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Research on Low Voltage Ride through Strategy for Power Electronic Transformer

IOP Conference Series: Materials Science and engineering 2019年第1期486卷

作者： Xiangping Kong Peng Li Jiexiang Han Zhe Zhang Xianggen Yin State Grid Jiangsu Electric Power Co. Ltd. Research Institute Nanjing Jiangsu 211103 China State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan Hubei 430074 China

In view of the operating characteristics for voltage sags of AC side of the power electronic transformer(PET), a low-voltage ride through(LVRT) strategy adapted to bidirectional power exchange of PET is proposed for the purposes of maintaining the system stability, assisting the system voltage recovery and protecting PET safety. During the asymmetric voltage sag, the negative sequence current of PET is eliminated to ensure the symmetry of the injected current. According to the degree of positive sequence voltage sag, the reactive current injection is provided to assist in voltage recovery. According to the PET active power condition before the voltage sag, the level and direction of which are maintained as far as possible without exceeding the limit, for which the disturbance to the AC and DC grids is reduced. Finally, the effectiveness of the proposed LVRT strategy is verified by simulation model.

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Meteorlogical outliers detection based on artificial intelligence

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IOP Conference Series: Earth and Environmental Science 2020年第3期474卷

作者： F Xue W Zheng M Zhang Q Wu Z Yang X Ai International Joint Research Laboratory of Magnetic Confinement Fusion and Plasma Physics State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan Hubei 430074 China China-EU Institute for Clean and Renewable Energy Huazhong University of Science and Technology Wuhan Hubei 430074 China

To precisely evaluate the effect of artificial precipitation of Project Tianshui, anomaly data within the large dataset collected is supposed to be detected and dealt with reasonably, to enhance the analysis and prediction of the data. Using the data accumulated from 2008 to 2017 from Wushaoling Meteorological Station, and the data from May 2019 to October 2019 from the dedicated supervising network built for the project, taking temperature(0.1°C) and other meteorological data as example, anomaly dectection is conducted by the arithmetics Local Outlier Factor and Isolation Forest respectively. Consistency check is also conducted via the two arithmetics. The main outliers of the accumulated data for ten years are isolated outliers. LOF works pretty well, while Isolation Forest performs unsatisfying. The main outliers of the dedicated supervising network data are of a continuous outlier sequence. LOF can hardly detect the anomaly, while Isolation Forest precisely find out the outliers. Both arithmetics perform well on consistency check in space. The differences of LOF and Isolation Forest are compared. New ideas of using artificial intelligence arithmetics to detect meteorological outliers and pre-process the data are provided.

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Distributed control system for catalysing the formation of artificial rainfall and snow using charged particles

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IOP Conference Series: Earth and Environmental Science 2020年第5期474卷

作者： Z Yang Q Wu M Zhang W Zheng Y Wang X Ai China-EU Institute for Clean and Renewable Energy Huazhong University of Science and Technology Wuhan Hubei 430074 China International Joint Research Laboratory of Magnetic Confinement Fusion and Plasma Physics State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan Hubei 430074 China

In order to solve the limitations and shortcomings of the traditional artificial rainfall technology, researchers all over the world are actively researching new artificial rainfall technologies. The charged particle catalytic artificial rainfall technology is one of the new artificial rainfall technologies. This method uses a charged particle generator set up in the wild to produce charged particles to catalyse rainfall. It is necessary to control all equipment in the experiment site remotely during the experiment. Thus, a control system needs to be implemented. There are many kinds of controlled equipment in this control system, such as high-voltage power supply, meteorological data acquisition devices, and various experimental auxiliary equipment. In this paper, we design and implement a comprehensive control system based on the characteristics of the charged particle catalysed artificial rainfall field experiment and the controlled equipment in the experiment site. The software interface connected to different types of equipment in the system is developed based on the large-scale experimental control system framework CFET, which can easily add equipment and view measurement data. The system is designed as a distributed system connected through a network, which can meet the needs of centralized control of multiple experimental sites.

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Space-charge effect of the time-varying electron injection in a diode: classical and relativistic regimes

arXiv

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arXiv 2017年

作者： Liu, Yangjié Tang, Qi Wu, Biyi Faculty of Physics and Electronic Science Hubei University Hubei Collaboration Innovation Centre for Advanced Organic Chemical Materials Hubei Key Laboratory of Ferro & Piezoelectric Materials and Devices WuhanHubei Province430062 China Antennas Group School of Electrical Engineering and Computer Science Queen Mary University of London E1 4NS Mile End East London United Kingdom Department of Mathematical Sciences Rensselaer Polytechnic Institute United States Center for Electromagnetic Simulation Beijing Institute of Technology Haidian District Beijing China

Conventionally, space-charge (SC) limited current density is defined as the maximal current density allowed to traverse a diode under a DC voltage when a time-invariant flow is injected from the cathode. In this work, we study the SC limited current density under a time-varying injection for both classical and relativistic regimes and determine the maximal amount of limited current density under certain conditions. Our simulations show that it is unlikely that a time-varying injection emitted from cathode exceeds the known SC limits, in either classical or relativistic regime. Copyright © 2017, The Authors. All rights reserved.

关键词： Current density

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An improved optimal control strategy for hybrid AC/DC power system

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IOP Conference Series: Earth and Environmental Science 2018年第1期188卷

作者： C H Gao W M Liu T T Zheng Z W Liu S H Miao Y L Kang Z H Fan Y L Liu M M Zhang State Grid East Inner Mongolia Electric Power Company Limited Electric Power Research Institute Hohhot 010020 China State Key Laboratory of Advanced Electromagnetic Engineering and Technology Hubei Electric Power Security and High Efficiency Key Laboratory School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan 430074 China

The additional modulation function of high voltage direct current (HVDC) links can improve the system stability while the unavoidable random external disturbance and sudden changes seriously affect the controller performance and the system stability. In this paper, an improved control scheme based on inverse optimal adaptive control is proposed for the hybrid AC/DC system which considers the system parameter error, external disturbance and other random perturbation. The proposed control scheme combines the inverse optimal control approach and the adaptive control method to account for the modelling errors and uncertainty, which aims at the disturbance attenuation and the optimal operating of the hybrid AC/DC power system. Besides, the improved PI (Proportional-Integral) controller based on the lead-lag link for the current control of HVDC system is proposed to further improve system dynamic performance. Simulations conducted on a typical hybrid AC/DC system show the correctness and validity of the proposed control method.

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Coordinated control strategy of doubly fed wind power generation system under unbalanced grid voltage

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IOP Conference Series: Earth and Environmental Science 2018年第1期188卷

作者： C H Gao Y L Kang S H Miao Z W Liu Z H Fan Y L Liu W M Liu T T Zheng M M Zhang State Grid East Inner Mongolia Electric Power Company Limited Electric Power Research Institute Hohhot 010020 China State Key Laboratory of Advanced Electromagnetic Engineering and Technology Hubei Electric Power Security and High Efficiency Key Laboratory School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan 430074 China

A coordinated control method for doubly fed wind power generation system under unbalanced grid voltage is presented in this paper, which can remove the negative effects of unbalanced voltage on the doubly fed induction generator (DFIG) such as the unbalance of stator and rotor current. And the method can suppress the double frequency oscillations of the output active and reactive power. To improve the operating performance, the operation mechanism of DFIG system with a series grid side converter (SGSC) under unbalanced grid voltage is described firstly, and the strategy for series grid side converter aiming at maintaining the stator three phase voltage balance is proposed, and then the stator and rotor currents will keep balanced. Meanwhile, the mathematical model of the parallel grid side converter (PGSC) is analysed under unbalanced grid voltage and the double frequency power control equation is established. According to the control equation, a control strategy based on a proportional resonance (PR) power compensator for the parallel grid side converter is put forward, then the control goal of suppressing the double frequency oscillations of the output active and reactive power of the whole system simultaneously is accomplished, which improves the output quality of the system and ensures the safe operation of the connected grid. The proposed coordinated control strategy in this paper verified by the simulations of a doubly fed wind power generation system model built in PSCAD/EMTDC.

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Power system joint energy and reserve scheduling model considering variable speed pumped hydro storage for mitigating wind curtailment

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IOP Conference Series: Earth and Environmental Science 2019年第1期354卷

作者： T T Zheng Y W Li P W Yang X L Chen R Zheng S H Miao H Ji H R Yin State Grid East Inner Mongolia Electric Power Company Limited Electric Power Research Institute Hohhot 010020 China State Key Laboratory of Advanced Electromagnetic Engineering and Technology Hubei Electric Power Security and High Efficiency Key Laboratory School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan 430074 China

The large-scale integration of wind power brings great challenges to power system secure and economic operation. In order to address this challenge, the variable speed pump storage hydropower plant (VS-PSHP) technology and demand response technology have addressed a lot attention. In this paper, the coordination of the thermal power generator, the wind power plant, the VS-PSHP and multi-type flexible loads are considered, and a day-ahead and real-time coordinated scheduling model are proposed. The proposed model can formulate the generation, contingency reserve and power distribution factor schedules simultaneously. Numerical simulation results indicate that the coordination of VS-PSHP and multi-type flexible loads can increase the system operation economic and mitigating the wind power curtailment. The results also show that the VS-PSHP is good at providing contingency reserve, and the participation of VS-PSHP can lead to a relatively lower total system operation cost compared to the participation of fixed speed pump storage hydropower plant (FS-PSHP).

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Rotation-induced significant modulation of near-field radiative heat transfer between hyperbolic nanoparticles

arXiv

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arXiv 2021年

作者： Hu, Yang Sun, Yasong Zheng, Zhiheng Song, Jinlin Shi, Kezhang Wu, Xiaohu Basic Research Center School of Power and Energy Northwestern Polytechnical University Shaanxi Xi’an710064 China Center of Computational Physics and Energy Science Yangtze River Delta Research Institute of NPU Northwestern Polytechnical University Jiangsu Taicang215400 China Shandong Institute of Advanced Technology Shandong Jinan250100 China School of Energy and Materials Shanghai Polytechnic University Shanghai201209 China School of Electrical and Information Engineering Wuhan Institute of Technology Hubei Wuhan430025 China Centre for Optical and Electromagnetic Research State Key Laboratory of Modern Optical Instrumentation Zhejiang University Hangzhou310058 China Shanghai201209 China

Modulation of near-field radiative heat transfer (NFRHT) with rotated anisotropic hBN and α-MoO3 nanoparticles (NPs) are investigated. The spectral heat power, total heat power and electric field energy density are calculated at different particle orientations. Numerical results show that the modulation factor of the α-MoO3 NPs could be up to ~12000 with particle radius of 40 nm at a gap distance of 200 nm, which is ~ 10-fold larger than the state of the art. Excitation of localized hyperbolic phonon polaritons (LHPPs) in different particle orientations allow for the excellent modulation. The modulation factor of the hBN NPs is 5.9 due to the insensitivity of the LHPPs in the type II hyperbolic band to the particle orientations. This work not only provides a new method to modulate NFRHT in particle systems, but also paves the way to explore radiative heat transfer characteristics of anisotropic media. Copyright © 2021, The Authors. All rights reserved.

关键词： Radiative transfer

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Prospects for Power Systems with High Proportion of Renewable Energy Considering the Coordination of Source-grid

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Journal of Physics: Conference Series 2021年第1期1993卷

作者： Xu Ling Haiyang Yu Yuan Wang Yaowu Wu Shuhao Liang Zhigang Hu Central China Branch of State Grid Corporation of China Wuhan 430074 China China-EU Institute for Clean and Renewable Energy Huazhong University of Science and Technology Wuhan 430074 China State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan 430074 China

In the future, the spatiotemporal distribution of a high proportion of renewable energy will bring unprecedented challenges to power system, and the basic form and operation of power system will have great changes. On the basis of investigating the research status in China and abroad, this paper expounds the scientific problems faced by the planning of Power Systems with High Proportion of Renewable Energy (PSHPRE) considering the coordination of source-grid, and put forward the basic ideas and framework of research from four aspects: overview of the development of PSHPRE, power planning in PSHPRE and coordinated planning of source-grid in PSHPRE. Finally, the prospects for Power Systems with High Proportion of Renewable Energy considering the coordination of source-grid are presented.

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Erratum: “The effects of match circuit on the breakdown process of capacitively coupled plasma driven by radio frequency” [J. Appl. Phys. 131, 153301 (2022)]

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Journal of Applied Physics 2022年第20期131卷

作者： Hao Wu Zhaoyu Chen Shimin Yu Qixuan Wang Xiandi Li Wei Jiang Ya Zhang 1School of Physics Huazhong University of Science and Technology Wuhan 430074 China 2Department of Physics Wuhan University of Technology Wuhan 430070 China 3International Joint Research Laboratory of Magnetic Confinement Fusion and Plasma Physics State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan 430074 China

There are a few typos in the equations of our published article. We apologize for the inconvenience the mistakes may have caused by our careless typing. It shou

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