特高压工程用并联电容器单元热稳定性

Thermal Stability Performance of Shunt Capacitor Unit for UHV Project

温度对电容器单元的运行可靠性有重要影响。电容器单元需要通过热稳定性试验来检验其在最严酷运行条件下的最热点温度是否超过允许值。由于最热点温度测量方法缺少研究基础,目前电容器单元热稳定性试验结果的准确度较低。为此以特高压工程用BAM6.56–556–1W型电容器单元为研究对象,利用有限元分析软件,进行了热稳定性计算;同时在电容器单元内部埋设多个光纤光栅温度传感器,测量电容器单元热平衡时的温度分布。研究得到了电容器单元内部最热点的温度和位置,并分析得出内部最热点温度与外壳温度的关系。最后仿真分析了放置方式、结构参数及环境温度对电容器内部温度分布的影响。研究成果可为特高压工程用并联电容器单元提供一种热稳定性最热点温度相对精确而简便的测量方法,同时为电容器的散热设计提供参考。

Temperature has a great influence on the operation reliability of the capacitor unit. Whether the hottest temperature of a capacitor unit under the most severe operating conditions will exceed the allowable value can be verified by thermal stability tests. Due to the lack of research basis on the capacitor hottest spot temperature measurement, the test results of thermal stability of capacitor unit are not accurate enough. Consequently, taking a capacitor unit UHV BAM6.56-556-1W used in the UHV（ultra high voltage） project as the test object, we adopted the finite element analysis software to calculate the thermal stability. At the same time, lots of FBG（fiber bragg grating） sensors were embedded in the capacitor unit to measure the temperature distribution under thermal equilibrium. The temperature value and the position of the hottest spot in the capacitor unit were found out through the research and the relationship between the hot spot temperature and the temperature of the shell was also revealed. Finally, the effects of placement mode, structure parameters and ambient temperature on the temperature distribution of capacitor were analyzed. Research results not only provide a relatively accurate and simple measurement method for the hottest temperature of UHV shunt capacitor unit, but also offer a reference for the design of capacitor＇s heat dissipation.