Analysis of doubly fed slip-ring machines

It is shown that a broad class of machines exists whose members may be regarded as doubly fed slip-ring machines. The paper presents a simple approach to the analysis of the steady-state performance of such machines, and indicates the interrelation between a number of conventional machines and other less orthodox machines. In particular, the double-speed doubly fed machine is examined in some detail, and it is shown theoretically that the peak-power capability of this machine when acting as a motor is greater than that of any comparable form of machine.