xiv • CONTENTS

CHAPTER X. HYSTERESIS MOTOR.

PACK

1)8. Rotation of iron disc in rotating magnetic field—Equations-
Motor below, generator above synchronism........16S

09. Derivation of equations from hysteresis law—Hysteresis torque
of standard induction motor, and relation to size......1(39

100. General discussion of hysteresis motor—Hysteresis loop
collapsing or expanding...........,.....170

CHAPTER XI. ROTARY TERMINAL SINGLE-PHASE INDUCTION MOTORS.

101. Performance and method of operation of rotary terminal
single-phase induction Motor—Relation of motor speed to

. brush speed and slip corresponding to the load.......172

102. Application of the principle to a self-starting single-phase power
motor with high starting and accelerating torque, by auxiliary
motor carrying brushes.........'........173

CHAPTER' XII. FREQUENCY CONVERTER OR GENERAL ALTERNATING
CURRENT TRANSFORMER.

103. The principle of the frequency converter or general alternating
current transformer—Induction motor and transformer special
cases—Simultaneous transformation between primary elec-
trical and secondary electrical power, and between electrical
and mechanical power—Transformation of voltage and of fre-
quency—The air-gap and its effect............176

104. Relation of e.m.f., frequency, number of turns and exciting
current........................177

105. Derivation of the general alternating current transformer—
Transformer equations and induction motor equations, special
cases thereof......................178

106. Equation of power of general alternating current transformer . 182

107. Discussion: between synchronism and standstill—Backward
driving—Beyond synchronism—Relation between primary
electrical, secondary electrical and mechanical power . . . .184

108. Calculation of numerical instance............185

109. The characteristic curves: regulation curve, compounding
curve—Connection of frequency converter with synchronous
machine, and compensation for lagging current—Derivation of
equation and numerical instance.............186

110. Over-synchronous operation—Two applications, as double
synchronous generator, and as induction generator, with low
frequency exciter....................190

111. Use as frequency converter—Use of synchronous machine or
induction machine as second machine—Slip of frequency—
Advantage of frequency converter over motor generator . . .191

112. Use of frequency converter—Motor converter, its advantages
and disadvantages—Concatenation for multispeed operation . 192