基于统计分析方法的水轮发电机组轴心轨迹

针对目前水轮发电机组轴心轨迹分析方法单一、不能对轴系运行状态进行长期有效监测的问题,采用统计分析手段,定义了轴心轨迹的标准差、变异系数、面积和归一化面积,采用这些参数对某电站指定水头下不同负荷工况的轴心轨迹进行了研究.实例分析表明,定义的轴心轨迹标准差与变异系数能够描述轴心轨迹的清晰程度;变异系数可以表征不同工况下水力因素对轴心轨迹的影响;相同工况下,不同位置的轴心轨迹归一化面积具有相同量级且一致的变化趋势,从而使得归一化面积能够消除测点部位、轴瓦间隙调整等方面的影响,以获得对不同部位轴心轨迹的通用评价;采用轴心轨迹的标准差和归一化面积能够准确评价机组因工况变化而导致的轴心轨迹差异并反映机组的运行状态,从而解决轴心轨迹在线监测手段缺乏的问题.

Statistical method for analyzing shaft orbit of hydro-generator

Because the methods for analyzing the shaft orbit of hydro-generator are very less presently, the shaft orbit cannot be monitored effectively in a long period of time in operation. In the paper, a few parameters, namely standard deviation, coefficient of variation, area and normalized area are defined for the shaft orbit based on statistic method, then the shaft orbits of the hydro-generator in a hydro-power plant were studied under various operational conditions at a fixed head by the parameters. It was shown that the clarity of shaft orbit can be described by the defined standard deviation and coefficient of variation. The influence of hydraulic parameters under various operational conditions on shaft orbit can be indicated by the coefficient of variation.Under the same working condition,the normalized areas measured at different locations have the same order and identical trend, so that effects of monitoring locations and bearing clearance adjustment etc on the orbit have been eliminated, eventually a general assessment of the shaft orbit can be made. The standard deviation and normalized area are sensitive to change in the shaft orbit caused from the variable operating conditions of a hydro-generator unit, thus they can be used in shaft orbit on-line monitoring of a hydro-generator unit.