水轮发电机碳刷/集电环界面间隙放电试验研究

Experimental Study on Gap Discharge Between Carbon Brush/Slip Ring Interface of Hydro-generator

水轮发电机集电环运行过程中出现的偏心摆振会使碳刷/集电环界面接触时产生瞬时间隙,这会导致界面放电出现碳刷打火烧蚀的现象。通过多组界面间隙放电试验,以高速相机拍摄电火花貌,利用python对图片提取电火花面积取平均值表征放电相对强度。结果表明,界面放电相对强度随间隙的变化先增后减,呈偏正态分布;放电特点与极性相关,碳刷接负极放电位置偏离中心呈球/椭球状,强度较大;碳刷接正极放电位于中心部位呈柱状,强度较小。

The eccentric vibration during the operation of the collector ring of the hydro-generator will cause an instantaneous gap when the carbon brush/collector ring interface is in contact.Through multiple groups of interface gap discharge tests,high-speed camera was used to capture the appearance of the electric spark,and python was used to extract the area of the electric spark from the picture and take the average value to characterize the relative intensity of the discharge.It is found that the relative intensity of interfacial discharge increases first and then decreases with the change of the gap,showing a skewed normal distribution.The discharge characteristics are related to the polarity.The discharge position of the carbon brush connected to the negative electrode deviates from the center and is spherical/ellipsoidal,with high intensity;The carbon brush connected to the positive electrode is located in the center and is columnar,with low intensity.