Optimization of the Engine Operation Mode at Vector Control

Abstract

Vector control is used to control the torque of the induction motor, it allows to generate the necessary instantaneous values of the spatial current vectors and stator voltage. The paper presents the results of studying the parameters of the asynchronous drive of a technological electric vehicle using various criteria for efficiency optimization. The minimum stator current criterion is studied which is satisfied when the projections of the current spatial vector on the axis of the synchronous reference system are equal. Also, the criterion of minimizing power losses in the motor was studied, and a method for its provision was proposed on the basis of the known experimental data on idling and short circuit, as well as the parameters of the equivalent circuit of the engine. All components of the power loss (in the stator and rotor windings and in the stator magnetic circuit) are expressed as functions of the magnetizing stator current. After that the extremum of their sum is determined. The calculation of energy costs and power losses in the motor at the rated cycle is performed. The proposed method for calculating and setting the magnetizing and transverse currents provides the average motor efficiency which is 3 percent higher than that of the minimum stator current method.