变流器接地检测电路对电机定子绕组绝缘的影响

Impact on Stator Winding Insulation of Traction Converter Grouding Detection Circuit

在铁路机车与动车上,牵引电机绝缘损坏占电机故障比例最高,根据牵引变流器主回路接地检测原理,本文在分析接地检测电路与电机定子绕组绝缘构成的等效回路基础上,研究了不同的接地电阻分压方案对定子绕组绝缘的影响。从电老化与热老化的角度提出了对定子绕组绝缘寿命影响最小的接地电阻分压方案,并进行了理论验证与试验验证。理论验证和试验验证都证明了本文提出的牵引变流器接地电阻分压方案对牵引电机定子绕组绝缘寿命影响最小,为后续牵引变流器主回路接地检测电路的设计与优化提供了依据。

In railway locomotives and motor vehicles,the insulation damage of traction motor accounts for the highest proportion of motor faults.According to the grounding detection principle of the main circuit of traction converter,based on the analysis of the equivalent circuit composed of grounding detection circuit and stator winding insulation of motor,this paper studies the influence of different grounding resistance voltage division schemes on stator winding insulation.From the perspective of electrical aging and thermal aging,a grounding resistance voltage division scheme with the least influence on the insulation life of stator winding is proposed,and theoretical verification and experimental verification are carried out.Both theoretical verification and experimental verification prove that the grounding resistance voltage division scheme of the traction converter proposed in this paper has the least influence on the insulation life of the stator winding of the traction motor,which provides a basis for the design and optimization of the main circuit grounding detection circuit of the subsequent traction converter.