CONTENTS

power factor and at constant field excitation—Comparison
with induction motor..................(57
48. Comparison of induction motor and synchronous motor regard-
ing armature reaction and synchronous impedance—Poor
induction motor makes good, and good induction motor makes
poor synchronous motor................ 69
Induction Motor Concatenated nnth Synchronous
47. Synchronous characteristic and synchronizing speed of con-
catenated couple—Division of load between machines—The
synchronous machine as small exciter .'..........71
48. Equation of concatenated couple of synchronous and induction
motor—Reduction to standard synchronous motor equation . 72
49. Equation of power output and input of concatenated couple . 74
50. Calculation of numerical instance of 56 polar high excitation
induction motor concatenated to 4 polar synchronous .... 75
51. Discussion. High power factor at all loads, at constant
synchronous motor excitation..............7(5
Induction Motor Concatenated with Cmnmutati-ng Machine
52. Concatenated couple with commutating machine asynchronous
—Series and shunt excitation—Phase relation adjustable—
Speed control and power factor control—Two independent
variables with concatenated commutating machine, against one
with synchronous machine—Therefore greater variety of speed
and load curves....................78
53. Representation of the commutating machine by an effective
impedance, in which both components may be positive or
negative, depending on position of commutator brushes ... 80
54. Calculation of numerical instance, with commutating machine
series excited for reactive anti-inductive voltage—Load curves
and their discussion..................82
Induction Motor with Condenser in Secondary Circuit
55. Shunted capacity neutralizing lagging current of induction
motor—Numerical instance—Effect of wave shape distortion-
Condenser in tertiary circuit of single-phase induction motor—-
Condensers in secondary circuit—Large amount of capacity
required by low frequency................84
56. Numerical instance of low speed high excitation induction,
motor with capacity in secondary—Discussion of load curves
and of speed................"......86
57. Comparison of different methods of secondary excitation, by
power factor curves: low at all loads; high at all loads, low at
light, high at heavy loads—By speed: synchronous or constant
speed motors and asynchronous motors in which the speed
decreases with increasing load..............88