水力脉动下抽水蓄能机组扭振特性辨识方法  

Identification Method of Torsional Vibration Characteristics of Pumped Storage Units Under Hydraulic Pulsation

作　　者：马运翔[1] 刘晓锋[1] 何小锋[1] 彭辉[1] 曹扬 MA Yunxiang;LIU Xiaofeng;HE Xiaofeng;PENG Hui;CAO Yang(Jiangsu Frontier Electric Technology Co.,Ltd.,Nanjing 211102,China)

机构地区：[1]江苏方天电力技术有限公司,南京211102

出　　处：《动力工程学报》2024年第6期859-864,共6页Journal of Chinese Society of Power Engineering

基　　金：江苏方天电力技术有限公司科技资助项目(KJ202102)。

摘　　要：提出一种基于水力脉动的抽水蓄能机组轴系扭振特性辨识方法,即采用应变测试技术获取随机性动态扭矩信号;设置触发阈值,将扭矩信号和阈值的交点及其后一定长度的样本点组成样本信号;对足够多样本平均后,信号中随机响应和正/负速度冲击响应被平均掉,剩余则为幅值冲击响应信号;用指数函数拟合冲击响应信号,从中得到扭振固有频率和阻尼。将该方法应用于某抽水蓄能机组扭振特性辨识。试验结果表明:25%负荷工况下水力脉动幅度较大,触发阈值对阻尼和频率辨识结果的影响较小;负荷升高后扭矩脉动幅度减小,触发阈值对频率识别值的影响较小,但会影响阻尼识别值;该方法无需施加扭矩激励,可以实现安装状态下扭振特性辨识,具有较强的工程应用价值。A torsional vibration identification method for shafting of pumped storage unit based on hydraulic pulsation was proposed.The dynamic random torque signal was obtained by using strain measurement technology.Setting the trigger threshold,a group of sample signals was obtained by using the intersection point of the signal,the threshold and the points of a certain length.After averaging a sufficient number of sampled signals,the random response and positive/negative velocity impact response were averaged out,and the remaining signal was the amplitude impact response signal.The torsional natural frequency and damping could be obtained by fitting the impact response signal with exponential function.The method was applied to identify the torsional characteristics of a pumped storage unit.The test results show that the hydraulic fluctuation is larger under 25%load condition.The trigger threshold has little influence on the identification results.When the load increases,the torque pulsation decreases.The trigger threshold has little effect on the identified frequency,but it will affect the identified damping.This method does not need to apply torque excitation.It realizes the identification of torsional vibration characteristics under installation conditions,which has a good engineering application value.

关 键 词：水轮机 抽水蓄能 扭振 固有频率 阻尼 

分 类 号：TK730.7[交通运输工程—轮机工程]