检索结果-南通市图书馆

High Voltage 2024年第1期9卷 81-93页

作者： Jun Xie Zhe Zhou Ziqian Liu Haonan Tian Sigang Zhang Qing Xie Hebei Provincial key laboratory of power Transmission Equipment Security Defense North China Electric Power UniversityBaodingChina state Grid Gansu Electric power Company LanzhouChina

Fibre-reinforced polymer(FRP)/rigid polyurethane foam(RPUF)interface is susceptible to moisture intrusion in addition to natural ageing during *** study investigated the influence of moisture intrusion on the FRP/RPUF interface under natural ageing using experiments and molecular dynamics(MD)*** absorption,shear strength,and leakage current tests were used to clarify the changes in the interface *** degradation mechanism of moisture intrusion at the interface under natural ageing was revealed by MD simulation and *** results show that the natural ageing of interfacial materials will slightly reduce the quality of the interface but will reduce the water resistance of the material and promote the process of water intrusion into the *** addition,water mainly invades the interface through *** water penetration,the interfacial bonding strength and insulation performance significantly *** and hydrolysis of interfacial materials are the main reasons for decreased interfacial *** can cause irreversible damage to the interface,increasing interface defects and water *** vicious cycle of material hydrolysis is the ultimate cause of interfacial *** polar molecules produced by this process and the water absorbed by the interface caused the degradation of the interface insulation performance.

关键词： interface polyurethane interfacial

Characteristics of Controlled Bridge Circuit and Its Application in Magnetic Field Induction Measurement

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Tsinghua Science and Technology 2024年第4期29卷 1105-1117页

作者： Yanchu Li Qingqing Ding Mingchen Yan Jiyao Wang Jun Xu Xinzhou Dong Department of Electrical Engineering Tsinghua UniversityBeijing 100084China state key laboratory of Control and Simulation of power system and Generation Equipments Tsinghua UniversityBeijing 100084China School of Electrical and Electronic Engineering North China Electric Power UniversityBeijing 100096China

The article designs a new type of bridge circuit with a controlled source—when the resistance on the bridge arm of the controlled source bridge circuit meets the bridge balance condition, and the bridge branch contains only one Current-Controlled Current Source (CCCS), a Voltage-Controlled Current Source (VCCS), a Current-Controlled Voltage Source (CCVS), or a Voltage-Controlled Voltage Source (VCVS), the circuit is called a controlled bridge circuit, which has the characteristics of bridge balance. Due to the relationship between the controlled source and the bridge arm, the sensitivity of the components on the bridge is higher mathematically and logically. When applied to measurement, engineering, automatic control, and other fields, the controlled bridge circuit has higher control ac-curacy. Mathematical derivation and simulation results prove the correctness of the bridge balance conclusion and the special properties of this bridge when applied to the measurement field.

关键词： bridge bircuit bridge circuit applications bridge balanced condition controlled bridge circuit magnetic field induction measurement

Research on vibration energy harvesting technology of power equipment based on alternating magnet array

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

High Voltage 2024年第2期9卷 336-345页

作者： Pinlei Lv Chengyu Fan Aijun Yang Huan Yuan Jifeng Chu Mingzhe Rong Xiaohua Wang state key laboratory of Electrical Insulation and power Equipment Xi'an Jiaotong UniversityXi'anChina state Grid Sichuan Electric power Research Institute ChengduChina

Vibration with a frequency of 100 Hz is widely distributed in the power equipment,and it can provide a new way to supply energy for sensors by vibration energy *** vibration energy harvesting method based on electromagnetic induction principle was studied through the arrayed structure of magnets and *** magnetic field models were established for four magnet array structures and it was found that the alternating magnet array has the largest magnetic flux and magnetic flux *** on the alternating magnet array,prototypes of energy harvester with vertical and parallel movement mode were *** structural parameter optimisation analysis,two different energy harvesters were fabricated and it was found that the energy harvester with a parallel movement mode has better output *** energy harvester could provide output voltage/current and power of 8.35 V/17.39 mA and 15.13 mW(matched resistance is 200Ω)at an acceleration of 5 m⋅s^(-2).The 100 mF capacitor could be charged to 2.72 V within 300 s,and the final voltage of the capacitor is greater than 3 V,which could sustainably drive commercial wireless temperature/humidity sensors.

关键词： power energy alternating

Fast measurement and prediction method for electromagnetic susceptibility of receiver

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of systems Engineering and Electronics 2024年第2期35卷 275-285页

作者： CHEN Yan LU Zhonghao LIU Yunxia state key laboratory of Complex Electromagnetic Environment Effects on Electronics and Information system College of Electronic Science and TechnologyNational University of Defense TechnologyChangsha 410073China state key laboratory of Astronautic Dynamics Xi’an 710043China

Aiming at evaluating and predicting rapidly and accurately a high sensitivity receiver’s adaptability in complex electromagnetic environments,a novel testing and prediction method based on dual-channel multi-frequency is proposed to improve the traditional two-tone ***,two signal generators are used to generate signals at the radio frequency(RF)by frequency scanning,and then a rapid measurement at the intermediate frequency(IF)output port is carried out to obtain a huge amount of sample data for the subsequent ***,the IF output response data are modeled and analyzed to construct the linear and nonlinear response constraint equations in the frequency domain and prediction models in the power domain,which provide the theoretical criteria for interpreting and predicting electromagnetic susceptibility(EMS)of the *** experiment performed on a radar receiver confirms the reliability of the method proposed in this *** shows that the interference of each harmonic frequency and each order to the receiver can be identified and predicted with the sensitivity *** on this,fast and comprehensive evaluation and prediction of the receiver’s EMS in complex environment can be efficiently realized.

关键词： electromagnetic susceptibility(EMS) receiver dualchannel multi-frequency nonlinear response frequency domain power domain

Optimal Configuration of Fault Location Measurement Points in DC Distribution Networks Based on Improved Particle Swarm Optimization Algorithm

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Energy Engineering 2024年第6期121卷 1535-1555页

作者： Huanan Yu Hangyu Li He Wang Shiqiang Li key laboratory of Modern power system Simulation and Control&Renewable Energy Technology Ministry of EducationNortheast Electric Power UniversityJilin132012China

The escalating deployment of distributed power sources and random loads in DC distribution networks hasamplified the potential consequences of faults if left uncontrolled. To expedite the process of achieving an optimalconfiguration of measurement points, this paper presents an optimal configuration scheme for fault locationmeasurement points in DC distribution networks based on an improved particle swarm optimization ***, a measurement point distribution optimization model is formulated, leveraging compressive *** model aims to achieve the minimum number of measurement points while attaining the best compressivesensing reconstruction effect. It incorporates constraints from the compressive sensing algorithm and networkwide viewability. Subsequently, the traditional particle swarm algorithm is enhanced by utilizing the Haltonsequence for population initialization, generating uniformly distributed individuals. This enhancement reducesindividual search blindness and overlap probability, thereby promoting population diversity. Furthermore, anadaptive t-distribution perturbation strategy is introduced during the particle update process to enhance the globalsearch capability and search speed. The established model for the optimal configuration of measurement points issolved, and the results demonstrate the efficacy and practicality of the proposed method. The optimal configurationreduces the number of measurement points, enhances localization accuracy, and improves the convergence speedof the algorithm. These findings validate the effectiveness and utility of the proposed approach.

关键词： Optimal allocation improved particle swarm algorithm fault location compressed sensing DC distribution network

Lead-free(Ba,Sr)TiO_(3)-based ceramics with superior tunable properties by the semi-solution method

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2024年第6期13卷 746-756页

作者： Yi Zhao Wenfeng Liu Dongsheng Ran Yihang Jin Zhiyuan Li Chengzhi Zhong Fanyi Kong Shengtao Li state key laboratory of Electrical Insulation and power Equipment Xi’an Jiaotong UniversityXi’an 710049China Jiaxing Electric power Company state Grid Zhejiang Electric power Co. Ltd.Jiaxing 314000China

High-performance dielectric tunable materials with both high dielectric tunability and low dielectric loss are urgently needed for new-generation electronic tunable *** the present study,a new system,(Ba_(0.675)Sr_(0.325))_(1−x)La_(x)Ti_(1−x)MnxO_(3)(x=0.25%,0.5%,0.75%,and 1.0%),was *** acceptor dopant Mn was added to lower dielectric loss,while the donor dopant La was introduced to enhance dielectric *** samples were prepared using the conventional solid-state(CS)reaction method and the semi-solution(SS)*** experimental results showed that the morphology of the ceramics was optimized by further improving the processing *** microstructures,homogeneous grains,and uniform dopant distributions could be achieved successfully by the semi-solution ***,a significant enhancement in the tunable properties was realized owing to the improved microstructure mentioned *** optimum tunable properties occurred in the samples prepared by the semi-solution method at x=0.75%,with a high dielectric tunability of 85.0%,a low dielectric loss of 0.0011,and an excellent figure of merit(FOM)of *** tunable properties of(Ba,Sr)TiO_(3)(BST)ceramics were even superior to those of lead-based materials,with an FOM of approximately *** the results suggested that the semi-solution method rendered BST ceramics more promising for applications in tunable devices.

关键词： microstructure tunable properties (Ba,Sr)TiO_(3)(BST)ceramics semi-solution(SS)method

Increasing operational stability of journal bearing in hydraulic suspension micro-pump by herringbone grooved structure

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2024年第3期67卷 853-862页

作者： HONG Tao XING GuanYing ZUO HuaiYu XUE Song LUO XiaoBing state key laboratory of Coal Combustion School of Energy and Power EngineeringHuazhong University of Science and TechnologyWuhan 430074China

The operational stability of radial journal bearings is the bottleneck that limits the reliability of hydraulic suspension micropump. Due to self-excited vibrations, the whirl amplitude of the plain journal bearing(PJB) is large at high rotational speeds,which will accelerate wear failure. It has been proven that employing herringbone grooved journal bearing(HGJB) is an effective method to reduce the whirl amplitude and improve operational stability. However, enhancing the stability of journal bearings in micro-pumps by herringbone grooved structures has rarely been studied, and its effect needs to be verified. We validated the mechanism of the stability improvement with the CFD method and compared the dynamic characteristics of HGJB and PJB by rotor dynamics evaluation and experiment. The experimental results show that under the same conditions the whirl amplitude of the HGJB decreases by 29.61% in the x direction and by 24.09% in the y direction compared with that of the PJB. This study reveals the effect of the herringbone grooved structure on the operational stability of bearings and may provide guidance for the reliability improvement of hydraulic suspension micro-pump.

关键词： journal bearing herringbone groove hydrodynamic effect micro-pump

An angular blinking jamming method based on electronically controlled corner reflectors

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of systems Engineering and Electronics 2024年第2期35卷 330-338页

作者： GAN Lin WU Zehao WANG Xuesong LI Jianbing state key laboratory of Complex Electromagnetic Environmental Effects on Electronics and Information system National University of Defense TechnologyChangsha 410073China

Passive jamming is believed to have very good potential in countermeasure *** this paper,a passive angular blinking jamming method based on electronically controlled corner reflectors is *** amplitude of the incident wave can be modulated by switching the corner reflector between the penetration state and the reflection state,and the ensemble of multiple corner reflectors with towing rope can result in complex angle decoying *** of the decoying effect on corner reflectors’radar cross section and positions are analyzed and *** show that the angle measured by a monopulse radar can be significantly interfered by this method while the automatic tracking is employed.

关键词： monopulse radar angular blinking jamming corner reflector amplitude-comparison angle measurement metasurface

Closed-form solution to the dynamic programming for a heavy-duty parallel hybrid vehicle energy management

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Control and Decision 2024年第1期11卷 107-116页

作者： Tao Zhang Zhongjun Yu Huangda Lin National key laboratory for Vessel Integrated power system Technology Naval University of EngineeringWuhanPeople’s Republic of China

Dynamic programming(DP)is frequently used to obtain the optimal solution to the hybrid electric vehicle(HEV)energy *** trade-off between the accuracy and the computational effort is the biggest problem for the DP *** closed-form solution to the DP is proposed to solve this ***,the affine linear model of the engine fuel rate is obtained based on engine test *** piecewise linear approximation of the motor power demand is obtained considering the different energy flows in the charging and discharging stages of the ***,the second-order Taylor expansion for the cost matrix at each time and state grid point is introduced to get the closed-form solution of the optimal torque *** results show that this method can greatly reduce the computing burden by 93%while ensuring near-optimal fuel economy compared with the conventional DP method.

关键词： Dynamic programming energy management closed-form solutions fuel economy hybrid electric vehicles

Analysis of SF6 decomposed products by fibre-enhanced Raman spectroscopy for gas-insulated switchgear diagnosis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

High Voltage 2024年第1期9卷 206-216页

作者： Jianxin Wang Weigen Chen Pinyi Wang Fu Wan Zhixian Zhang Shoufei Gao Yingying Wang School of Electrical Engineering Chongqing UniversityChongqingChina state key laboratory of power Transmission Equipment&system Security and New Technology Chongqing UniversityChongqingChina Institute of Photonics Technology Jinan UniversityGuangzhouChina

Sulphur hexafluoride(SF6)decomposed products analysis is highly critical in the earlystage fault diagnosis of gas-insulated switchgear(GIS).Spectrum technology outperforms traditional methods on non-invasiveness,no sample preparation,and no ***,the authors present an improved fibre-enhanced Raman spectroscopy(FERS)as a comprehensive analytical tool to detect a suite of SF_(6)decomposed products(SO_(2)F_(2),SOF_(2),SO_(2),H_(2)S,CF_(4),OCS,CO_(2),and CO).The FERS approach is combined with two iris diaphragms for spatial filtering and a rear-end reflector for additional Raman signal *** of detection down to 1×10^(−6)–8×10^(−6)are achieved for different SF6 decompositions,and quantification of an undefined multigas,sampled from an 800 kV GIS in service,is realised utilising SF6 as the internal standard gas and with a maximum error of 5.5%.The GIS is diagnosed according to the results and confirmed by an on-site *** authors foresee that this technique will provide a route for trace gas analysis in the power industry.

关键词： SF6 diagnosis fibre