Design And Performance Analysis Of Five-phase Asynchronous Motor

The model of a three-phase asynchronous motor was Y160L-4 and the power was 15 kW,and a five-phase asynchronous motor was designed based on the fact that the inner and outer diameters of the stator and rotor of the three-phase asynchronous motor were unchanged and the power was constant.Then the performance comparison between the five-phase asynchronous motor and the three-phase asynchronous motor was analyzed.The specific research contents were as follows:First,The characteristics and advantages of the five-phase windings were introduced.The five-phase windings were designed using the space-time phase coincidence method and the slot electromotive force star diagram method.The harmonic-to-leakage magnetic permeability equation was deduced,the basic size of a prototype motor was determined according to the asynchronous motor design method and the modifier formula.The equivalent circuit,no-load magnetic field and mechanical characteristics of the five-phase asynchronous motor were analyzed,and the correctness and rationality of the design of the five-phase asynchronous motor was verified.The comparison showed that the starting characteristics,efficiency and effective material cost of the five-phase asynchronous motor were better than those of the three-phase asynchronous motor.Secondly,the basic mathematical model of five-phase asynchronous motor was analyzed,and the space decomposition mathematical model for five-phase induction motor was established from the perspective of the space decomposition transformation theory.In order to study the harmonic magnetic motive force of five-phase asynchronous motor,the magnetic motive force expression of multiple symmetrical windings was derived,and the distribution regularity of harmonic magnetic motive force in five-phase winding and three-phase winding was revealed.On the basis of magnetic motive force,the causes and characteristics of harmonictorque generation were analyzed in detail from two angles.Finally,the performance of five-phase asynchronous motor and three-phase asynchronous motor under fault operation conditions were compared and analyzed.In the first place,the generalized symmetrical component method and each order equivalent circuit were introduced.The correctness of the finite element method was verified by the generalized symmetry component method.According to the finite element method,the torque ripple,the copper loss of the stator and rotor and the iron loss of the five-phase asynchronous motor were better than those of the three-phase asynchronous motor,when the powers were unbalanced and two motors were operation out of phase.The field-circuit coupling model of the five-phase asynchronous motor was established.According to the field-circuit coupling method,the total loss of the five-phase asynchronous motor was smaller and the average electromagnetic torque was larger when the two motors were short-circuited.Compared with the air gap magnetic density waveform distribution when the two motors were in normal operation,the air gap magnetic density waveform distribution variation of the five-phase asynchronous motor was smaller when the five-phase asynchronous motor and the three-phase asynchronous motor were short-circuited.