calculations.

UNIT - I

Introduction Major considerations in electrical machine design, electrical engineering materials, space factor, choice of specific electrical and magnetic loadings, thermal considerations, heat flow, temperature rise, rating of machines.

UNIT - II

Transformers Sizing of a transformer, main dimensions, kVA output for single- and three-phase transformers, window space factor, overall dimensions, operating characteristics, regulation, no load current, temperature rise in transformers, design of cooling tank, methods for cooling of transformers.

UNIT - III

Induction Motors Sizing of an induction motor, main dimensions, length of air gap, rules for selecting rotor slots of squirrel cage machines, design of rotor bars & slots, design of end rings, design of wound rotor, magnetic leakage calculations, leakage reactance of poly-phase machines, magnetizing current, short circuit current, circle diagram, operating characteristics.

UNIT - IV

Synchronous Machines Sizing of a synchronous machine, main dimensions, design of salient pole machines, short circuit ratio, shape of pole face, armature design, armature parameters, estimation of airgap length, design of rotor, design of damper winding, determination of full load field mmf, design of field winding, design of turbo alternators, rotor design.

R18 B.TECH EEE III YEAR

UNIT - V

Computer Aided Design (CAD) Limitations (assumptions) of traditional designs need for CAD analysis, synthesis and hybrid methods, design optimization methods, variables, constraints and objective function, problem formulation. Introduction to FEM based machine design. Introduction to complex structures of modern machines- PMSMs, BLDCs, SRM and claw-pole machines.

TEXT BOOKS:

• 1. A. K. Sawhney, “A Course in Electrical Machine Design”, Dhanpat Rai and Sons, 1970.
• 2. M.G. Say, “Theory & Performance & Design of A.C. Machines”, ELBS London.

REFERENCES:

• 1. S. K. Sen, “Principles of Electrical Machine Design with computer programmes”, Oxford and IBH Publishing, 2006.
• 2. K. L. Narang, “A Text Book of Electrical Engineering Drawings”, Satya Prakashan, 1969.
• 3. A. Shanmugasundaram, G. Gangadharan and R. Palani, “Electrical Machine Design Data Book”, New Age International, 1979.
• 4. M. V. Murthy, “Computer Aided Design of Electrical Machines”, B.S. Publications, 2008.
• 5. Electrical machines and equipment design exercise examples using Ansoft’s Maxwell 2D machine design package. R18 B.TECH EEE III YEAR