The cascade induction machine: A reliable and controllable motor or generator

This paper discusses and analyses a set of two induction machines, with 2p and 2q pole-pairs, respectively, connected in cascade. It highlights the design and development principles of a single unit version of a system consisting of two wire-wound rotor induction machines with their rotors connected in cascade. Presented performance analysis shows the described cascade machine, which is brushless and with no slip rings or commutators, as a reliable, efficient and practical machine that could replace the induction machine, which has a wire-wound rotor. An example of the conversion of a standard squirrel cage six pole induction machine into a (6+2) pole induction machine, without rewinding the stator, is also presented together with simulation and measurements for asynchronous and synchronous modes of operation.