Y. H. Ku's Relative Components. Application to the Analytic Study of an Asynchronous Motor Fed by a Self-Contained Inverter Operating as Current Switch.

The study of three-phase machines in transient conditions requires the substitution of relative components for the actual voltages and currents. As far as the asynchronous machine is concerned, the most handy ones are the components of Y. H. Ku. This transformation is first presented and the results it rendered possible in the study of transient conditions as such, and of the steady operation of a machine fed by an inverter supplying stepwise voltages, are recalled. A study of the motor fed by a three-phase current system composed of rectangular gates is presented. Obtaining literal expressions of the instantaneous values of voltages, currents, and torque makes it possible to estimate the effect of design parameters on characteristics, in particular, in the case considered here, on the torque jerks.