Design Calculations for A-C Generators

This paper presents simplified formulas and curves for rapid and accurate evaluation of steady-state and transient performance of a-c generators. The calculations provide for the determination of no-load, zero-power-factor and full-load field current, short-circuit ratio, leakage reactance, synchronous reactance, transient reactance, substransient reactance, transient open-circuit and short-circuit time constants, and d-c time constant. A simple formula is proposed for rough approximation of no-load core loss. These formulas and curves apply to very small machines with semi-enclosed slots, very short air gaps and high flux densities in the iron, as well as to the larger machines covered by previous papers on this subject.