Starting Parameters And Performance Calculation Of The Canned Solid-rotor Motor With Squirrel-cage

With the growing demand for transporting liquid,the canned motor,which has low noise and good tightness,is widely used in chemical,defense,petroleum,aerospace and medical industries.Since the canned solid-rotor motor with squirrel-cage has higher reliability,it is more popular in some special applications.Based on previous studies,this paper improves the analytic method of calculating circuit parameters to make it suitable for calculating the performance of this motor with different speeds.And the accuracy is improved,too.The improved method makes the design and analysis of this motor easier.First of all,based on the equivalent circuits in previous studies,a two-dimensional multilayer model is established.The model takes the influence of rotor core saturation and skin effect on the circuit parameters into account.Based on the distribution of magnetic field in locked rotor condition and the structural characteristics,some reasonable assumptions are made and the calculation method of rotor's circuit parameters is improved.Besides,considering the effect of stator can and solid rotor on circuit parameters of motor with different speeds,the stator's impedance and excitation reactance are also modified.Secondly,this paper uses quasi-stability method to calculation starting performance because of the characteristics of pumps.The cyclic calculation method of equivalent circuit parameters is presented and the calculation program is developed.At last,a finite element model of the experimental prototype is established.By comparing the result of finite element method,modified coefficient method,improved method and experiment,the improved method has high accuracy.The cause of error is analyzed by freezing permeability method and freezing conductivity method.In order to confirm the applicable scope of the program,the starting performance of motors with different types of stator slot and numbers of poles are calculated.