大电流开关柜温度分布特性的影响因素分析  

Analysis of influencing factors on temperature distribution characteristics of high current switchgear

作　　者：李江涛[1] 孙义 李擎宇 董宁 赵政[1] Li Jiangtao;Sun Yi;Li Qingyu;Dong Ning;Zhao Zheng(School of Electrical Engineering,Xi＇an Jiaotong University,Xi＇an 710049)

机构地区：[1]西安交通大学电气工程学院,西安710049

出　　处：《电气技术》2018年第9期12-18,共7页Electrical Engineering

摘　　要：负荷电流、环境温度、接触电阻是影响大电流开关柜温升的重要因素。本文针对4000A大电流开关柜建立仿真建模,利用COMSOL进行电磁-传热-对流多物理场耦合仿真计算,归纳了4000A大电流开关柜内部温度分布规律;研究了负荷电流、环境温度以及开关柜各部位接触电阻的增加对于母线和梅花触头温升的影响情况。本设计并进行了大电流开关柜不同负荷条件下稳态温升实验,实验结果验证了仿真模型的合理性。经计算得出,对于4000A大电流开关柜,在负荷达到约80%时,梅花触头温升已超出国标上限,需要对开关柜进行强制散热。环境温度对开关柜内部温升有较大的影响,在设计开关柜温升监测系统时不能忽视环境温度的监测。梅花触头与静触头搭接点接触电阻的增加较大程度影响梅花触头和母线的温升,因此需要对梅花触头的温升实时监测以确保及时发现异常运行状态。电流互感器是大电流开关柜中不可忽略的发热部位,若安装不当存在接触问题,则会产生异常温升影响整体母线温度分布。本文研究结果可为后续开展开关柜温升在线监测、故障位置判断以及设计运维方案提供一定的理论依据。Load current, ambient temperature, contact resistance is an important factor affecting the temperature of high current switchgear. In this paper, the electromagnetic-heat transfer-convection multi-physics coupled simulation model is established by COMSOL to calculate the internal temperature distribution of 4000A high current switchgear. The influence of load current, ambient temperature and contact resistance on the temperature rise of tulip contact and bus bars were studied. The steady state temperature rise experiment of high current switchgear under different load conditions is designed and carried out. The experimental results verify the rationality of the simulation model. The results showed that the temperature rise of tulip contact has exceeded the upper limit at about 80% load current and the forced heat dissipation of switchgear is required. The ambient temperature has a great influence on the temperature rise inside the switchgear. The monitoring of the ambient temperature is necessary in designing the switchgear temperature monitoring system. The increase of contact resistance of contact points has a great influence on the temperature rise of tulip contacts and bus bars. The temperature rise of contacts should be monitored in real time so as to find the abnormal running state. The temperature rise of current transformer in high current switchgear is an important index needed to be considered in the temperature monitor system. The improper installation of current transformer leads to a severe temperature rise of bus bars. The results may provide a theoretical basis for the follow-up to determine the fault location of on-line switchgear temperature monitoring and the design of operation and maintenance plan.

关 键 词：大电流开关柜 多物理场仿真 温升实验 接触电阻 温度分布 

分 类 号：TM591[电气工程—电器]