STUDY ON MAGNETIC FIELD ANALYSIS FOR DEVELOPING HIGHLY EFFICIENCY MOTORS CONSIDERING RESIDUAL STRESS AND ROTATING FIELD

用单片测试仪（SST）测量了在外加应力和旋转磁通作用下的磁特性。探讨了将这些数据应用于电机磁场分析的方法。实验结果如下：1.测量系统的建立和测量精度的检验建立了数字测量系统，研究了相位误差和增益特性对测量精度的影响。2.应力加载和旋转磁通下磁特性的测量了加载到70 Mpa左右时的磁特性。测量了实际电机在椭圆长短轴及谐波分量的各种组合下的旋转磁通铁损，并建立了数值分析的数据库。3.热装下的磁特性测量采用特殊的H线圈和改进的探针法测量了铝环热装下环形铁芯的微观磁特性。4.温度对钢的磁特性的影响通过在烘箱中设置SST来测量磁特性随温度的变化。结果表明，铁损随温度的升高而减小，低钢级磁滞损耗的减小幅度较大。5.电机验证模型的铁损分析及实验研究考虑残余应力和旋转磁场下的磁性能，采用有限元法对电机验证模型的铁损进行了分析。通过与实测值的比较，对铁损分析中存在的问题进行了探讨。

The magnetic characteristics when the stress is impressed and under rotating flux are measured using single sheet testers(SST). The method for applying these data to the analysis of magnetic field of motor is investigated. The results obtained are summarized as follows :1.Establishment of Measuring System and Examination of Measurement AccuracyA digital measuring system is established, and the effect of the phase error and characteristics of gain on the measurement accuracy is examined.2.Measurement of Magnetic Characteristics Under Stress Impressed Condition and Rotating FluxThe magnetic characteristics when until about 70 Mpa is impressed are measured. The iron losses due to rotating flux, under various combinations of long and short axes of ellipse and harmonic components which are observed in the actual motors, are measured and the data base for the numerical analysis is constructed.3.Measurement of Magnetic Characteristics Under Shrink FittingThe microscopic magnetic characteristics of ring core under shrink fitting of aluminum ring are measured using a special H coil and a modified probe method. The local magnetic characteristics are examined.4.Effect of Temperature on Magnetic Characteristics of SteelThe change of magnetic characteristics with the temperature is measured by setting SST in an oven. It is shown that the iron loss is reduced with the temperature, and the rate of decrease of hysteresis loss of low grade steel is remarkable.5.Analysis of Iron Loss of Verification Model of Motor and Experimental InvestigationThe iron loss of verification motor model is analyzed using FEM considering the residual stress and magnetic property under rotating field. The problems of the analysis of iron loss is examined by comparing with the measured values.