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International Conference on High Voltage Engineering and Application, ICHVE

作者： Xiong Hao Li Wenjiang Liu Hang Wang Yi Zhang Xiaoxing Maintenance Branch State Grid Chongqing Electric Power Company Chongqing China Hubei Key Laboratory for High-efficiency Utilization of Solar Energy and Operation Control of Energy Storage System Hubei University of Technology Wuhan China

ISBN: (数字)9781728155111

ISBN: (纸本)9781728155128

The SF 6 abatement strategies had received special attention due to the fact that SF 6 has very high global warming potentials and long atmospheric lifetime. The use of degradation method can effectively eliminate the greenhouse effect caused by SF 6 exhaust gas. In this paper, Zr 3 (PO 4 ) 4 , AlPO 4 , NiO and Fe 3 O 4 were used as catalysts to degrade SF 6 gas (the volume ratio of SF 6 was 15% and the background gas was air) at 800 □. The concentration of SF 6 gas was detected by gas chromatograph to obtain degradation rate, the partial degradation products of SF 6 gas were quantitatively analyzed by gaschromatograph-mass spectrometer, and the main products detected were SO 2 F 2 , SOF 2 and SO 2 gas. Comparing the product formation characteristics of four groups of test products when phosphate and metal oxide were used as catalysts, the gas production of SO 2 was the most at the same temperature. When Zr 3 (PO 4 ) 4 and AlPO 4 were used as catalyst, the SO 2 F 2 gas production reached dynamic equilibrium at 31300ppm and 2385ppm respectively after heating for 4h, and the generated SOF 2 gas presented a linear growth. When NiO and Fe3O 4 were used as catalyst, SO 2 F 2 and SOF 2 gases were both linearly increased. When Zr 3 (PO 4 ) 4 was used as catalyst, compared with other catalysts, the amount of SO 2 F 2 produced was the largest. NiO had a good catalytic effect, and the degradation rate of SF 6 gas reached 27.07% within 12h. The main decomposition products were SO 2 F 2 , SOF 2 and SO 2 gas, which could be filtered out by lye, which was of great significance for reducing greenhouse gas caused by SF 6 exhaust gas emissions.

关键词： Catalysis Degradation Heating systems Sulfur hexafluoride Zirconium Iron Maintenance engineering

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Detection and Feeder Identification of the High Impedance Fault at Distribution Networks Based on Synchronous Waveform Distortions

arXiv

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arXiv 2020年

作者： Wei, Mingjie Shi, Fang Zhang, Hengxu Chen, Weijiang Xu, Bingyin Key Laboratory of Power System Intelligent Dispatch and Control Ministry of Education Shandong University Jinan250061 China State Grid Corporation of China School of Electrical and Electric Engineering Shandong University of Technology Zibo255000 China

Diagnosis of high impedance fault (HIF) is a challenge for nowadays distribution network protections. The fault current of a HIF is much lower than that of a normal load, and fault feature is significantly affected by fault scenarios. A detection and feeder identification algorithm for HIFs is proposed in this paper, based on the high-resolution and synchronous waveform data. In the algorithm, an interval slope is defined to describe the waveform distortions, which guarantees a uniform feature description under various HIF nonlinearities and noise interferences. For three typical types of network neutrals, i.e., isolated neutral, resonant neutral, and low-resistor-earthed neutral, differences of the distorted components between the zero-sequence currents of healthy and faulty feeders are mathematically deduced, respectively. As a result, the proposed criterion, which is based on the distortion relationships between zero-sequence currents of feeders and the zero-sequence voltage at the substation, is theoretically supported. 28 HIFs grounded to various materials are tested in a 10kV distribution network with three neutral types, and are utilized to verify the effectiveness of the proposed algorithm. Copyright © 2020, The Authors. All rights reserved.

关键词： Fault detection

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Coordinated Dispatching and Frequency control Strategy of power systems with Large Scale Wind power Penetration

Coordinated Dispatching and Frequency Control Strategy of Po...

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Chinese Automation Congress (CAC)

作者： Jianhua Zhang Rui Shan Fei Xu Bo Hu Guiping Zhou Guolian Hou Congzhi Huang State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University Beijing China School of Control and Computer Engineering North China Electric Power University Beijing China Tsinghua University Beijing China State Grid Liaoning Electric Power Supply Co. Ltd. Shenyang China

ISBN: (数字)9781728176871

ISBN: (纸本)9781728176888

In this paper, a coordinated dispatching and frequency control strategy is presented for wind turbines (WTs) participating in frequency regulation from three levels. Firstly, the coordinated dispatching and frequency control strategy among multi-source power generation systems is given with the aid of the wind power installed capacity penetration rate; Secondly, the coordinated distribution strategy among the wind farms is presented by combing the incremental active power reference with parameters tuning method; Thirdly, the coordinated control is investigated by integrating droop control, inertia control and de-load control for each WT. simulation results demonstrate that the proposed coordinated dispatching and frequency control strategy can obtain better frequency regulation performance for power systems with large scale wind power penetration.

关键词： Frequency control Wind turbines Wind power generation Dispatching Wind speed Wind farms Rotors

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A review of bearing fault diagnosis for wind turbines

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IOP Conference Series: Earth and Environmental Science 2021年第1期675卷

作者： Bing Liu Baixin Liu Qingbin Dai Huaping Liu AnHui JEP New Energy Co LTD AnHui 230000 China Key Laboratory of Modern Power System Simulation and Control & Renewable Energy Technology Ministry of Education (Northeast Electric Power University) Jilin 132012 China

Bearings are the core components of the wind turbine's mechanical transmission system, but the bearings of wind turbines are prone to wear and failure during vibration, and it is often difficult to determine the fault-bearing status and fault location. Therefore, the monitoring and fault diagnosis of wind turbine bearing status are very necessary. This paper introduces the types of bearings of wind turbines and common faults of bearings, analyzes from the aspects of bearing vibration data and supervisory control and data acquisition (SCADA) systems, summarizes the existing fault diagnosis methods and systems of wind turbine bearings, and points out the basics of these methods thought. Finally, the research focus of future bearing fault diagnosis is elaborated.

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Synthesis of Agomelatine by One-pot Catalytic Hydrogenation and Acetylation with NiO

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Journal of Wuhan University of Technology(Materials Science) 2019年第2期34卷 453-458页

作者： YU Zhijun CHENG Zhengzai XIE Cong ZENG Sheng DENG Haiying LIU Panpan HU Hai LI Guangyao DING Ling Mario Gauthier LI Shiqian School of Medicine Wuhan University of Science and TechnologyWuhan 430065China Non-power Nuclear Technology Research and Development Center Hubei University of Science and TechnologyXianning 437100China The State Key Laboratory of Refractories and Metallurgy(Wuhan University of Science and Technology) Wuhan 430081China Coal Conversion and New Carbon Materials Hubei Key Laboratory School of Chemistry and Chemical EngineeringWuhan University of Science and TechnologyWuhan 430081China Key Laboratory of Measurement and Control System for Offshore Environment Fuqing Branch of Fujian Normal UniversityFuqing 350300China

Nano-NiO and bulk NiO were prepared from Ni(AC)_2·4 H_2O by coordination precipitation using aqueous ammonia and by a solid state reaction, respectively. The nickel oxide particles were characterized by X-ray Diffraction(XRD) and scanning electron microscopy(SEM). The results indicate that nano-sized NiO has a crystal phase with a standard face-centered cubic lattice structure, with a mean particle diameter of about 10 nm. The evaluation of the activity of nickel oxide nanoparticles in the catalytic hydrogenation of 7-methoxy-1-naphthylacetonitrile was carried out. The results demonstrate the efficient synthesis of the title compound by a one-pot catalytic hydrogenation and acetylation with NiO. The NiO nanoparticles displayed superior catalytic activity in the synthesis of agomelatine in the one-pot *** total yield of agomelatine is over 81.8% with a purity of 99.2%, as determined by HPLC. The structure of agomelatine was confirmed by IR, MS, and 1 H NMR analysis.

关键词： nano-NiO homogeneous precipitation method catalytic hydrogenation agomelatine N-[2-(7-Methoxy-1-naphthyl)ethyl]acetamide 7-Methoxy-1-naphthylacetonitrile

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Dynamic Security Assessment Method of power system Based on Improved XGBoost

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Journal of Physics: Conference Series 2021年第1期1750卷

作者： Jihong Ren Key Laboratory of Modern Power System Simulation and Control and Renewable Energy Technology Ministry of Education Northeast Electric Power University Jilin Jilin132012 China Department of Electrical Engineering Northeast Electric Power University Jilin Jilin 132012 China

With the deployment of wide-area measurement systems (WAMS) equipment, dynamic security assessment (DSA) based on artificial intelligence (AI) has more and more advantages. For the power system, the number of transient stable cases is much larger than that of unstable cases, which leads to insufficient learning of unstable cases and affects the evaluation effect of the model. In addition, during the stability assessment process of the power system, the misjudgment cost of unstable case is much higher than that of stable case. Based on the above two points, we proposed a DSA method of power system based on improved XGBoost. The proposed method introduces the weight adjustment factor into the loss function to balance the quantity variance of two type cases and the difference of misjudgment cost, which greatly reduces the misjudgment rate of unstable samples. The test results on IEEE 16-machine 68-bus test system and IEEE 50-machine 145-bus test system show that the proposed method can have higher recognition of the unstable samples and can be applied to DSA.

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Improved active damping control strategy and closed-loop parameter design for LCL grid-connected inverter

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Journal of Physics: Conference Series 2021年第1期2030卷

作者： Qi Chen Hongbo Liu Qingxiang Hao Yikun Yin Yuanhong Li Key Laboratory of Modern Power System Simulation and Control and Renewable Energy Technology Ministry of Education Northeast Electric Power University Jilin 132012 China Zaozhuang Power Supply Company State Grid Shandong Electric Power Company Zaozhuang 277000 China Changchun Institute of Technology ChangChun 130012 China

In this paper, an active damping control strategy based on capacitance and voltage feedback is proposed to solve the resonance problem of three-phase LCL inverter grid-connected system. To solve the problem that the parameters of active damping control strategy are complicated and need to be adjusted repeatedly, a parameter design method is proposed in this paper, which is simple to implement and does not need to be adjusted repeatedly. Finally, the effectiveness of the control strategy and parameter design method is verified by experiments.

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Investigating the transient torque of turbo-generators in a power system integrating wind farms

Investigating the transient torque of turbo-generators in a ...

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8th Renewable power Generation Conference (RPG 2019)

作者： Bowen Yang Gangui Yan Xiaorong Xie Yanhui Wang Jian Tang Key Laboratory of Modern Power System Simulation and Control & Renewable Energy Technology Ministry of Education Northeast Electric Power University Jilin China State Key Laboratory of Power System Department of Electrical Engineering Tsinghua University Beijing China State Grid East Mongolia Electric Power Supply Co. Ltd. Hohhot China

ISBN: (数字)9781839531248

ISBN: (纸本)9781839531255

The renewable energy sources connected to the grid will cause the power system to oscillate and even affect neighbouring turbo-generators. For example, the wind turbines and their converter control systems may cause shaft torsional vibration in the steam turbine units, which affects the safety of the system. Therefore, it is of significance to investigate the transient torque of turbo-generators in a power system integrating wind farms. This paper takes a power plant in Inner Mongolia area of China as the case, the power of which is transmitted via the AC/DC hybrid power system with wind and thermal power. A typical equivalent system model of the wind-thermal-bundled access network is established firstly. Consider setting the fault on the line with series capacitor compensation and observe units' torque variation. Then the impact on sub-synchronous resonance (SSR) characteristics from many factors was investigated through the time-domain simulation, including the unit combination mode (including the long-term accessed DFIGs condition), the fault type and position, the system equivalent impedance, the fault starting/clearing time and the mechanical mutual damping coefficient of shafting, etc. Finally, the influence of each factor on transient torque is summarized, and the inner associations between the shaft torsional vibration in the turbo-generators and the converter-based wind turbines are clarified.

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Prediction model of multi-step attack

Prediction model of multi-step attack

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International Conference on Information Science and control Engineering (ICISCE)

作者： ZeKe Li Zhilin Duo ZeWen Chen Zilun Zhao Ye Liang FUJIAN Electric Power Corporation BeiJing China Nari Group Corporation Beijing Kedong Electric Power Control System Co.Ltd. BeiJing China State Key Laboratory of Networking and Switching Technology Beijing Beijing University of Posts and Telecommunications Beijing China

There are many security monitoring devices running in the state gird. The security monitoring devices can detect the alerts. Correlations between these alerts are existed. A complete multi-step attack event can be divided into many stages, the serious attack events always occurs in the later stage in a complete attack. We can make better defense when facing attack if we predict the next possible attack event. This paper proposed a multi-step attack prediction model. The attack events in state gird are transformed into the original dataset, which can be considered as the input of prediction model. By using this model, state gird security personnel can use prediction model to take preventive measures from being attacked. Experiments show that the recall rate and accuracy rate of this prediction model have reached 84. 90% and 84. 91%

关键词： Information science Machine learning algorithms Correlation Machine learning Forestry Predictive models Prediction algorithms

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Sources of atmospheric glyoxal and methylglyoxal in Beijing and its impact on wintertime secondary organic aerosol formation

Sources of atmospheric glyoxal and methylglyoxal in Beijing ...

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第二十四届大气污染防治技术研讨会

作者： Xionghui Qiu Shuxiao Wang Qi Ying Lei Duan Jia Xing Jingyuan Cao Di Wu Xiaoxiao Li Chengzhi Xing Xiao Yan Cheng Liu Jiming Hao MOE Key Laboratory of Resources and Environmental System Optimization College of Environmental Science and Engineering North China Electric Power University State Key Joint Laboratory of Environmental Simulation and Pollution Control School of Environment Tsinghua University State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex Zachry Department of Civil Engineering Texas A&M University College Station School of Earth and Space Sciences University of Science and Technology of China National Engineering Research Center of Urban Environmental Pollution Control Beijing Municipal Research Institute of Environmental Protection Department of Precision Machinery and Precision Instrumentation University of Science and Technology of China

Atmospheric glyoxal(GLY) and methylglyoxal(MGLY) are key precursors of secondary organic aerosol(SOA). However, anthropogenic emissions of GLY and MGLY and their contribution to surface GLY and MGLY concentrations, as well as the secondary organic aerosol(SOA) formation, are not well quantified. By developing an emission inventory of anthropogenic GLY and MGLY and improving Community Multiscale Air Quality Model(CMAQ) with SOA formation from irreversible surface uptake of GLY and MGLY, as well as a precursor-origin resolved technique, we quantified the source contributions of GLY and MGLY and their impact on wintertime SOA formation in Beijing, China. The total emissions of GLY and MGLY in Beijing in 2017 are 1.1×10～4 kmol and 7.0×10～3 kmol, respectively. Anthropogenic primary emissions are found to be the dominant contributor to GLY and MGLY concentrations(～74% for GLY and ～63% for MGLY). Anthropogenic primary emissions of GLY and MGLY contributes to 30% of GLY/MGLY SOA daily average concentration and accounts for up to 45% of nighttime GLY/MGLY SOA. The study suggests that the anthropogenic GLY and MGLY emissions, mainly from gasoline vehicles and cooking, are important for SOA formation and shall be strictly controlled in Chinese megacities.

关键词： SOA Sources of atmospheric glyoxal and methylglyoxal in Beijing and its impact on wintertime secondary organic aerosol formation

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