Numerical-field analysis of power actions in a three-phase induction motor in statics and dynamics

Представлены принципы и результаты численно-полевого расчета координатных распределений и временных функций силовых действий электромагнитного характера в активной зоне трехфазного асинхронного двигателя в режиме нагрузки. На примере двигателя мощностью 15 кВт анализируются распределение сил по пазам статора и ротора, по зубцам статора, а также динамика изменения этих сил и еще сил радиального стягивания сердечника статора и электромагнитного момента взаимодействия статора и ротора.Presentation of the principles and results of numerical-field calculation of the coordinate and temporal functions of power actions of an electromagnetic nature in the active zone of a three-phase induction motor (TIM) under load conditions. Methodology. Calculations of magnetic fields are carried out with the finite elements method by the FEMM program. The calculations are automated by controlling the operation of the program by means of the scripts created in Lua language. Coordinate functions are obtained by a one-time calculation in a statics, temporal functions – in dynamics by multi-position calculations of rotating magnetic fields within the full rotation of the rotor. Results. Test calculations are carried out on a 15 kW TIM. The distribution of forces along the stator and rotor grooves, along the stator teeth, as well as the dynamics of the changes of these forces and also the forces of radial contraction of the stator core and of the electromagnetic moment of the stator and rotor interaction are analyzed. Originality. The updated principles of forming the design model of TIM are presented on the basis of design data with the original formation of the current structure in the rotor grooves, as well as the author's principles for organizing multi-position calculations of the rotating magnetic fields of TIM in dynamics. Unique temporal functions of forces acting on individual elements of the electromagnetic system of TIM are obtained. Practical value. Numerical-field analysis of the coordinate functions of the forces acting in the TIM allowed to reveal aspects that were previously unavailable when using classical methods for calculating the TIM magnetic circuit. The results showed that when they are taken into account, the TIM design process has reserves of refinement in terms of ensuring its mechanical reliability and durability