The problems associated with vibrations of viaducts and low-frequency structural noise radiation caused by train excitation continue to increase in importance.A new floating-slab track vibration isolator-non-obstructi...The problems associated with vibrations of viaducts and low-frequency structural noise radiation caused by train excitation continue to increase in importance.A new floating-slab track vibration isolator-non-obstructive particle damping-phononic crystal vibration isolator is proposed herein,which uses the particle damping vibration absorption technology and bandgap vibration control theory.The vibration reduction performance of the NOPD-PCVI was analyzed from the perspective of vibration control.The paper explores the structure-borne noise reduction performance of the NOPD-PCVIs installed on different bridge structures under varying service conditions encountered in practical engineering applications.The load transferred to the bridge is obtained from a coupled train-FST-bridge analytical model considering the different structural parameters of bridges.The vibration responses are obtained using the finite element method,while the structural noise radiation is simulated using the frequency-domain boundary element method.Using the particle swarm optimization algorithm,the parameters of the NOPD-PCVI are optimized so that its frequency bandgap matches the dominant bridge structural noise frequency range.The noise reduction performance of the NOPD-PCVIs is compared to the steel-spring isolation under different service conditions.展开更多
The use of non-power frequency components for protection measurements in an area that has received relatively little attention. Although work on the use of switched stack tuners has been reported for fault detection, ...The use of non-power frequency components for protection measurements in an area that has received relatively little attention. Although work on the use of switched stack tuners has been reported for fault detection, the sensitivity of switched arrangements is limited by scnsitivity of directional detectors for switching purposes. This paper presents an alternative non-switching scheme which is relatively simple.A simplified typical 400kV system with the line trap, stack tuner, coupling capacitor and bus capacitance to earth is considered. Fault studies by using the EMTP have been carried out, frequency-dependent pararnctcrs are used for the line representation. Arcing faults have also bccn investigated and the results show a great promise of the scheme.展开更多
Audible noise from high voltage transmission lines’ corona discharge has become one of the decisive factors affecting design of high voltage transmission lines, thus it is very important to study the spatial propagat...Audible noise from high voltage transmission lines’ corona discharge has become one of the decisive factors affecting design of high voltage transmission lines, thus it is very important to study the spatial propagation characteristics of audible noise for its accurate pre- diction. A calculation model for the propagation of audible noise is presented in this paper, which is based on the basic equation of the sound wave and can involve the influences of the atmosphere absorption and ground effects. The effects of different ground impedances and the atmospheric attenuation on the distribution of sound pressure level are discussed in this paper. The results show that the atmospheric absorp- tion may increase the attenuation of the audible noise, and the ground surface affects both the amplitude and phase of the sound. The spatial distribution fluctuates considering the ground effects. The atmospheric attenuation and the ground effect are closely related to the frequency of the noise. In the frequency range of the audible noise, the influence of atmospheric attenuation on the spatial propagation characteristics is more obvious in high frequency while ground has significant influences in low frequency.展开更多
为了研究考虑高海拔多环境因素影响下输电线路可听噪声的预测问题,在海拔2400 m高度点的500 kV同塔双回线路下,搭建了边相外20、30、35 m三处可听噪声观测站,同时利用气象站进行多环境因素指标的数据采集。文中提出了一种基于多头注意...为了研究考虑高海拔多环境因素影响下输电线路可听噪声的预测问题,在海拔2400 m高度点的500 kV同塔双回线路下,搭建了边相外20、30、35 m三处可听噪声观测站,同时利用气象站进行多环境因素指标的数据采集。文中提出了一种基于多头注意力机制(multi⁃head attention,MHA)的卷积神经网络(convolutional neural network,CNN)—双向长短期记忆网络(bi⁃directional long short term memory,BiLSTM)模型进行可听噪声预测。首先,采用皮尔逊相关性分析对多种环境因素数据进行相关程度计算比较与剔除;然后,为充分挖掘可听噪声数据中的时序特征,使用CNN对多环境因素数据进行特征提取;再将提取的特征向量输入到BiLSTM中进行训练,并通过在BiLSTM端引入多头注意力机制,使模型学习权重更高的数据特征,从而提升模型预测精度;结果表明,该方法构建的组合模型可以提升考虑多因素特征可听噪声数据的预测精度,且具有较好的泛化性。展开更多
基金Project(51978585)supported by the National Natural Science Foundation,ChinaProject(2022YFB2603404)supported by the National Key Research and Development Program,China+1 种基金Project(U1734207)supported by the High-speed Rail Joint Fund Key Projects of Basic Research,ChinaProject(2023NSFSC1975)supported by the Sichuan Nature and Science Foundation Innovation Research Group Project,China。
文摘The problems associated with vibrations of viaducts and low-frequency structural noise radiation caused by train excitation continue to increase in importance.A new floating-slab track vibration isolator-non-obstructive particle damping-phononic crystal vibration isolator is proposed herein,which uses the particle damping vibration absorption technology and bandgap vibration control theory.The vibration reduction performance of the NOPD-PCVI was analyzed from the perspective of vibration control.The paper explores the structure-borne noise reduction performance of the NOPD-PCVIs installed on different bridge structures under varying service conditions encountered in practical engineering applications.The load transferred to the bridge is obtained from a coupled train-FST-bridge analytical model considering the different structural parameters of bridges.The vibration responses are obtained using the finite element method,while the structural noise radiation is simulated using the frequency-domain boundary element method.Using the particle swarm optimization algorithm,the parameters of the NOPD-PCVI are optimized so that its frequency bandgap matches the dominant bridge structural noise frequency range.The noise reduction performance of the NOPD-PCVIs is compared to the steel-spring isolation under different service conditions.
文摘The use of non-power frequency components for protection measurements in an area that has received relatively little attention. Although work on the use of switched stack tuners has been reported for fault detection, the sensitivity of switched arrangements is limited by scnsitivity of directional detectors for switching purposes. This paper presents an alternative non-switching scheme which is relatively simple.A simplified typical 400kV system with the line trap, stack tuner, coupling capacitor and bus capacitance to earth is considered. Fault studies by using the EMTP have been carried out, frequency-dependent pararnctcrs are used for the line representation. Arcing faults have also bccn investigated and the results show a great promise of the scheme.
基金Project supported by National Basic Research Program of China (973 Program) (2011 CB209402)Fundamental Research Funds for the Central Universities(13XS07)
文摘Audible noise from high voltage transmission lines’ corona discharge has become one of the decisive factors affecting design of high voltage transmission lines, thus it is very important to study the spatial propagation characteristics of audible noise for its accurate pre- diction. A calculation model for the propagation of audible noise is presented in this paper, which is based on the basic equation of the sound wave and can involve the influences of the atmosphere absorption and ground effects. The effects of different ground impedances and the atmospheric attenuation on the distribution of sound pressure level are discussed in this paper. The results show that the atmospheric absorp- tion may increase the attenuation of the audible noise, and the ground surface affects both the amplitude and phase of the sound. The spatial distribution fluctuates considering the ground effects. The atmospheric attenuation and the ground effect are closely related to the frequency of the noise. In the frequency range of the audible noise, the influence of atmospheric attenuation on the spatial propagation characteristics is more obvious in high frequency while ground has significant influences in low frequency.
基金Supported by National Research Foundation of Singapore （NRF-CRP8-2011-03） and National Natural Science Foundation of China （61120106011, 61034007, 61203045, 61304045）
文摘为了研究考虑高海拔多环境因素影响下输电线路可听噪声的预测问题,在海拔2400 m高度点的500 kV同塔双回线路下,搭建了边相外20、30、35 m三处可听噪声观测站,同时利用气象站进行多环境因素指标的数据采集。文中提出了一种基于多头注意力机制(multi⁃head attention,MHA)的卷积神经网络(convolutional neural network,CNN)—双向长短期记忆网络(bi⁃directional long short term memory,BiLSTM)模型进行可听噪声预测。首先,采用皮尔逊相关性分析对多种环境因素数据进行相关程度计算比较与剔除;然后,为充分挖掘可听噪声数据中的时序特征,使用CNN对多环境因素数据进行特征提取;再将提取的特征向量输入到BiLSTM中进行训练,并通过在BiLSTM端引入多头注意力机制,使模型学习权重更高的数据特征,从而提升模型预测精度;结果表明,该方法构建的组合模型可以提升考虑多因素特征可听噪声数据的预测精度,且具有较好的泛化性。
