viii CONTENTS 



PAGE 



CHAPTER VI. EXCITING AMPERE-TURNS IN ELECTRICAL MACHINERY. 



(Continued) 100 



The ampere-turns required for saturated teeth. The ampere- 

 turns for the armature core and for the field frame. Magnetic 

 leakage between field poles. The permeance and reluctance of irreg- 

 ular paths. The law of flux refraction. 



CHAPTER VII. MAGNETOMOTIVE FORCE OF DISTRIBUTED WINDINGS ... 121 



The m.m.f. of a direct-current or single-phase distributed wind- 

 ing. The m.m.f. of polyphase windings. The m.m.fs. in a loaded 

 induction machine. The higher harmonics of the m.m.fs. 



CHAPTER VIII. ARMATURE REACTION IN SYNCHRONOUS MACHINES. ... 139 



Armature reaction and armature reactance in a synchronous 

 machine. The performance diagram of a synchronous machine 

 with non-salient poles. The direct and transverse armature reac- 

 tion in a synchronous machine with salient poles. The Blondel 

 performance diagram of a synchronous machine with salient poles. 

 The calculation of the value of the coefficient of direct reaction. The 

 calculation of the value of the coefficient of transverse reaction. 



CHAPTER IX. ARMATURE REACTION IN DIRECT-CURRENT MACHINES .... 163 



The direct and transverse armature reactions. The calculation 

 of the field ampere-turns in a direct-current machine under load. 

 Commutating poles and compensating windings. Armature reac- 

 tion in a rotary converter. 



CHAPTER X. ELECTROMAGNETIC ENERGY AND INDUCTANCE 177 



The energy stored in an electromagnetic field. Electromagnetic 

 energy expressed through the linkages of current and flux. Induc- 

 tance as the coefficient of stored energy, or the electrical inertia of a 

 circuit. 



CHAPTER XI. THE INDUCTANCE OF CABLES AND OP TRANSMISSION 



LINES 189 



The inductance of a single-phase concentric cable. The mag- 

 netic field created by a loop of two parallel wires. The inductance 

 of a single-phase line. The inductance of a three-phase line with 

 symmetrical and semi-symmetrical spacing. The equivalent reac- 

 tance and resistance of a three-phase line with an unequal spacing of 

 the wires. 



CHAPTER XII. THE INDUCTANCE OF THE WINDINGS OF ELECTRICAL 



MACHINERY 208 



The inductance of transformer windings. The equivalent leak- 

 age permeance of armature windings. The leakage reactance in 

 induction machines. The leakage reactance in synchronous machines. 

 The reactance voltage of coils undergoing commutation 



