对于电力气体绝缘金属封闭开关设备(gas insulated metal enclosed switchgear and controlgear,GIS)绝缘子沿面放电这类较为常见且严重的局部放电缺陷,目前还没有合适的诊断方法,为此采用振动法进行故障监测和诊断。对采集的GIS振动信...对于电力气体绝缘金属封闭开关设备(gas insulated metal enclosed switchgear and controlgear,GIS)绝缘子沿面放电这类较为常见且严重的局部放电缺陷,目前还没有合适的诊断方法,为此采用振动法进行故障监测和诊断。对采集的GIS振动信号进行小波包分析,发现GIS局部放电的能量主要集中在1.6~6.4kHz频段内;提出用1.6~6.4kHz频段作为特征频段,给出了局部放电特征系数,其定义为1.6~6.4kHz频段的总能量与6.4~12.8kHz频段的总能量的比值;通过观察特征系数的大小,与正常状态下的值进行比较,就可以判断GIS是否发生沿面放电缺陷;并且给出特征系数的阈值范围,对沿面放电严重程度进行划分。研究表明,该方法可以有效诊断GIS沿面放电故障,与其他方法相比,效果比较好。展开更多
Based on a variational asymptotic analytical model, vibration and aeroelastic stability of rotor blades modeled as anisotropic thin-walled closed-section beams are systematically addressed. The analysis is applied to ...Based on a variational asymptotic analytical model, vibration and aeroelastic stability of rotor blades modeled as anisotropic thin-walled closed-section beams are systematically addressed. The analysis is applied to a laminated composite construction of the circumferentially asymmetric stiffness (CAS) that produces bending-twist coupling. The vibration characteristics of composite beam are determined by the Extended Galerkin Method. The unsteady aerodynamic loads and centrifugal force are integrated with the classical aerodynamic model to deal with aeroelastic stability analysis. The influence of some related factors, ply angle, rotating velocity, and wind speed, is investigated. The paper gives methods of eigenvalue analysis and aeroelastic response, and gives the approaches to restrain classical flutter.展开更多
文摘对于电力气体绝缘金属封闭开关设备(gas insulated metal enclosed switchgear and controlgear,GIS)绝缘子沿面放电这类较为常见且严重的局部放电缺陷,目前还没有合适的诊断方法,为此采用振动法进行故障监测和诊断。对采集的GIS振动信号进行小波包分析,发现GIS局部放电的能量主要集中在1.6~6.4kHz频段内;提出用1.6~6.4kHz频段作为特征频段,给出了局部放电特征系数,其定义为1.6~6.4kHz频段的总能量与6.4~12.8kHz频段的总能量的比值;通过观察特征系数的大小,与正常状态下的值进行比较,就可以判断GIS是否发生沿面放电缺陷;并且给出特征系数的阈值范围,对沿面放电严重程度进行划分。研究表明,该方法可以有效诊断GIS沿面放电故障,与其他方法相比,效果比较好。
基金supported by the National Natural Science Foundations of China (Grant No. 10972124)Science & Technology Project of Shandong Provincial Education Department of China (Grant No. J08LB04)+1 种基金Research Project of ‘SUST Spring Bud’ (2009AZZ020)Qunxing Project of SUST (qx101002)
文摘Based on a variational asymptotic analytical model, vibration and aeroelastic stability of rotor blades modeled as anisotropic thin-walled closed-section beams are systematically addressed. The analysis is applied to a laminated composite construction of the circumferentially asymmetric stiffness (CAS) that produces bending-twist coupling. The vibration characteristics of composite beam are determined by the Extended Galerkin Method. The unsteady aerodynamic loads and centrifugal force are integrated with the classical aerodynamic model to deal with aeroelastic stability analysis. The influence of some related factors, ply angle, rotating velocity, and wind speed, is investigated. The paper gives methods of eigenvalue analysis and aeroelastic response, and gives the approaches to restrain classical flutter.
