检索结果-内蒙古大学图书馆

Delamination failure analysis of G10 insulator in electromagnetic rail launcher

High Voltage 2023年第5期8卷 889-897页

作者： Xinkai Hu Junyong Lu Sai Tan Bai Li Jiawei Zhang National Key Laboratory of Science and Technology on Vessel Integrated Power System Naval University of EngineeringWuhanHubeiChina

The electromagnetic(EM)rail launcher G10 insulator is prone to delamination damage during launch,which affects the service life of the *** the secondary development of ABAQUS®commercial finite‐element software,an EM‐structure coupling launch dynamics model considering projectile‐barrel coupling is *** simulation indicates that the transverse swing of the projectile changes in a sine‐like law,and the time of the upper half wave corresponds to the pulse width of the impact force pulse *** stress concentration occurs on the inner surface of the insulator where the contact‐impact occurs,resulting in impact *** midline of the insulator inner surface bears a large compressive strain under the action of pre‐tightening force,and the insulator is compressed oscillatingly under the influence of the timevarying load of the rail during *** the condition of repeated launch,the launch package repeatedly impacts the insulator,and the alternating load of the rail is cyclically loaded on the insulator with impact damage,which will cause the compression fatigue of the insulator and the expansion of impact damage *** are the main reasons for the delamination failure of insulator,and the experimental analysis is carried *** study provides a method to study the delamination failure mechanism of the insulator,and provides guidance for improving the life of the insulator.

关键词： insulator damage analysis

来源：评论

学校读者我要写书评

暂无评论

A Fast Positioning Method of Navigation Receiver Assisted by Doppler Information 14th

A Fast Positioning Method of Navigation Receiver Assisted by...

引用

14th China Satellite Navigation Conference, CSNC 2024

作者： Tang, Yinyin Lu, Junyong Feng, Junhong Li, Kai National Key Laboratory of Science and Technology on Vessel Integrated Power System Naval University of Engineering Wuhan430033 China

ISBN: (纸本)9789819969319

In order to shorten the time to first fix (TTFF) of the satellite receiver, a fast positioning method using both carrier and pseudo code observation is proposed. First, use the Doppler information acquired by the carrier tracking loop to reduce the a priori time accuracy to 100 s. Then, use the code phase acquired by pseudo-code tracking loop, and use the five-state equation to solve the receiver position. In this way, positioning can be achieved before frame synchronization and bit synchronization. Numerical simulation and test results show that positioning can be achieved within 1s through Beidou/GPS dual system in the global or BeiDou alone in the Asia-Pacific region, when the a priori position accuracy is less than 10 km and the a priori time accuracy is less than 2 h. © Aerospace Information Research Institute 2024.

关键词： Equations of state

来源：评论

学校读者我要写书评

暂无评论

Investigation on influence of gamma irradiation on piezoelectric and resonance characteristics of surface acoustic wave resonators 5

Investigation on influence of gamma irradiation on piezoelec...

引用

5th International Conference on Mechanical Engineering and Materials, ICMEM 2024

作者： Sun, Lei Peng, Bin Yang, Yuntao Sun, Zhaofeng Zhu, Jialiang Zhang, Wanli State Key Laboratory of Electronic Thin Films and Integrated Devices University of Electronic Science and Technology of China Chengdu China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu China

ISBN: (数字)9781510688971

ISBN: (纸本)9781510688964

In this work, an evaluation towards influence of high-dose gamma irradiation on surface acoustic wave (SAW) resonators, is reported. The single-port SAW resonators are fabricated using Lithium niobate (LiNbO3) and Catangasite (CTGS, Ca3TaGa3Si2O14) substrates, along respective cut directions of (0º, 38º, 0º) and (0º, 90º, 0º). Piezoelectric coefficient of substrates, and several main resonance parameters covering resonance frequency, amplitude of resonance peak in reflection coefficient, quality factor together with electromechanical coupling factor of manufactured SAW resonators are investigated, as suitable representatives of piezoelectric and resonance characteristics of SAW resonators. After exposure to gamma ray with a maximum dose of 250 kGy, substrates show insignificant variation not exceeding 6% in their piezoelectric coefficient. Meanwhile, resonance parameters of SAW resonators also alter slightly. Such excellent stability of these characteristics demonstrates credible irradiation hardness owned by both SAW resonators. Results in this study can provide supportive references for usage of LiNbO3 and CTGS-based SAW devices in harsh environments. © 2025 SPIE.

关键词： Gamma rays

来源：评论

学校读者我要写书评

暂无评论

On the improvement of power conversion efficiency of parametric arrays

引用

Chinese Journal of Acoustics 2023年第4期42卷 450-463页

作者： LU Zhimiao MENG Jin WANG Bo ZHAO Zhihua HU Anqi National Key Laboratory of Science and Technology on Vessel Integrated Power System Technology Naval University of EngineeringWuhan 430000

Due to the low power conversion efficiency of parametric array, the proposed method can be used to improve the power conversion efficiencies of parametric arrays by adjusting the specific acoustic impedance. The Kuznetsov equation that describes parametric arrays is first studied, the inffuence of Lagrangian densities on difference frequency wave is analyzed,and the relationship between the Lagrangian density and the acoustic impedance is ***, the method of arranging perforated plates around the parametric array to adjust the acoustic impedance is proposed. The proposed method is validated through numerical simulations. The results show that this method can improve the power conversion efficiency of the parametric array by using perforated plates to change the acoustic impedance.

关键词： parametric impedance method

来源：评论

学校读者我要写书评

暂无评论

A Data-Driven Open-Circuit Fault Diagnosis Method for Three-Phase T-type Three-level Inverters 3

A Data-Driven Open-Circuit Fault Diagnosis Method for Three-...

引用

3rd IEEE International power Electronics and Application Conference and Exposition, PEAC 2022

作者： Wang, Yifan Xu, Xiaohui Qiu, Changqing Zheng, Zedong Wang, Kui Li, Yongdong Tsinghua University Department of Electrical Engineering Beijing China Science and Technology on Ship Integrated Power System Technology Laboratory Wuhan China

ISBN: (数字)9781665491419

ISBN: (纸本)9781665491419

This paper presents a data-driven diagnosis method for single-switch open-circuit faults in T-type three-level inverters based on current vector trajectory and convolutional neural network (CNN). First, a simulation model based on T-type topology is built and the three-phase current waveforms under different model parameters are recorded as the dataset. The current vector trajectories are extracted through Clarke transform as the feature (60 × 60). The trajectories are then classified using a convolutional neural network to identify the fault. The method achieved an average validation accuracy rate higher than 99% and is validated through simulation and experiment. It is robust to white noise and changes in model parameters, dc-link voltage, modulation rate, and frequency. © 2022 IEEE.

关键词： Trajectories

来源：评论

学校读者我要写书评

暂无评论

Analysis of the impact of long-term service of inverter devices on electromagnetic compatibility 2

Analysis of the impact of long-term service of inverter devi...

引用

2nd China power Supply Society Electromagnetic Compatibility Conference, CPEMC 2024

作者： Zhang, Ruiheng Pei, Xuejun Meng, Jin Fan, Hongming Zhou, Peng Yuan, Yuzhang Power Electronics and Energy Management Key Laboratory Ministry of Education of China Huazhong University of Science and Technology Wuhan China National Key Laboratory of Science and Technology on Vessel Integrated Power System Naval University of Engineering Wuhan China

ISBN: (纸本)9798331509552

Taking the IGBT power module of the inverter device as the research object, finite element analysis technology was used to explore the influence of long-term service on the thermal characteristics and stress-strain of the IGBT module. At the same time, the influence of service aging on the electromagnetic compatibility performance of the device was studied, and the finite element simulation results were verified through accelerated aging experiments. The results showed that during the long-term operation of the IGBT module, due to the different thermal expansion coefficients of its materials, strain differences were found, ultimately leading to an increase in its ground capacitance, resulting in an increase in the amplitude of the common mode conducted noise of the device by 3dBμA in the frequency band after 20MHz. This study will provide theoretical guidance for the electromagnetic compatibility design of inverter devices for long-term service. ©2024 IEEE.

关键词： Insulated gate bipolar transistors (IGBT)

来源：评论

学校读者我要写书评

暂无评论

Analysis and Design of Wireless power and Information Synchronous Transmission system with Shared Coupling Channel 5

Analysis and Design of Wireless Power and Information Synchr...

引用

5th IEEE International Electrical and Energy Conference, CIEEC 2022

作者： Yali, Yang Kai, Ji Bangyin, Liu Yadong, Wang Aoni, Sun Huazhong University of Science and Technology Wuhan China Wuhan Institute of Marine Electric Propulsion Science and Technology on Ship Integrated Power System Technology Laboratory Wuhan China

ISBN: (数字)9781665411042

ISBN: (纸本)9781665411042

The technology of wireless power and information synchronous transmission (WPIT) broadens the application scenario of the system. In this paper, the power transmission channel and information transmission channel of WPIT system are modeled and analyzed in detail. Frequency division multiplexing technology is adopted, and different frequency carriers are used for power and information transmission. The composite circuit of power and information transmission is introduced, and the function of each element of the circuit is explained in detail. Furthermore, the methods of signal modulation and demodulation are given. In order to realize the decoupling design of power and information transmission circuit, the crosstalk between power and information carrier is discussed. Then, the channel of power and information transmission are given respectively to analyze the power transmission performance and communication transmission gain. It provides guidance for the parameter design of information transmission circuit. Finally, an experimental prototype is built, with an output power of 200W and a data transmission rate of 200kbps. © 2022 IEEE.

关键词： Inductive power transmission

来源：评论

学校读者我要写书评

暂无评论

Modulation and Voltage Balancing Control of Dual Five-level ANPC Inverter for ship Electric Propulsion systems

引用

Chinese Journal of Electrical Engineering 2021年第4期7卷 78-92页

作者： Xiaohui Xu Xingchi Song Kui Wang Nianzhou Liu Wenfeng Long Zedong Zheng Yongdong Li Science and Technology on Ship Integrated Power System Technology Laboratory Wuhan Institute of Marine Electric PropulsionWuhan 430070China China State Key Laboratory of Power System Tsinghua UniversityBeijing 100084China

Open-end winding motors are used extensively in ship electric propulsion systems,in which medium-voltage high-power inverters are a critical *** increase the system voltage and power density,a dual five-level active neutral-point clamped(ANPC)inverter is proposed herein to drive medium-voltage open-end winding motors for ship electric *** phase of this inverter comprises two five-level ANPC bridges and all the phases are powered by a common direct-current link.A hybrid modulation method is proposed to control this *** series-connected switches in all the five-level ANPC bridges are operated at the fundamental frequency,and the other switches are controlled with a phase-shifted pulse-width modulation(PWM),which can achieve a natural balance between the neutral-point voltage and flying capacitor voltages in a carrier period.A closed-loop capacitor voltage balancing method based on adjusting the duty ratios of the PWM signals is *** neutral-point voltage and flying capacitor voltages can be controlled independently and balanced without affecting the output phase *** and experimental results are presented to demonstrate the validity of this method.

关键词： Multilevel inverter active neutral-point clamped(ANPC) capacitor voltage balance open-end winding motor drive

来源：评论

学校读者我要写书评

暂无评论

Position sensorless switching control strategy of SPMSMs based on fault tolerance of position sensor 6

Position sensorless switching control strategy of SPMSMs bas...

引用

6th IEEE International Electrical and Energy Conference, CIEEC 2023

作者： Tan, Zexin Zhu, Junjie Wu, Zhicheng Xu, Jin Naval University of Engineering National Key Laboratory of Science and Technology on Vessel Integrated Power System Wuhan China

ISBN: (纸本)9798350346671

This paper proposes a switching method based on model reference adaptive system (MRAS) from position sensor control strategy to sensorless control strategy for surface permanent magnet synchronous motor (SPMSM) drives operating in medium and high velocity regions. The proposed switching method can effectively deal with the fault of the position sensor in SPMSM system, so as to improve its safety and stability. The sensor setting of control strategy consists of an actual sensor (position sensor) and the virtual sensor (MRAS). When the system position sensor has no fault, the feedback value of the position sensor has a greater weight on the information of the rotor position and velocity of the closed-loop system, while the weight of the MRAS estimated value is lower. When the position sensor fails, the information of the rotor position and velocity of the closed-loop system is provided by MRAS algorithm. Also, a linear weighted switching method is proposed, which can effectively reduce the motor fluctuation during the switching process. The feasibility of the proposed strategy is confirmed via simulations of SPMSM drive model in MATLAB/Simulink software. © 2023 IEEE.

关键词： Fault tolerance

来源：评论

学校读者我要写书评

暂无评论

The Principle Analysis of Two-element Cross-eye Jamming Based on Phased Array

The Principle Analysis of Two-element Cross-eye Jamming Base...

引用

IET International Radar Conference 2023, IRC 2023

作者： Yang, Haonan Zhou, Liang Liu, Yongcai Su, Binbin Meng, Jin National Key Laboratory of Science and Technology on Vessel Integrated Power System Naval University of Engineering Wuhan China

ISBN: (纸本)9781839539954

The application of phased array to radar jammer is helpful to improve the effective isotropic radiated power (EIRP) and the ability to counter multiple targets. Two-element cross-eye jammer based on phased array is significantly different from traditional two-element cross-eye jammer (TTCJ) and multiple-element cross-eye jammer (MCJ) in terms of antenna elements layout, circuit architecture and signal processing. However, there are no published literatures to analyse the principle of phased array two-element cross-eye jammer (PATCJ). Therefore, a mathematical model of PATCJ against mono-pulse radar is established in this paper, and the principle and feasibility of applying phased arrays to two-element cross-eye jammer are discussed. The cross-eye gain of PATCJ is derived. Besides, it is verified that the random selection of phase-shifting reference units (PRUs) will not affect the jamming performance of PATCJ. The research results of this paper have guiding significance for the engineering realization of PATCJ. © The Institution of Engineering & technology 2023.

关键词： Antenna phased arrays

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：