1. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 1 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I 17 Introduction to Electric Machines

2. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 2 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I Figure 17.4 Torque-speed and efficiency curves for an electric motor

3. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 3 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I Figure 17.6 Generator and motor action in an electric machine

4. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 4 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I Figure 17.8 A two-pole machine with salient stator poles Excitation currentI f Armature conductors Reaction torque Rotor torque Field winding Yoke Cross section of DC machine N S Pole + + ++ + + + + + + + + T B S B R T' m

5. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 5 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I Figure 17.15 Electrical circuit model of a separately excited DC machine

6. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 6 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I Figure 17.19 DC motor operating characteristics

7. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 7 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I Figure 17.25 Two-pole three-phase stator

8. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 8 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I Figure 17.37 (a) Squirrel-cage induction motor; (b) conductors in rotor; (c) photo of squirrel-cage induction motor; (d) views of Smokin’ Buckeye motor: rotor, stator, and cross section of stator

9. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 9 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I Figure 17.38 Circuit model for induction machine

10. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 10 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I Figure 17.39 Rotor circuit + – I R E R0 jX R0 R R S

11. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 11 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I Figure 17.40 Equivalent circuit of an induction machine

12. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 12 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I Figure 17.42 Performance curve for induction motor T,% 300 200 100 0 a b c d e No-load speed n s n

13. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 13 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I Figure 17.43 Induction motor classification T D C A B 300 200 100 0 nn s

14. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 14 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I Figure 17.45 General configuration of adjustable-frequency drive Intermediate circuit Control and regulation circuit Rectifier ~ ~ ~ Inverter Motor