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High Voltage 2024年第5期9卷 1011-1020页

作者： Yingfan Zhang Haohuan Wang Zhengyong Huang Jian Li State key laboratory of power transmission equipment technology Chongqing UniversityChongqingChina

Surface flashover is a crucial issue for the miniaturisation of electronic facilities in military,industrial,and aerospace *** oriented hexagonal boron nitride(hBN)composites,due to excellent thermal and electrical insulating properties,show a potential application in high-voltage power equipment,while the surface flashover performance of hBN composites dependent on oriented hBN texture is rarely *** effects of hBN orientation and contents on the surface flashover performances of oriented hBN composites are *** isothermal surface potential decay of the oriented hBN composites was also *** is found that the charge transportation could be adjusted by the hBN orientation,thus regulating surface flashover *** DC flashover voltage of the in-plane oriented hBN composites with a thickness of 15μm reached the maximum of 27.6 kV at the hBN loading of 20 wt%,14.5%higher than that of the pure *** carrier mobility of out-of-plane oriented hBN composites is about three times greater than that of the in-plane oriented composites,indicating that the charges are easily transported along the hBN basal *** larger carrier mobility causes charge dissipation in composites near the electrode at the hBN basal plane parallel to the axis of electrodes and inhibits the distortion of the surface electric field on the composites,thus enhancing the surface ***,developing oriented insulators for highvoltage applications and enabling an optimum insulation design would be beneficial because of the compactness and high reliability of power apparatus for use in power grids.

关键词： composites surface boron

Maximum power Point Tracking Based on Improved Kepler Optimization Algorithm and Optimized Perturb&Observe under Partial Shading Conditions

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Energy Engineering 2024年第12期121卷 3779-3799页

作者： Zhaoqiang Wang Fuyin Ni School of Electrical and Information Engineering Jiangsu University of TechnologyChangzhou213001China jiangsu key laboratory of power transmission&distribution equipment technology JiangsuUniversity of TechnologyChangzhou213001China

Under the partial shading conditions(PSC)of Photovoltaic(PV)modules in a PV hybrid system,the power output curve exhibits multiple *** often causes traditional maximum power point tracking(MPPT)methods to fall into local optima and fail to find the global *** address this issue,a composite MPPT algorithm is *** combines the improved kepler optimization algorithm(IKOA)with the optimized variable-step perturb and observe(OIP&O).The update probabilities,planetary velocity and position step coefficients of IKOA are nonlinearly and adaptively *** adaptation meets the varying needs of the initial and later stages of the iterative process and accelerates *** stochastic exploration,the refined position update formulas enhance diversity and global search *** improvements in the algorithmreduces the likelihood of falling into local *** the later stages,the OIP&O algorithm decreases oscillation and increases *** with cuckoo search(CS)and gray wolf optimization(GWO),simulation tests of the PV hybrid inverter demonstrate that the proposed IKOA-OIP&O algorithm achieves faster convergence and greater stability under static,local and dynamic shading *** results can confirm the feasibility and effectiveness of the proposed PV MPPT algorithm for PV hybrid systems.

关键词： PV hybrid inverter kepler optimization algorithm maximum power point tracking perturb and observe

The Full Load Voltage Compensation Strategy in Capacity Configuration of UPQC Integrated PV-BESS

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Energy Engineering 2023年第5期120卷 1203-1221页

作者： Fuyin Ni Kai Li jiangsu key laboratory of power transmission&distribution equipment technology JiangsuUniversity of TechnologyChangzhou213001China School of Electrical and Information Engineering Jiangsu University of TechnologyChangzhou213001China

Unified power quality conditioner(UPQC)with energy storage is commonly based on conventional capacity configuration strategy with power angle *** has problems such as phase jumping before and after ***-link cannot continuously emit active power ***,this paper presents the compensation strategy of full load voltage magnitude and phase in capacity configuration of *** topology of UPQC is integrated a series active power filter(SAPF),a shunt active power filter(PAPF)and a photovoltaic-battery energy storage system(PV-BESS).The principle of full load voltage compensation is analyzed based on the PV-BESS-UPQC *** constant of load voltage ismaintained by controlling the appropriate shunt compensation *** the UPQC capacity configuration is carried out using the full load voltage compensation *** compensation capacity of UPQC series and shunt units are ***,the simulation results show that the proposed compensation strategy reduces the capacity configuration by 5.11 kVA(36.4%)compared to the conventional compensation *** proposed strategy can achieve full compensation of the load voltage,which can effectively reduce the capacity allocation and improve the economy of *** also has the PV-BESS units’ability of providing active power and can stabilize the DC-link voltage.

关键词： Unified power quality conditioner solar photovoltaic battery energy storage system full compensation capacity configuration strategy

Local electron mean energy profile of positive primary streamer discharge with pin-plate electrodes in oxygen nitrogen mixtures

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Chinese Physics B 2013年第1期22卷 394-402页

作者：司马文霞彭庆军杨庆袁涛施健 State key laboratory of power transmission equipment & System Security and New technology Chongqing University

Local electron mean energy （LEME） has a direct effect on the rates of collisional ionization of molecules and atoms by electrons. Electron-impact ionization plays an important role and is the main process for the production of charged particles in a primary streamer discharge. Detailed research on the LEME profile in a primary streamer discharge is extremely important for a comprehensive understanding of the local physical mechanism of a streamer. In this study, the LEME profile of the primary streamer discharge in oxygen-nitrogen mixtures with a pin-plate gap of 0.5 cm under an impulse voltage is investigated using a fluid model. The fluid model includes the electron mean energy density equation, as well as continuity equations for electrons and ions and Poisson＇s electric field equation. The study finds that, except in the initial stage of the primary streamer, the LEME in the primary streamer tip tends to increase as the oxygen-nitrogen mole ratio increases and the pressure decreases. When the primary streamer bridges the gap, the LEME in the primary streamer channel is smaller than the first ionization energies of oxygen and nitrogen. The LEME in the primary streamer channel then decreases as the oxygen-nitrogen mole ratio increases and the pressure increases. The LEME in the primary streamer tip is primarily dependent on the reduced electric field with mole ratios of oxygen-nitrogen given in the oxygen-nitrogen mixtures.

关键词： local electron mean energy profile primary streamer discharge electric field distribution gas discharge

Semiglobal Saturated Practical Stabilization for Nonholonomic Mobile Robots With Uncertain Parameters and Angle Measurement Disturbance

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Semiglobal Saturated Practical Stabilization for Nonholonomi...

Morphological analysis for thermodynamics of cavitation collapse near fractal solid wall

第25届中国控制与决策会议

作者： Hua Chen Jinbo Zhang Mathematics and Physics Department Hohai University jiangsu key laboratory of power transmission and distribution equipment technology Hohai University

ISBN: (纸本)9781467355339

In this paper, the semiglobal stabilization problem is addressed for a class of uncertain nonholonomic mobile robots with input saturation. By solving the linear inequalities, a new switching controller is presented in the presence of parametric uncertainties and angle measurement disturbance. Under the proposed controller, it is rigorously proved that all the states of the closed loop system can be stabilized to the any prescribed small interval around zero. Finally, a numerical example illustrate the effectiveness of the control design method.

关键词： Nonholonomic mobile robots input saturation uncertain parameters angle measurement disturbance.

来源： cnki会议评论

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Chinese Physics B 2024年第6期33卷 422-432页

作者：单鸣雷杨雨阚雪芬殷澄韩庆邦 jiangsu key laboratory of power transmission and distribution equipment technology Hohai UniversityChangzhou 213022China College of Information Science and technology Nanjing Forestry UniversityNanjing 210000China Department of Transportation Engineering Jiangsu Shipping CollegeNantong 226000China

A fractal geometric boundary with natural wall features is introduced into a hybrid lattice-Boltzmann-method(LBM)multiphase model. The physical model of cavitation bubble collapse near the irregular geometric wall is established to study the thermodynamic characteristics of the bubble collapse. Due to the lack of periodicity, symmetry, spatial uniformity and obvious correlation in the LBM simulation of the bubble collapse near the fractal wall, the morphological analysis based on Minkowski functional is introduced into the thermodynamic investigation of cavitation bubble so as to analyze and obtain the effective information. The results show that the Minkowski functional method can employed to study the temperature information in complex physical fields hierarchically and quantitatively. The high/low temperature region of the cavitation flow is explored, and thermal effect between irregular and fractal geometric wall and cavitation bubble can be revealed. It illustrates that LBM and morphological analysis complement each other, and morphological analysis can also be used as an optional and potential tool in research field of complex multiphase flows.

关键词： lattice Boltzmann method cavitation bubble morphological analysis

Loss induced negative refraction and super-prism effect at highly absorptive interface

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Chinese Physics B 2019年第5期28卷 101-105页

作者： Jian Wu Tao Wang Tianyue Hou Xuefen Kan Cheng Yin Pu Zhou Zhuangqi Cao College of Advanced Interdisciplinary Studies National University of Defense Technology Hunan Provincial key laboratory of High Energy Laser technology jiangsu key laboratory of power transmission and distribution equipment technology Hohai University College of Physics and Astronomy Shanghai Jiao Tong University

It is well-established that waves are inhomogeneous in a lossy isotropic medium, and the validation of the classical Snell's law is still questionable for light refraction at the dissipative and dispersive interface. With high absorption, direct experimental investigation is rather difficult due to the extremely short penetration depth; i.e., the skin depth. In this paper, a simple and unified description of this issue is proposed, which can be applied to both materials with anomalous dispersion and in the Drude region. The gradient ▽_k~ω is found to be incident angle θ_i-dependent, and the direction of the group velocity may deviate significantly from the phase velocity due to the loss induced permittivity structure. The physics behind the negative refraction effect is explained, and a novel loss induced super-prism effect is also predicted.

关键词： Snell’s Law Drude model anomalous dispersion lossy isotropic media

Propagation dynamics of off-axis noncanonical vortices in a collimated Gaussian beam

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Chinese Physics B 2019年第3期28卷 192-196页

作者： Cheng Yin Xuefen Kan Hailang Dai Minglei Shan Qingbang Han Zhuangqi Cao jiangsu key laboratory of power transmission and distribution equipment technology Hohai UniversityChangzhou 213022China The State key laboratory on Fiber Optic Local Area Communication Networks and Advanced Optical Communication Systems Shanghai JiaoTong UniversityShanghai 200240China

It is widely accepted that an off-axis noncanonical vortex moves across the free-space diffracting Gaussian beam without rotation. But our analysis shows that the vortex swirls a while before it approaches infinite. By neglecting the divergence of the host beam, we focus on this rotation characteristics of the vortices in linear homogeneous media. For the symmetrical host beam, it is found that the vortex moves along an elliptical trajectory, while the topological charge and the angular momentum of the vortex core relative to the beam axis are conserved. For the asymmetrical host beam, the vortex trajectory is rather complicated, since the noncanonical parameter varies as the light propagates, resulting in topological charge inversion. But we find that the vortices are always confined in a rectangular area, and the rotation direction is determined by the topological charge.

关键词： noncanonical optical vortex topological charge inversion

Fast electrothermal coupling calculation method for supporting digital twin construction of electrical equipment

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High Voltage 2023年第2期8卷 390-400页

作者： Xiaosong Zhu Youyuan Wang Ruixiao Meng Shi Long Shaowen Wu State key laboratory of power transmission equipment and System Security and New technology(Chongqing University) ChongqingChina

The failure of electrical equipment directly or indirectly caused by overheating has become one of the main reasons for equipment *** real-time condition monitoring method of electrical equipment based on digital twin(DT)has received extensive attention and is considered as a technology with great engineering values and excellent application ***,the current calculation of DT mostly relies on the traditional finite element method(CFEM).This method becomes less computationally efficient as the size of the DT increases,especially for electrical equipment with high *** is difficult to meet the requirements real-time calculation in ***,starting from the algorithm optimization and parallel architecture,based on the weighted residual method and stabilised conforming nodal integration,a novel discrete method of electrothermal coupling equation is proposed and the data storage structure of the algorithm from the bottom layer is redesigned,and the corresponding GPU and multi-core CPU parallel framework are ***,taking the high voltage bushing as an example,the correctness of the method in this paper is verified by the CFEM code and commercial software *** the same grid and accuracy requirement,the calculation time is shortened by at least five times than *** the method is easy to extend to other types of multi-physics calculations.

关键词： electrical coupling method

Microstructure-ionisation potential relationship analysis for understanding the molecular ionisation difference of natural esters during the impulse discharge via DFT calculation

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High Voltage 2024年第4期9卷 920-929页

作者： Jingwen Zhang Jian Hao Wenyu Ye Junyi Zhang Ruijin Liao State key laboratory of power transmission equipment technology School of Electrical/EngineeringChongqing UniversityChongqingChina

Understanding the impulse discharge behaviour of natural ester(NE)is crucial for its safe application in high-voltage *** ionisation potential(IP)of triglycerides plays a significant role in the process of molecular ionisation during impulse discharge for *** correlation coefficients between molecular size,frontier orbital,electrostatic potential,polarity,and IP were *** the quantitative microstructure-IP model for triglycerides were built,which revealed that IP is strongly related to the highest occupied molecular orbital(HOMO)energy EHM,as well as the average value of positive electrostatic potential V_(p)(t),the average value of negative electrostatic potential V_(p)(-),and the surface area of negative electrostatic potential S(-).The HOMO and negative electrostatic potentials of saturated triglycerides are predominantly linked to the carbonyl O ***,in unsaturated triglycerides,the influence of C=C double bonds on HOMO and negative electrostatic potentials is more ***,the IP of unsaturated NE with C=C bonds is lower than that of saturated NE,rendering it more susceptible to ionisation under a strong electric field which is unfavourable for impulse breakdown *** structure-property correlation analysis is valuable for understanding ionisation mechanism during the impulse discharge breakdown of NE at the microscopic level.

关键词： electrostatic potential bonds