Electric generators

Front Cover
Offices of "Engineering", 1900 - Electric currents - 376 pages
 

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Contents

Magnetic Curves for Malleable Iron
21
Data of Ten FirstQuality Samples of Cast Steel
22
to 19 Magnetic Curves for Cast Steel
23
Data of Ten SecondQuality Samples of Cast Steel
24
Magnetic Curves for Mitis Iron
26
Analyses of Samples of Sheet Iron and Steel
27
Energy Losses in Sheet Iron
28
Effect of Temperature of Annealing on Hysteresis Loss in Sheet Iron
30
Results of Tests on Ageing of Iron
31
to 32 Ageing Curves for Sheet Iron
32
and 34 Effect of Pressure upon Hysteresis Loss in Sheet Iron
33
Curves for Hysteresis Loss in Sheet Iron
34
Properties of Iron and Steel with Special Reference to Specific Resistance
36
Influence of Carbon on Specific Resistance of Steel
37
Insulating Materials
38
Insulation Tests on Sheets of Leatheroid
39
Summary of Qualities of Insulating Materials
42
Characteristic Insulation Resistance Curve for Cloth
43
to 44 Apparatus for Insulation Tests
44
Insulation Tests on Mica Canvas
47
Circuit Connections for Insulation Tests
48
to 51 Insulation Curves for MicaCanvas 48 and
49
to 57 Insulation Curves for Mica Longcloth 50 and
51
Insulation Tests on Mica LongCloth
52
Insulation Tests on Shellacd Paper
53
to 63 Insulation Curves for Shellacd Paper
54
Insulation Tests on Red Paper
55
to 69 Insulation Curves for Red Paper
56
Armature Windings
60
Gramme Ring Winding with Lateral Commutator
61
MultipleCircuit Drum Winding
63
Six Circuit Double Winding
65
FIG PAGE 73 TwoCircuit Single Winding
67
Subdivision of Windings for Rotary Converters
70
TwoCircuit Double Winding
71
SixCircuit Winding for ThreePhase Rotary Converter
72
UniCoil SinglePhase Winding
74
ThreePhase Armature 10 Poles and 12 Coils
76
to 87 Induction Motor Windings
77
Formula for Electromotive Force
78
Drum Winding Constants
80
Correction Factors for Voltage of Distributed Windings
81
Values for K in E M F Calculations for MultiCoil Windings
82
Values for K in E M F Calculations for MultiCoil Windings with Various Pole Arcs
83
Types of Winding
84
Values for Voltage Ratio for Single and QuarterPhase Rotaiy Converters
85
Rotary Converter Characteristic Curves
86
and 91 Form Factor Curves
87
Valaes for Form Factor
88
Values for Form Factor
89
Thermal Limit of Outpdt
90
to 96 Thermal Tests of a Field Spool
94
and 98 Thermal Tests of a Field Spool 94 and
95
to 112 Thermal Tests of Influence of Peripheral Speed on Temperature Rise 96 to
101
XXTX Temperature Correction Coefficients for Copper
102
Armature Slot of a Large Alternator
105
to 116 Curves Relating to Core Loss in Railway Motor Armature 106 and
108
Magnetic Flux Densities in Sheet Iron and Corresponding Specific Rates of Generation of Heat in Watts per Pound
109
Curves of Rate of Generation of Heat in Copper by Resistance
110
Design of the Magnetic Circuit
115
119tol24 Leakage Factor Diagrams of Dynamos
120
Diagram for Illustrating Reluctance of Core Projections
123
to 160 Diagrams and Curves of Armature Inductance 161 to
174
Diagram for Illustrating Reactance Calculations
175
Description of Modern Constant Potential Commutating Dynamos
179
to 166 Drawings of 1500 Kilowatt Railway Generator 181 to
185
and 168 Saturation and Compounding Curves of 1500 Kilowatt Railway Generator
188
to 183 Drawings of 200Kilowatt Railway Generator 191 to
196
to 188 Results of Tests of 200Kilowatt Railway Generator
202
to 206 Drawings of 300Kilowatt Lighting Generator 204 to
213
to 233 Drawings of 250Kilowatt Electric Generator 216 to
226
28
228
and 238 Diagram and Curve for Calculating Core Losses in Multipolar Com mutating Machines
229
to 254 Drawings of 24 HorsePower Geared Railway Motor 234 to
240
Description of a 27 HorsePower Geared Railway Motor for a Rated Output
242
to 277 Drawings of 27 HorsePower Geared Railway Motor 242 to
250
to 283 Characteristic Curves of 27 HorsePower Geared Railway Motor 250 and
251
to 319 Drawings of 117 HorsePower Gearless Railway Motor 253 to
264
to 323 Characteristic Curves of 117 HorsePower Gearless Railway Motor
265
to 331 Commutators for Traction Motors 268 and
269
to 340 Commutators for Traction Generators 269 and
270
Diagram of Arrangements for Measuring Contact Resistance of Brushes
271
to 346 Curves of Properties of Commutator Brushes 271 to
274
to 352 Brush Holders for Radial Carbon Brushes for Traction Motors 275 and
276
to 358 Carbon Brush Holders for Generators 276 and
278
and 361 Bayliss Reactance Brush Holder
279
Rotary Converters
283
Sine Curves of Instantaneous Current Values in Three Phases of a Rotary Converter
286
Diagrams of Instantaneous Current Values in Line and Windings of a Rotary Converter
287
and 369 Developed Diagrams of Rotary Converter Winding 288 and
289
TwoCircuit Single Winding for SinglePhase Rotary
295
TwoCircuit Singly ReEntrant Triple Winding for SinglePhase Rotary
296
SixCircuit Single Winding
297
TwoCircuit Single Winding for ThreePhase Rotary
298
TwoCircuit Singly ReEntrant Triple Winding for ThreePhase Rotary
299
SixCircuit Single Winding for SixPhase Rotary
300
TwoCircuit Single Winding for SixPhase Rotary
301
TwoCircuit Singly ReEntrant Triple Winding for SixPhase Rotary
302
o
303
InterConnection of Static Transformers and Rotary Converter
304
and 382 DoubleDelta Connection and Diametrical Connection
305
SixPhase Switchboard
307
SixCircuit Single Winding for FourPhase Rotary
308
TwoCircuit Single Winding for FourPhase Rotary
309
TwoCircuit Triple Winding for FourPhase Rotary
310
and 389 Connection Diagrams for TwelvePhase Rotary Converter
311
to 393 Drawings of SixPhase 400Kilowatt Rotary 313 to
315
and 395 Curves of SixPhase 400Kilowatt Rotary
316
to 398 Drawings of ThreePhase 900Kilowatt Rotary 331 and
332
to 402 Characteristic Curves of ThreePhase 900Kilowatt Rotary
333
Diagram of Connections for Starting Rotary Converter by Compensator Method
341
and 405 Methods of Synchronising Rotary Converters
343
to 408 ThreePole 2000 Ampere 330Volt Switch for Rotary Converters 344 and
345
Diagram of Connections for Using Induction Regulators for Controlling the Voltage Ratio in Rotary Converters
347
Diagram of Connections for Controlling the Voltage Ratio in Rotary Converter System by an Auxiliary Booster
348
Diagram of Connections for Controlling the Voltage Ratio on a Portion of a Rotary Converter System by an Auxiliary Booster
349
Combined Rotary Converter and Series Booster
350
to 418 Phase Characteristic Curves of Rotary Converters 354 to
357
and 420 Distribution of Resultant Armature Magnetomotive Force over the Armature Surface of a Rotary Converter 358 and
359
Curves of a SeriesWound Rotary
363
Curves of a Rotary without Field Excitation
364
Appendix
367
Curve for Sheet Iron at High Densities
372
Index
373

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Page 281 - ... direct-current generator. Another point of difference is in the relative dimensions of the magnetic circuit, including yoke and magnet cores, which are smaller than would be usual or desirable in ordinary direct-current generators. Under the usual condition of running, the armature is driven, as in a simple synchronous motor, by alternating current supplied to the collector rings from an external source. While so revolving direct current can be taken from brushes bearing upon the commutator....
Page 78 - M = the magnetic flux (number of cgs lines) included or excluded by each of the T turns in a magnetic cycle. V, the voltage, is approximately constant during any period considered, and is the integral of all the voltages successively set up in the different armature coils according to their position in the magnetic field ; and since in this case only average voltages are considered, the resultant voltage is independent of any manner in which the magnetic flux may vary through the coils. Therefore...
Page 16 - ... that, beginning with the most impure cast iron, and passing through the several grades of cast iron, steel and wrought iron, the magnetic properties accord principally with the amounts of carbon present, and in a lesser degree with the proportions of...
Page 158 - T turns ; hence the product of flux and turns, ie, the total linkage, the inductance of the coil, is proportional to the square of the number of turns in the coil.
Page 78 - TNM i0-8, in which V = the voltage generated in the armature. T = the number of turns in series between the brushes. N = the number of magnetic cycles per second. M = the magnetic flux (number of cgs lines) included or excluded by each of the T turns in a magnetic cycle.
Page 302 - ... three-phase alternating currents into two-phase alternating currents. For three-phase rotary converters, the transformers should preferably be connected in A, as this permits the system to be operated with only two transformers, in case the third has to be cut out of the circuit temporarily for repairs.
Page 150 - We find, therefore, that while in the first case the armature strength is small, the voltage between segments is excessive. In the second case, while the voltage between segments is small, the armature is altogether too strong. With but two poles, some intermediate value would have to be sought for both quantities ; probably something like 100 turns would give a fairly good result. CONDITIONS ESSENTIAL то SPARKLESS COMMUTATION As a consequence of armature reaction and inductance it becomes not...
Page 302 - six-phase," with six collector rings. This requires in each case subdividing the winding up into just twice as many sections as for the case of three-phase windings. A study of these windings will show that with these connections with six sections (where before there were three), the first and fourth, second and fifth, and third and sixth, taken in pairs, give a distribution of the conductors, suitable for a three-phase winding, each of the above pairs constituting a phase. Furthermore, each portion...
Page 153 - Suppose, for instance, a 10-kw. 100-volt generator, with an armature strength of 2000 * If only two sets of brushes are retained the short-circuited set of conductors no longer consists of the two corresponding to one turn, but now includes as many in series as there are poles. A high reactance voltage is consequently present in this short-circuited set. The presence of the full number of sets of brushes, if correctly adjusted, should reduce this, but cannot in practice be relied upon to do so. Diagrams...

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