Quick-response torque control of induction motor with robustness against variations of primary and secondary resistances

Abstract

This paper proposes a novel quick-response torque control strategy of an induction motor, which is robust against variations of primary and secondary resistances. Conventional field-oriented control originally is robust against the variation of the primary resistance, but has very high parameter sensitivity of the secondary resistance. To compensate for its effect, considerable research has been conducted by using a stator voltage model, a low-sensitivity flux observer, an adaptive system, and so on. It is assumed that successful results have not been made in practice because each method requires not only complicated configurations but also motor parameters. Therefore its compensation has to be carried out with no relation to the motor parameter, especially the primary resistance. In this paper, a robust parameter-identification technique is applied to a field-oriented control system with a flux simulator as a means to solve the problem. The technique is based on instantaneous reactive power which is never affected by the primary resistance. The authors describe the aforementioned control theory and practical implementation. As a result, excellence performance was confirmed by some computer simulations and experimental tests. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 118 (2): 30–40, 1997