Magnetic pulse compression(MPC)system has been widely-used for over a few decades as a technique for producing short-duration,high-peak-power pulses reliably.A novel MPC system which does not contain external demagnet...Magnetic pulse compression(MPC)system has been widely-used for over a few decades as a technique for producing short-duration,high-peak-power pulses reliably.A novel MPC system which does not contain external demagnetization circuits,has broadened the application of MPC systems.Improvements for novel MPC systems are presented.To meet the required voltage and compression gain and on considering of the overall system efficiency,two kinds of most popular MPC systems based on the improved MPC topology are designed,which are 2-stage MPC system and 3-stage MPC system,respectively.Based on the improved MPC topology,several kinds of compact pulse generators are built in pulsed power and supply technology laboratory of Institute of Electrical Engineering,Chinese Academy of Sciences.These generators illustrate that the improved MPC topology,together with solid state switches provides an ideal way to generate pulses of around 100 nano-seconds in width,with mid and high voltage of 10 kV to 100 kV,and a high repetition frequency of about 30 kHz.展开更多
A new fault diagnosis method is proposed to effectively extract the fault features of the sound signal of typical faults of ZDJ9 railway point machines.A multi-entropy feature extraction method is proposed by combing ...A new fault diagnosis method is proposed to effectively extract the fault features of the sound signal of typical faults of ZDJ9 railway point machines.A multi-entropy feature extraction method is proposed by combing multi-scale permutation entropy and wavelet packet entropy.Firstly,empirical mode decomposition is performed on sound signals to obtain modal components with different time scales.Then,multi-scale permutation entropy is extracted from these components.Meanwhile,the wavelet packet entropy of the sound signals of these sensitive nodes is obtained by analysing the reconstructed signals of the last layer nodes.Since the multi-scale permutation entropy and the wavelet packet entropy can distinguish the subtle features of the signal,the subtle features of the information among the high-dimensional features,ReliefF is utilized.Finally,a support vector machine(SVM)is used to judge the original sismal can be obtained as the feature vector of the 2DJ9 iway point mnchine in ditterent states,To reduce the redundant fault type of a ZDJ9 rilway point machine.展开更多
基金Project supported by National Natural Science Foundation of China (50907068, 51222701 ), National Basic Research Program of China (973 Program) (2011 CB209402), Opening Project of State Key Laboratory of Electrical Insulation and Power Equipment in Xi'an Jiaotong University (EIPE12204).
文摘Magnetic pulse compression(MPC)system has been widely-used for over a few decades as a technique for producing short-duration,high-peak-power pulses reliably.A novel MPC system which does not contain external demagnetization circuits,has broadened the application of MPC systems.Improvements for novel MPC systems are presented.To meet the required voltage and compression gain and on considering of the overall system efficiency,two kinds of most popular MPC systems based on the improved MPC topology are designed,which are 2-stage MPC system and 3-stage MPC system,respectively.Based on the improved MPC topology,several kinds of compact pulse generators are built in pulsed power and supply technology laboratory of Institute of Electrical Engineering,Chinese Academy of Sciences.These generators illustrate that the improved MPC topology,together with solid state switches provides an ideal way to generate pulses of around 100 nano-seconds in width,with mid and high voltage of 10 kV to 100 kV,and a high repetition frequency of about 30 kHz.
基金supported by the Natural Science Foundation Guide Project of Liaoning Province(Grant No.2021-Ms-298)Scientific Research Project Department of Education in Liaoning Pr ovince(Grant No.JDL2020006)+1 种基金Liaoning Provincial Department of Education Higher Education Innovative Talent Support Program in 2020,National Natural Science Foundation of China(Grants No.U1934219,52202392 and 52022010)Talent Fund of Beijing Jiaotong University(Grant No.2021RC276).
文摘A new fault diagnosis method is proposed to effectively extract the fault features of the sound signal of typical faults of ZDJ9 railway point machines.A multi-entropy feature extraction method is proposed by combing multi-scale permutation entropy and wavelet packet entropy.Firstly,empirical mode decomposition is performed on sound signals to obtain modal components with different time scales.Then,multi-scale permutation entropy is extracted from these components.Meanwhile,the wavelet packet entropy of the sound signals of these sensitive nodes is obtained by analysing the reconstructed signals of the last layer nodes.Since the multi-scale permutation entropy and the wavelet packet entropy can distinguish the subtle features of the signal,the subtle features of the information among the high-dimensional features,ReliefF is utilized.Finally,a support vector machine(SVM)is used to judge the original sismal can be obtained as the feature vector of the 2DJ9 iway point mnchine in ditterent states,To reduce the redundant fault type of a ZDJ9 rilway point machine.