Proposition of new mathematical models with core loss factor for controlling AC motors

This paper establishes in a new unified manner new mathematical models with core (iron) loss factor for two kinds of AC motors, induction and synchronous motors which are supposed to generate torque precisely or/and efficiently under vector controls. Our new models consist of three basic equations consistent with the others such as differential equation describing electromagnetic dynamics, torque equation describing torque generating mechanism, energy transmission equation describing how injected energy is wasted, saved or transmitted where all vector signals are defined in a general frame of arbitrary instant angular velocity. It is clearly shown in our models that equivalent core-loss resistance can express appropriately and separately both eddy-current and hysteresis losses rather than mere vague loss. The proposed model of the induction motor is the most compact in sense of the number of employed interior states and parameters. This compact model can also represent eddy-current and hysteresis losses of the rotor as well as the stator. For the synchronous motor, saliency is taken into consideration. A model for a cylindrical motor can be obtained directly from the salient one as a special case.