摘要
碳刷和滑环是发电机励磁系统的重要组成部分。由于滑环和碳刷之间存在摩擦且有励磁电流通过,系统异常时易引起过热,对两者寿命和性能造成严重的影响,甚至危及机组运行安全。碳刷和滑环的温度监测对保障发电机正常运行和及时发现故障具有重要的意义。然而滑环和碳刷摩擦面温度很难采用光纤传感器等直接测量。本文基于有限元分析方法对碳刷系统进行三维温度场分析。根据碳刷系统的运行特性,建立了旋转摩擦生热和系统对流散热作用下的三维温度场模型。在给出基本假设和边界条件的基础上,分析了碳刷后端面温度与摩擦面温度之间的关系,探讨了热对流及环境温度影响,获得了包含热对流和环境温度参数的后端面温度与摩擦面温度关系式,提出由监测碳刷后端面温度外推摩擦面温度的方法。相关研究对实现水力发电机碳刷的在线温度监测及保障机组安全运行具有指导意义。
Carbon brush and slip ring are important components of generator excitation system. As there is friction between slip ring and carbon brush and excitation current passes through, the system is easy to overheat when it is abnormal, which has a serious impact on their life and performance, and even endangers the safety of unit operation. The temperature monitoring of carbon brush and slip ring is of great significance to ensure the normal operation of the generator and detect faults in time. However, it is difficult to directly measure the temperature of slip ring and carbon brush friction surface with optical fiber sensor. In this paper, the threedimensional temperature field of the carbon brush system is analyzed based on the finite element analysis method. According to the operation characteristics of the carbon brush system, a three-dimensional temperature field model is established under the action of rotary friction heat generation and system convection heat dissipation. On the basis of the basic assumptions and boundary conditions, the relationship between the temperature of the rear end surface of the carbon brush and the temperature of the friction surface is analyzed, the effects of thermal convection and environmental temperature are discussed, and the relationship between the temperature of the rear end surface and the temperature of the friction surface, including the parameters of thermal convection and environmental temperature, is obtained. Finally, a method for extrapolating the temperature of the friction surface from the temperature of the rear end surface of the carbon brush is proposed. The relevant research has guiding significance for realizing the online temperature monitoring of the carbon brush of the hydraulic generator and ensuring the safe operation of the unit.
作者
孙杰
邓敏琪
徐方
司金海
陈涛
SUN Jie;DENG Min-qi;XU Fang;SI Jin-hai;CHEN Tao(Fuchunjiang Hydropower Plant of State Grid Xinyuan Group Co.,Ltd.,Tonglu 311504,Zhejiang Province,China;School of Electronic Science and Engineering,Xi'an Jiaotong University,Xi'an 710054,Shaanxi Province,China)
出处
《炭素》
2022年第4期38-46,共9页
Carbon
关键词
碳刷
水力发电机
温度场
有限元分析
摩擦面温度
在线监测
carbon brush
hydro generator
temperature field
finite element analysis
friction surface temperature
online monitoring
