Conception of optimum frequency control of an asynchronous traction electric drive

The control method of a traction electric drive with an asynchronous electric engine with a short-circuit rotor through the maintenance of the constancy of the relative angular slip frequency of the rotor is substantiated. The analytical of relationships for efficiency, cosφ, and the mechanical rigidity of the moment characteristic by determining variations in the electromagnetic time constant of the rotor are presented. The basic requirements for the optimum algorithm of the asynchronous engine control via setting the value of the phase current or the main magnetic-flux linkage and maintaining the constancy of the relative slip frequency of the rotor are formulated. © 2009 Allerton Press, Inc.