BOOK REVIEWS 36I
loading of the stator and the magnetic field component of the rotor, for the mutual torque reaction between stator and rotor, together with corresponding power relations. The analysis extends to complex wave forms and the method of harmonic separation into wave trains, including the flux distribution in the core and teeth. Chapters I to V cover basic theory common to all a-c. electrical machines, as well as circuit analysis including special features such as the treatment of Kelvin's law, the calculation of torque by differentiating the gap energy with respect to the displacement between rotor and stator fields, and in the use of the Null unit function for transient circuit relations. The author discusses over-all characteristics, including torque-current vs. speed relations, the circle diagram and power losses, as well as performance calculations at start, power-factor determination and dynamic braking.
Chapters from VI on are more concerned with detail of particular value to the designer. The author discusses saturation conditions at teeth, slip, core and friction-windage losses with a careful presentation of reactance calculations for slots, including zero phase sequence and the zigzag reactance. The theory of belt and end coil leakage is included, together with the Rfidenberg flux distribution equations in the core. A thorough discussion of speed torque relations covers basic limitations in starting as heat losses proportional to torque-tiines slip with high starting currents, and means for reducing these losses through rotor resistance and the design of deep and idle bar rotors. Squirrel cage rotors, pole changing and concatenation methods are discussed. The remaining chapters cover unique matters on crawling and locking phenomena, noise and voltage ripples and on the general subject of ratings.
The book is a fundamental contribution of permanent value to the field of electrical machinery, both from a theoretical and a design point of view.
RUPEN EKSERGIAN