xii CONTENTS 



ART. PAOB 



82. Tooth and slot proportions 259 



83. Length and resistance of armature winding 260 



84. Ventilation 261 



85. Full load developed voltage 261 



86. Inductance of A.C. armature windings 263 



87. Calculation of armature inductance 264 



88. Total losses to be radiated from armature core . , 266 



89. Temperature rise of armature 267 



CHAPTER XIII 

 AIR-GAP FLUX DISTRIBUTION WAVE SHAPES 



90. Shape of pole face 269 



91. Variation of permeance over pole pitch (Salient pole machines) . .271 



92. M.m.f. and flux distribution on open circuit (Salient pole machines) 272 



93. Special case of cylindrical field magnet with distributed winding . 272 



94. Armature m.m.f in alternating-current generators 274 



95. Slot leakage flux 281 



96. Calculation of slot leakage flux 284 



97. Effect of slot leakage on full-load air-gap flux 286 



98. Method of determining position of armature m.m.f 288 



99. Air-gap flux distribution under load 290 



100. Form of developed e.m.f. wave 291 



101. Form factor 294 



102. Equivalent sine waves 295 



CHAPTER XIV 

 REGULATION AND EFFICIENCY OF ALTERNATORS 



103. The magnetic circuit 299 



104. Regulation 301 



105. Factors influencing the inherent regulation of alternators .... 303 



106. Regulation on zero power factor 305 



107. Short-circuit current 308 



108. Regulation on any power factor 309 



109. Influence of flux distribution on regulation 311 



110. Outline of procedure in calculating regulation from study of e.m.f. 



waves 312 



111. Efficiency 317 



CHAPTER XV 

 EXAMPLE OF ALTERNATOR DESIGN 



112. Introductory 320 



113. Single-phase alternators 321 



114. Design sheets for 8000-kw. turbo-alternator 322 



115. Numerical example Calculations 324 



INDEX . 359 





