针对架空配电线路电弧接地故障点定位难题,该文研究架空配电线路故障电弧的电磁辐射特性,探索基于电磁辐射信号的电弧故障定位方法的可行性。通过10 k V配网真型故障模拟试验平台,分析接地电弧电磁辐射的时域与频域特性及传播衰减规律,...针对架空配电线路电弧接地故障点定位难题,该文研究架空配电线路故障电弧的电磁辐射特性,探索基于电磁辐射信号的电弧故障定位方法的可行性。通过10 k V配网真型故障模拟试验平台,分析接地电弧电磁辐射的时域与频域特性及传播衰减规律,结果表明:电弧电流的电磁辐射特征频段为20~30 MHz,该特征频段不会受到中性点接地方式、电弧接地介质与线路结构参数的显著影响,且特征频段内辐射信号在传播过程中衰减较慢。在此基础上,设计一种小型化三角形单极子–环形组合平面天线,工作频率为20~500 MHz。利用自制天线开展小型电弧故障定位实验,为后续配网电弧故障定位的应用研究提供基础。展开更多
Characteristic analysis of transient electromagnetic disturbance data is very important. In this paper, the time-domain and frequency-domain characteristics of transient electromagnetic disturbance caused by switching...Characteristic analysis of transient electromagnetic disturbance data is very important. In this paper, the time-domain and frequency-domain characteristics of transient electromagnetic disturbance caused by switching operations in substations are analyzed. Two methods are adopted in time-domain analysis. One method is histogram and the other one is normality test. An appropriate procedure for the normality test is proposed. Furthermore, the method used in frequency- domain analysis is to obtain overall envelope. These statistical characteristic analysis methods are showed to be of great value in analyses of the measured samples. The simulation results showed that these methods are effective.展开更多
针对风电机组滚动轴承工作环境恶劣、工况多变且振动信号成分复杂等特点,将33项时域和频域特征参数及其特性应用于风电机组滚动轴承状态监测和故障诊断中,利用奇异值分解重构法(Singular Value Decomposition,SVD)将滚动轴承振动故障信...针对风电机组滚动轴承工作环境恶劣、工况多变且振动信号成分复杂等特点,将33项时域和频域特征参数及其特性应用于风电机组滚动轴承状态监测和故障诊断中,利用奇异值分解重构法(Singular Value Decomposition,SVD)将滚动轴承振动故障信号中的噪声等干扰成分去除,降噪重构后的信号经过基于经验模式分解法(Empirical Mode Decomposition,EMD)的希尔伯特-黄变换,实现故障冲击信号的共振解调处理,将低频周期故障调制信号筛选出来,最终结合滚动轴承各部件故障特征频率、振动信号时频分析结果和时频特征参数诊断结果实现滚动轴承的状态监测和故障识别。并通过振动测试信号分析,验证了该方法对提取风电机组滚动轴承故障特征的有效性。展开更多
文摘针对架空配电线路电弧接地故障点定位难题,该文研究架空配电线路故障电弧的电磁辐射特性,探索基于电磁辐射信号的电弧故障定位方法的可行性。通过10 k V配网真型故障模拟试验平台,分析接地电弧电磁辐射的时域与频域特性及传播衰减规律,结果表明:电弧电流的电磁辐射特征频段为20~30 MHz,该特征频段不会受到中性点接地方式、电弧接地介质与线路结构参数的显著影响,且特征频段内辐射信号在传播过程中衰减较慢。在此基础上,设计一种小型化三角形单极子–环形组合平面天线,工作频率为20~500 MHz。利用自制天线开展小型电弧故障定位实验,为后续配网电弧故障定位的应用研究提供基础。
文摘Characteristic analysis of transient electromagnetic disturbance data is very important. In this paper, the time-domain and frequency-domain characteristics of transient electromagnetic disturbance caused by switching operations in substations are analyzed. Two methods are adopted in time-domain analysis. One method is histogram and the other one is normality test. An appropriate procedure for the normality test is proposed. Furthermore, the method used in frequency- domain analysis is to obtain overall envelope. These statistical characteristic analysis methods are showed to be of great value in analyses of the measured samples. The simulation results showed that these methods are effective.
文摘针对风电机组滚动轴承工作环境恶劣、工况多变且振动信号成分复杂等特点,将33项时域和频域特征参数及其特性应用于风电机组滚动轴承状态监测和故障诊断中,利用奇异值分解重构法(Singular Value Decomposition,SVD)将滚动轴承振动故障信号中的噪声等干扰成分去除,降噪重构后的信号经过基于经验模式分解法(Empirical Mode Decomposition,EMD)的希尔伯特-黄变换,实现故障冲击信号的共振解调处理,将低频周期故障调制信号筛选出来,最终结合滚动轴承各部件故障特征频率、振动信号时频分析结果和时频特征参数诊断结果实现滚动轴承的状态监测和故障识别。并通过振动测试信号分析,验证了该方法对提取风电机组滚动轴承故障特征的有效性。
