同步发电机定子铁心磁-热-固耦合计算分析  

Calculation and analysis of electromagnetic-temperature-stress coupling of the stator core of synchronous generator

作　　者：何玉灵[1] 蒋梦雅 邱名豪 HE Yuling;JIANG Mengya;QIU Minghao(North China Electric Power University(Hebei Key Laboratory of Electric Machinery Health Maintainence&Failure Prevention),Baoding 071003,China)

机构地区：[1]华北电力大学(河北省电力机械设备健康维护与失效预防重点实验室),河北保定071003

出　　处：《电力工程技术》2024年第4期208-216,共9页Electric Power Engineering Technology

基　　金：国家自然科学基金资助项目(52177042);河北省自然科学基金资助项目(E2020502032);中央高校基本科研业务费专项基金资助项目(2020MS114,2023MS128)。

摘　　要：为分析发电机运行过程中定子铁心的损耗、温升及其在磁拉力和热应力综合作用下的机械结构响应,文中对同步发电机定子铁心进行磁-热-固多物理场耦合计算。首先,理论推导铁心损耗及其所受的单位面积磁拉力,分析铁心的温升特性,在此基础上解析得到铁心在磁拉力和非均匀热载荷耦合激励下的机械结构响应;然后,构建CS-5型故障模拟发电机作为有限元仿真的三维物理模型,计算得到铁心的单位面积磁拉力、损耗曲线和温度分布情况,并进一步计算获得磁拉力和热载荷同时作用下铁心的变形、应变和应力。结果表明:发电机在稳定运行后,定子齿槽温度最高;槽口处变形量最大,槽底应力较高。最后,通过热电偶和温度巡检仪对CS-5型故障模拟发电机在实际运行过程中的定子铁心端面、槽内和外圆表面的温升进行实时监测,实测的定子铁心温度场分布和有限元仿真结果相吻合,验证了磁-热-固多物理场耦合方法的有效性。文中获得了定子铁心的温度分布规律及其在磁-热耦合激励下的机械结构响应分布规律,为发电机结构逆向优化设计及定子铁心变形预防提供了技术参考。In order to analyze the loss,temperature rise and the mechanical structural response under the combined magnetic tension and thermal stress of the stator core,the electromagnetic-temperature-stress coupling calculation for the stator core of a synchronous generator is carried out in this paper.Firstly,the core loss and the magnetic pull per unit area are theoretically deduced,followed by an analysis of the core′s temperature rise characteristics.On this basis,the mechanical structure response of the core under the coupling excitation of magnetic pull and non-uniform thermal load is obtained.Then,a three-dimensional finite element model of the CS-5 synchronous generator is established.This model calculates the magnetic pull per unit area,loss curve and temperature distribution of the stator core.Furthermore,the deformation,strain and stress of the stator core under the simultaneous action of magnetic tension and thermal load are obtained.The results show that the stator slot temperature is highest when the generator runs stably.The deformation at the groove is largest and the stress at the bottom of the groove is higher.Finally,the temperature rises of the end face,inside slot and outside circle of the stator core are monitored in real-time by thermocouples and a temperature monitor.The measured temperature distribution of the stator core is in good agreement with the finite element simulation results,verifying the effectiveness of the electromagnetic-temperature-stress coupling method.In this paper,the temperature distribution of the stator core and the mechanical structural response distribution of the stator core under magnetic and thermal coupling excitation are obtained,providing a technical reference for the reverse optimization design of the generator structure and the prevention of stator core deformation.

关 键 词：同步发电机 定子铁心 损耗 温升 机械结构响应 失效预防 

分 类 号：TM31[电气工程—电机]