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7th IEEE International Conference on High Voltage Engineering and Application, ICHVE 2020

作者： Yang, Feng Sun, Peng Wang, Dong Tang, Chao Zhou, Qu Du, Lin College of Engineering and Technology Southwest University Chongqing400716 China Electric Power Research Institute of State Grid Henan Electric Power Company Henan450000 China State Key Laboratory of Power Transmission Equipment System Security and New Technology Chongqing University Chongqing400044 China

ISBN: (纸本)9781728155111

As a non-intrusive measurement method, frequency domain spectroscopy (FDS) is widely used to diagnose the global defects (such as aging and dampness) of the insulation body in power equipment. However, the FDS method can only map the holistic dielectric response (DR) characteristics of composite oil-impregnated-paper (OIP) insulation that usually comprises both the insulation paper and oil. Under irregular insulation structure, the DR of each dielectric cannot be simply distinguished, which is unconducive to detect the insulation weakness therein. In this paper, a novel inverse problem model to analyze the separate DR of each dielectric within a compound insulation structure is proposed. Built on the modified Cole-Cole formula, the inverse problem is solved by an optimization process which combines the finite element method and GA-LMA numerical algorithm, and the dielectric variables of insulating oil and paper are back-calculated respectively. By comparing the error of the measured and reconstructed FDS traces, it is evidenced that the proposed model of DR inverse problem and its solution method are suitable for FDS measurements, which signifies new indications for refined state evaluation of OIP insulation by enabling inspecting the separate DR information of each dielectric within a real-life complex insulation structure. © 2020 IEEE.

关键词： Inverse problems

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An New Method for Detecting Harmonic Currents

An New Method for Detecting Harmonic Currents

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2020 International Conference on Ubiquitous power Internet of Things, UPIOT 2020 and 4th International Symposium on Green Energy and smart grid, SGESG 2020

作者： Chen, Xianfeng Guo, Lin Gong, Jie Huizhou Power Supply Bureau Guangdong Power Grid Corporation Huizhou China State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan China

The widespread use of power electronics has led to increasing problems with harmonics in power systems. The ip-iq detection method is a common method to detect harmonics. If there is a symmetry of the three phases of the power system, the ip-iq detection method can have very large errors in detecting the harmonic current. To solve this problem, an new method for detecting harmonic currents is proposed in this paper. The method solves the phase between the positive sequence voltage of each phase and the actual voltage by using the delay method to obtain the positive sequence fundamental signal of the fundamental current error problem. The simulation was then carried out using MATLAB/SIMULINK, and the simulation results confirmed the method still accurately detects harmonic currents in all cases. Therefore, this method is of great research importance for the elimination of harmonics. © Published under licence by IOP Publishing Ltd.

关键词： Harmonic analysis

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Experimental study on temperature control of cable tunnel fire under the combined effect of fine water mist and mechanical ventilation

Electrical Materials and Applications

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Electrical Materials and Applications 2024年第3-4期1卷

作者： Hui Zhu Jun Ji Jingkai Nie Yu Xia Sichuan Fire Research Institute of MEM Chengdu Sichuan China Global Energy Interconnection Research Institute Co. Ltd Future City for Science and Technology Beijing China State Key Laboratory of Advanced Power Transmission Technology State Grid Smart Grid Research Institute Co. Ltd Beijing China Institute of Fluid Science Tohoku University Sendai Japan

Electricity is an important energy supply for industry, and long-distance transmission in China mainly relies on cable tunnels, while cable tunnel fires occur frequently. A 1:1 scale tunnel model with a length of 20 m, a width of 2.5 m, and a height of 2.5 m was used to conduct experimental research on the temperature field of the ceiling of a high-voltage fine water mist suppression cable tunnel. The article conducted experimental research on parameters, such as nozzle pressure, nozzle position, and longitudinal ventilation speed in high-pressure water mist systems using n-hexane as the ignition source. The results indicate that the high-pressure water mist system can effectively reduce the ceiling temperature during cable tunnel fires. When the mechanical smoke evacuation system is activated, it leads to a reduction in the overall temperature within the tunnel. When the mechanical smoke extraction system is integrated with the high-pressure water mist system, therefore, it is feasible to integrate the high-pressure water mist system with the mechanical smoke exhaust system in engineering applications.

关键词： cable tunnel fire mechanical ventilation temperature field thermal insulation water mist

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EXCELLENT VARISTOR CALCIUM COPPER TITANATE COMPOSITES TAILORED BY INTERFACE ENGINEERING 22

EXCELLENT VARISTOR CALCIUM COPPER TITANATE COMPOSITES TAILOR...

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22nd International Symposium on High Voltage Engineering, ISH 2021

作者： Tang, Zhuang Xie, Pengkang Fu, Zhiyao Ning, Kai State Key Laboratory of Disaster Prevention and Reduction for Power Grid Transmission and Distribution Equipment Changsha410000 China College of Electrical and Information Engineering Hunan University Changsha410082 China School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan430074 China School of Electric al & Information Engineering Changsha University of Science & Technology Changsha410114 China

ISBN: (纸本)9781839536052

In this work, based on former results, we extend on study of CaCu3Ti4O12 based composites. Since yttrium doped CaCu3Ti4O12 is able to enlarge the grain boundary resistance and suppress the dielectric loss simultaneously, Y is considered as an excellent doping element to develop optimized dielectric and electrical CCTO based ceramics. For 0.5Ca0.5Y0.33Cu3Ti4O12-0.5SrCu3Ti4O12, breakdown field is as high as 35.82 kV·cm-1 and nonlinear coefficient is 14.65 in the current range of 0.1-1 mA. The withstand voltage of single grain boundary raises from 4 to 24 V with higher Y content. Moreover, relaxation process is systematically studied through electric modulus spectra and activation energy calculation. CaCu3Ti4O12 composite system composed of Y-doped CaCu3Ti4O12 and SrCu3Ti4O12 is ascribed as a reasonable system to improve varistor properties via interface engineering. © 2021 The Institution of Engineering and technology.

关键词： Copper compounds

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An Efficient Qr-Bimgm Model for Probabilistic Pv power Forecasting

SSRN

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SSRN 2022年

作者： Ma, Xiping Du, Haodong Wang, Kaiyan Jia, Rong Wang, Songkai School of Electrical Engineering Xi’an University of Technology Xi'An710048 China Electric Power Research Institute State Grid Gansu Electric Power Company Gansu Province 730050 China Key Laboratory of Smart Energy in Xi’an Xi’an University of Technology Xi'An710048 China Shaanxi Electric Power Comprehensive Energy Engineering Technology Center Xi'An710048 China

The inherent volatility and randomness of PV output has posed a severe danger to the safe and stable functioning of power systems in recent years, as grid-connected PV capacity has increased. Short-term probabilistic PV power predictions can provide power system decision-makers with more detailed information. A novel probabilistic PV power forecast model based on the fuzzy C-mean clustering algorithm and the QR-BiMGM model is proposed in this research. The MGM (Minimal Gated Memory) model reduces training time while enhancing prediction accuracy by simplifying the neuron structure. The model's data mining capabilities is further enhanced by the bidirectional propagation structure. To provide probabilistic prediction results, the Quantile Regression (QR) model is employed to integrate the BiMGM model. Under diverse weather conditions, a comparative analysis using actual measurement data with four benchmark models shows that the proposed model has higher prediction performance and good generalisation potential. The QR-BiMGM model's mean integrated interval evaluation metric WC is 31.38 percent lower than QR-MGM, 50.21 percent lower than QR-LSTM, 44.85 percent lower than QR-BiLSTM, and 44.83 percent lower than QR-GRU, according to simulation results. The mean probabilistic prediction evaluation metric CRPS of the QR-BiMGM model is 3.5 percent lower than that of QR-MGM. 3.6 percent lower than QR-MGM, 20.91 percent lower than QR-LSTM, 17.56 percent lower than QR-BiLSTM, and 20.36 percent lower than QR-GRU. In addition, the probability density function based on the conditional quantile of PV power is estimated using a modified kernel density estimation approach. © 2022, The Authors. All rights reserved.

关键词： Solar cells

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Calculation model of aerodynamic parameters for iced wind turbine

Calculation model of aerodynamic parameters for iced wind tu...

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22nd International Symposium on High Voltage Engineering (ISH 2021)

作者： Z. Yu L. Shu H. Li Q. Hu X. Jiang State Key Laboratory of Power Transmission Equipment & System Safety and New Technology School of Electrical Engineering Chongqing University Chongqing China State Grid Tianfu New District Power Supply Company Chengdu Sichuan China

Wind turbines at high altitudes suffer icing harm frequently in winter, and the aerodynamic profile will be destroyed which leads to output power loss. Studying the aerodynamic parameters could provide references in icing prediction or anti-icing. 3D CFD simulation is a common method to solve these issues, but it consumes lots of computational resources and time. In this paper, a more simpler calculation model of aerodynamic parameters for iced wind turbine, which combining 2D CFD simulation method and blade element momentum, is proposed. The accuracy of this model is verified by comparing the calculated and measuring output power results. According to this model, axial inducing factor a , tangential inducing factor b , tangential force P N and normal force P T are calculated under different wind velocity as well. The results show that the max factor a appears near rotor tip while the max factor b appears near rotor root. Furthermore, with the increasing of wind velocity, P N and P T show an increasing trend. By comparing the normal force on blade under icing and clean condition, results show that, with wind velocity increasing, the difference of normal force will get larger and the max difference appears near the rotor tip.

关键词： aerodynamics blades computational fluid dynamics ice rotors wind tunnels wind turbines

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Corrigendum to “Hierarchical evaluation framework for coupling effect enhancement of renewable energy and thermal power coupling generation system” [Int. J. Electr. power Energy Syst. 146 (2023) 108717]

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International Journal of Electrical power & Energy Systems 2024年 158卷

作者： Yao Zou Qianggang Wang Bo Hu Yuan Chi Guiping Zhou Fei Xu Niancheng Zhou Qinqin Xia State Key Laboratory of Power Transmission Equipment Technology School of Electrical Engineering Chongqing University China State Grid Liaoning Electric Power Company Limited Shenyang Liaoning China State Key Laboratory of Control and Simulation of Power System and Generation Equipment Tsinghua University Beijing China

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Optimal Configuration of ESS and SVG for the Coordinated Improvement of power Quality in Low Voltage Distribution Network with high Penetration PV

Optimal Configuration of ESS and SVG for the Coordinated Imp...

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power and Electrical Engineering (ACPEE), 5th Asia Conference on

作者： Chunxue Zhao Bo Zhang Lu Zhang Wei Tang Meng Tan Yaqiong Li Guoqiang Su College of Information and Electrical Engineering China Agricultural University Beijing China State Key Laboratory of Advanced Power Transmission Technology Global Energy Internet Research Institute Co. Ltd Beijing China State Grid Shandong Electric Power Research Institution China

With the continuous increase of renewable energy such as photovoltaic integrated into the low-voltage (LV) distribution network, high power losses, voltage violations and three-phase unbalance problems may happen due to the reverse power flows and randomness of PV power output. SVG and ESS have more ideal effects when dealing with the above power quality problems in LV distribution network. In order to improve power quality with minimum cost and achieve a coordinated configuration, this paper proposes a collaborative management method based on a bi-level programming model to optimize the configuration of ESS and SVG. By comparing the three configuration methods, the validity of the proposed model and algorithm is verified. Coordinated configuration of ESS and SVG is more economical and can effectively suppress the over-limit voltage, reduce the three-phase unbalance degree and network losses in distribution network with high penetration PV.

关键词： Photovoltaic systems Low voltage Renewable energy sources Simulation power quality Distribution networks Programming

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Fabry-Perot Interference Based Fiber Optic Sensing Method for Partial Discharge and Fast Temperature Change in power Transformers

Fabry-Perot Interference Based Fiber Optic Sensing Method fo...

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advanced Electrical Equipment and Reliable Operation (AEERO), International Conference on

作者： Zhixian Zhang Weigen Chen Fan Liu Kejie Wu Yuxuan Song Jiali Lei Tianhe Yang State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University Chongqing China State Grid Hubei Electric Power Research Institute Wuhan Hubei China Chongqing University Chongqing China

ISBN: (纸本)9781665402651

To simplify the installation and wiring of sensors inside transformers and the structure of light source and demodulation system of fiber optic sensing system, a Fabry-Perot (F-P) interference-based fiber optic sensing method for partial discharge and fast temperature change in power transformers is proposed. The joint sensing of partial discharge and oil temperature change is realized based on narrowband laser and photodetector. A fiber optic F-P ultrasonic sensor with resonant frequency at 153 kHz was designed using a vibration model of a single-sided contact diaphragm with liquid to achieve sensing of 191.23 pC in oil. Based on the same sensor, a temperature change detection method based on the DC component of the F-P cavity output light intensity was investigated. The experimental results show that the DC component of the sensor output light intensity will periodically appear as a Gaussian pulse reversed along the X-axis which will pass through a minimum point when the temperature changes. The faster the temperature changes, the more times the DC component passes the minimum point in a period of time. Therefore, the number of the DC component of the sensor's output light intensity passing the minimum point in a period of time can be counted to reflect the rapidity of the internal oil temperature change of the transformer.

关键词： Temperature sensors Optical fibers Partial discharges Optical fiber sensors Oils Resonant frequency Oil insulation

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Optimal Carbon Capture, Utilization and Storage Planning for Multi-Energy System

Optimal Carbon Capture, Utilization and Storage Planning for...

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Chinese Control Conference (CCC)

作者： Aoyu Hu Da Xu Menglu Gao School of Automation China University of Geosciences Wuhan China Hubei Key Laboratory of Advanced Control and Intelligent Automation for Complex Systems Wuhan China Engineering Research Center of Intelligent Technology for Geo-Exploration Ministry of Education Wuhan China DC Company of State Grid Hubei Electric Power Co. Ltd. Yichang China

In response to the national dual carbon policy, carbon capture, utilization and storage (CCUS) are currently attracting much attention. This paper proposes optimal CCUS planning for multi-energy system. In this multi-energy system, transmission network and natural gas network are coupled via conversion and storage devices in the energy hubs. The CCUS planning is formulated based on a source-sink matching method to analyze the CO2 capture points, CO 2 storage points and CO 2 transportation routes. Furthermore, the original CCUS planning problem is reformulated as a mixed integer second order cone programming (MISOCP) and subsequently solved to guarantee a satisfactory convergence performance. Numerical studies on an urban multi-energy system are implemented to verify the effectiveness and superiority of the proposed methodology over conventional scheme.

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