Statistical method for analyzing shaft orbit of hydro-generator
Fu Jing1, Zhang Fei2, Li Bing1
1.Department of Integrated Service, China Institute of Water Resources and Hydropower Engineering, Beijing 100038, China; 2.Department of Hydraulic Machinery, China Institute of Water Resources and Hydropower Engineering, Beijing 100038, China
Abstract：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.
[1]罗开玉,李伯全,王小飞,等. 基于虚拟仪器的机械转子轴心轨迹分析[J]. 江苏大学学报:自然科学版, 2008,29(6):474-477. Luo Kaiyu, Li Boquan, Wang Xiaofei, et al. Study on mechanical rotor axis locus based on virtual instrument[J]. Journal of Jiangsu University: Natural Science Edition, 2008,29(6):474-477.(in Chinese)[2]沙盛中,翁桂荣.基于数学形态学的轴心轨迹滤波提纯法[J].苏州大学学报:工科版,2007,27(4):39-41. Sha Shengzhong, Weng Guirong. Purification of shaft orbit with mathematical morphology filters[J]. Journal of Suzhou University: Engineering Science Edition, 2007,27(4):39-41.(in Chinese)[3]钱玉良,张浩,彭道刚,等.基于新的广义粒子群方法的水电机组轴心轨迹提纯[J].中国电机工程学报,2012,32(2):130-137. Qian Yuliang, Zhang Hao, Peng Daogang, et al. Orbit purification of generator unit based on a new generalized particle swarm optimization method[J]. Proceeding of the CSEE, 2012,32(2):130-137.(in Chinese)[4]李方,李友荣,王志刚.应用广义谐波提纯转子轴心轨迹[J].振动、测试与诊断, 2008,28(1):55-57. Li Fang, Li Yourong, Wang Zhigang. Shaft orbit purification based on generalized harmonics[J]. Journal of Vibration, Measurement and Diagnosis, 2008,28(1):55-57.(in Chinese)[5]翁桂荣,薛峰. 几种特征描述方法在轴心轨迹识别中的应用[J]. 振动、测试与诊断, 2007,27(4):296-299. Weng Guirong, Xue Feng. Application of characteristic description method on shaft orbit recognization[J]. Journal of Vibration, Measurement and Diagnosis, 2007,27(4): 296-299.(in Chinese)[6]张征凯,薛松,张优云. 基于特征参数的旋转机械智能故障诊断方法[J]. 振动、测试与诊断, 2009,29(3):256-260. Zhang Zhengkai, Xue Song, Zhang Youyun. Intellectual diagnosis method study on rotating machines based on characteristic parameters[J]. Journal of Vibration, Measurement and Diagnosis, 2009,29(3):256-260.(in Chinese)[7]陈喜阳,张克危. 一种新矩在水电机组周欣轨迹识别中的应用[J]. 华中科技大学学报: 自然科学版, 2006,34(3):79-81. Cheng Xiyang, Zhang Kewei. Application of a new moment invariant to identification of axis orbit in hydro-ge-nerator unit[J]. Journal of Huazhong University of Science & Technology: Nature Science Edition, 2006,34(3):79-81.(in Chinese)[8]许云飞,钟秉林,黄仁. 轴心轨迹自动识别及其在旋转机诊断中的应用[J]. 振动、测试与诊断, 2009,29(2):141-145. Xu Yunfei, Zhong Binglin, Huang Ren. Shaft orbit automatic reorganization on rotational machine diagnosis[J]. Journal of Vibration, Measurement and Diagnosis, 2009,29(2):141-145.(in Chinese)[9]张大明,金涛,秦树人. 智能控件化虚拟式轴心轨迹分析系统[J]. 重庆大学学报:自然科学版,2005,28(3):7-10. Zhang Daming, Jin Tao, Qin Shuren. Intelligent control oriented virtual axis locus analyzing system[J]. Journal of Chongqing University: Natural Science Edition, 2005, 28(3):7-10.(in Chinese)[10]李洁明,祁新娥. 统计学原理[M].5版.上海:复旦大学出版社, 2012.[11]IEC 60041Field acceptance tests to determine the hydraulic performance of hydraulic turbines, storage pumps and pump-turbines[S]. 3rd ed. 1991.[12]GB/T 20043—2005水轮机、蓄能泵和水泵水轮机水力性能现场验收试验规程[S].[13]International Organization for Standardization. ISO 7919-5:2005Mechanical vibration—Evaluation of machine vibration by measurements on rotating shafts—Part 5: Machine sets in hydraulic power generating and pumping plants[S].
