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The 16th IET International Conference on AC and DC power transmission (ACDC 2020)

作者： N. Zhang X. Hu X. Wei C. Gao L. Chen W. Wen Global Energy Interconnection Research Institute Co.Ltd. State Key Laboratory of Advanced Power Transmission Technology Beijin China Tianjin University Key Laboratory of Smart Grid of Ministry of Education Tianjin China

With features of negligible operating losses and low construction cost, mechanical direct current circuit breakers (DC-CBs) with auto-reclosing function have promising application prospects in DC system with overhead lines to ensure its reliability, flexibility and stability. In order to realize reliable current interruption and auto-reclosing of mechanical DC-CBs with current commutation drive circuit (CCDC), novel operating strategy for mechanical DC-CBs with CCDC during the whole process of dealing with DC faults, including current interruption sub-process and auto-reclosing sub-process, is proposed first. Then, operating characteristic of mechanical DC-CB with CCDC and its equivalent circuit during different stages of the whole process of dealing with faults are analyzed, and impacts of capacitor (C) in DC circuit breaker on transient interruption voltage of ultra-fast mechanical switch, characteristics of residual current, and reclosing current are analyzed. Finally, based on impacts of capacitor, design criterion of capacitor in accordance with DC system parameters are proposed. In the end, case study is carried out in PSCAD/EMTDC to verify the theoretical analysis and the design criterion of capacitor.

关键词： power overhead lines circuit breakers driver circuits equivalent circuits capacitor switching switching transients power system faults power system reliability

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Numerical Stability and Compensation Method for Equivalent Controlled Source in Electromagnetic Transient Simulation

Numerical Stability and Compensation Method for Equivalent C...

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2019 IEEE PES Innovative smart grid Technologies Asia, ISGT 2019

作者： Gao, Lu Ji, Feng Yan, Heming Lin, Chang Pang, Hui Li, Jihong State Key Laboratory of Advanced Power Transmission Technology Beijing Key Laboratory of DC grid Technology and Simulation Global Energy Interconnection Research Institute Co. Ltd Beijing China State Grid Zhejiang Electric Power Co. Ltd Hangzhou China

ISBN: (纸本)9781728135205

In electromagnetic transient simulation, equivalent controlled source is usually used as an alternative of the original circuit element, such as a controlled voltage source to replace the modular multilevel converter(MMC). Since a time-step delay between the control and circuit system solution, there may be numerical stability problem. By deducing the delay differential equation and calculating its characteristic values, the causes of numerical instability are explained. Finally the numeric compensation method to solve the numerical stability problem is proposed by studying the delay function through Taylor's series and Laplace transformation. © 2019 IEEE.

关键词： Time delay

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Research on the Application of Digital Twin Technique in High Voltage Cable

Research on the Application of Digital Twin Technique in Hig...

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power and Energy Engineering (ICPEE), International Conference on

作者： Weisheng He Zhaoguo Wu Xiao Ren Hong Xiang Xin Gong Jiuhong Mou Chao Ma State Grid Chongqing Electric Power Research Institute State Grid Chongqing Electric Power Company Chongqing China State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University Chongqing China State Grid Changshou Power Supply Company State Grid Chongqing Electric Power Company Chongqing China

ISBN: (数字)9781728191256

ISBN: (纸本)9781728191263

High voltage cables are directly related to urban power transmission and distribution. With the proposal and development of the concept called ubiquitous power Internet of things (UPIOT), the holographic state perception techniques of power cables will be further promoted. In order to use the obtained data information more efficiently and scientifically, this paper introduces digital twin (DT) technique into power cable field and explores the application of this advanced technique. This paper firstly introduces the meaning, technical system and key elements in DT model. Then the application scenarios of DT driven technical frameworks of high voltage cable design, production and operating maintenance are described.

关键词： Optical fiber cables High-voltage techniques Data models power cables Communication cables Maintenance engineering Monitoring

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Lightning Trip Warning Based on GA-BP Neural Network technology

Lightning Trip Warning Based on GA-BP Neural Network Technol...

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HVDC (HVDC), International Conference on

作者： Gu Su Tang Chongwang Deng Zhiyong Wang Zhenyu Wang Jia Feng Yongkun State Grid Hunan Power Transmission Maintenance Company Changsha China Hunan Province Key Laboratory of Intelligent Live Working Technology and Equipment (Robot) State Grid Hunan Power Transmission Maintenance Company Changsha China

ISBN: (数字)9781728175935

ISBN: (纸本)9781728175942

Due to the complex operation environment of transmission lines and many factors affecting lightning trip, it is difficult to realize real-time warning of lightning trip of transmission lines. This paper presents a new real-time warning method for lightning trip based on the combination of lightning location system, transmission line data and GA-BP neural network technology. Firstly, the factors affecting line tripping are determined and input data are preprocessed. Then, a lightning trip prediction model based on GA-BP neural network is established. The total number of lightning trips can be predicted by summing up the results of all the intervals of the line to be warned. Finally, according to the classification standard of early warning, the lightning trip warning of the whole line is realized. The example shows that the correct classification rate is 80%, the accuracy rate is 86.67%, the false alarm rate and the leakage alarm rate are 23.53% and 13.33% respectively. The performance index of the model is ideal, so the model has a good prediction effect for the real-time lightning trip warning of transmission lines.

关键词： Lightning power transmission lines Real-time systems Poles and towers Genetic algorithms Biological neural networks power transmission

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A novel method based on dynamic extinction angle of thyristor to mitigate commutation failure for HVDC 16

A novel method based on dynamic extinction angle of thyristo...

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16th IET International Conference on AC and DC power transmission, ACDC 2020

作者： Kou, Longze Mi, Zhiwei Huang, Xiaojing State Key Laboratory of Advanced Transmission Technology Global Energy Interconnection Research Institute Ltd. Changping District Beijing China Beijing Key Laboratory of DC Grid Technology and Simulation Global Energy Interconnection Research Institute Ltd Changping District Beijing China School of Electrical and Electronic Engineering North China Electric Power University Changping District Beijing China

ISBN: (纸本)9781839533914

Commutation failure is one of the critical problems for the HVDC transmission system. According to the theoretical analysis, the characteristics of the dynamic minimum extinction angle of the thyristor can be obtained. Considering the effect of the system operation conditions on the minimum extinction angle of the thyristor, a dynamic compensation method is proposed, which aims to mitigate the commutation failure of the HVDC transmission system. A simulation model based on CIGRE HVDC standard test system is built in PSCAD/EMTDC. The control performance of the proposed compensation method is verified by carrying out simulations under different fault scenarios. Simulation results prove that the proposed compensation method, to some extent, has the ability to mitigate the consequential commutation failure under single-phase fault and three-phase fault. Therefore, the fault recovery characteristics and the reliability of HVDC transmission system can be effectively improved. © 2020 Institution of Engineering and technology. All rights reserved.

关键词： Electric commutation

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Research on the corrosive effect of inactive sulfur on oil-paper insulation 7

Research on the corrosive effect of inactive sulfur on oil-p...

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

作者： Gao, Sihang Li, Jiajun Ke, Tingjing Liu, Yang Ding, Dong Key Laboratory of Industrial Internet of Things and Networked Control Ministry of Education Chongqing University of Posts and Telecommunications Chongqing China State Grid Chongqing Electric Power Company Chongqing Chongqing China Baoding Electric Power Corporation Baoding China State Key Lab. of Transmission Distribution Equipment and Power System Safety and New Technology Chongqing University Chongqing China

ISBN: (纸本)9781728155111

Sulfur corrosion induced by active sulfur has been proved to significantly decrease the insulation performance of oil-immersed equipment. In order to protect the oil-paper insulation from sulfur corrosion, active sulfur is cleared in the refining process of crude oil. Some inactive sulfur with high-efficiency antioxidant is still retained in the mineral oil to improve the oxidation stability of oil, such as thiophenic compounds. However, the corrosive effect of inactive sulfur on the oil-paper insulation has not yet clear. Therefore, thiophene that is the largest content of sulfide in the insulating oil was selected as the research object, a series of accelerated thermal ageing experiments of oil-paper without and with thiophene under the different high temperature were conducted, scanning electron microscope equipped with an energy-dispersive X-ray spectrometer (SEM/EDX) and inductively coupled plasma atomic emission spectrometry (ICP-AES) were used to characterize the corrosion degree of oil-paper insulation. The results show that no corrosive deposit was observed on the surface of oilpaper insulation without thiophene even at very high temperature, while a few corrosive deposit was accumulated on the surface of oil-paper insulation with 500 mg/kg thiophene. The corrosion degree of oil-paper insulation with thiophene had an uptrend as the increase of temperature (130°C-180°C), preliminarily indicating that thiophene may be activated in the oil-paper system under the action of overheating fault of oil-immersed transformer and posed a corrosion threat to oil-paper insulation. © 2020 IEEE.

关键词： Scanning electron microscopy

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Numerical Simulation of Corrosion Characteristics of Copper Grounding grid Materials in Extreme Weather

Engineering Reports

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Engineering Reports 2025年第6期7卷

作者： Hongxia Wang Yang Yang Puzhi Zhao Jie Xu Shenbing Hua State Grid Xinjiang Company Limited Electric Power Research Institute Urumqi Xinjiang China Xinjiang Key Laboratory of Operation and Detection Technology for Power Transmission & Transformation Equipment in Extreme Environment Urumqi Xinjiang China Company of State Grid Xinjiang Electric Power Urumqi Xinjiang China Meteorological Service Center of Xinjiang Uygur Autonomous Region Urumqi Xinjiang China China Electric Power Research Institute Beijing China

This study investigates the corrosion characteristics of copper grounding grid materials in extreme weather conditions through numerical simulation, providing essential corrosion data for substation operation and maintenance. According to the corrosion principle of copper grounding grid materials, three typical soil environments were selected: alkaline laterite soil, acidic soil, and acidic sediment. The physicochemical properties of these soils were determined through redox potential measurements. Subsequently, the electrochemical parameters of the copper grounding grid materials were calculated using weak polarization and electrochemical impedance spectroscopy to derive their corrosion rates. Using ANSYS finite element software, a corrosion model was established with the corrosion rates of the copper grounding grid materials and the physicochemical properties of the soil as inputs. This model simulates the corrosion behavior under different conditions, including extreme weather, varying soil types, and moisture content levels. The numerical simulation results demonstrate that higher moisture content in all three soil types leads to increased corrosion rates of the copper grounding grid materials. Specifically, at a water-to-soil ratio of 1:1, the self-corrosion current density of the materials exhibits a time-dependent increase across all tested soil environments.

关键词： copper grounding grid corrosion characteristics of materials extreme weather finite element analysis numerical simulation water content

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Research on a Bluetooth Low Energy Warning Method 2

Research on a Bluetooth Low Energy Warning Method

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2nd International Conference on Artificial Intelligence and Computer Science, AICS 2020

作者： Long, Yan Chen, Yongli Xiao, Deyong Li, Zheng Hou, Tianpeng Zhang, Zhiwei State Grid Key Laboratory of Power Industrial Chip Design and Analysis Technology Beijing Smart-Chip Microelectronics Technology Co. Ltd. Beijing100192 China Beijing Engineering Research Center of High-Reliability Ic with Power Industrial Grade Beijing Smart-Chip Microelectronics Technology Co. Ltd. Beijing100192 China

With the development of society, intelligent terminal equipment is used more and more widely. The use of intelligent terminals to locate children's position, to ensure that children are in a safe and controllable range, is more favored by parents. But now the smart watch needs to install the mobile phone card, which depends on the mobile phone traffic to locate, and the cost is relatively high. This paper proposes a Bluetooth low energy warning method to solve this problem. The distance between the two devices is calculated by the signal strength indication value received by the intelligent terminal, and then compare the preset received signal strength indication value with the received signal strength indication value, as well as the preset distance value and the calculated distance value of the two devices. When the received signal strength indication value is less than the preset value or the distance between the devices exceeds any of the preset values, the wireless device and the intelligent terminal will send an alarm at the same time to remind the two sides wearing the intelligent terminal and the Bluetooth device that the distance between the two sides has exceeded the safety value. The Bluetooth low energy warning method proposed in this paper has the characteristics of low cost and low energy consumption. © Published under licence by IOP Publishing Ltd.

关键词： Cellular telephones

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A Modular Multi-port DC/DC Converter for DC grid

A Modular Multi-port DC/DC Converter for DC Grid

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HVDC (HVDC), International Conference on

作者： Xinying Wang Jinkun Ke Xiao Li Hangyu Xu Chunyan Ma Jiancheng Bai State Key Laboratory of Advanced Power Transmission Technology State Grid Corporation of China Beijing China Global Energy Interconnection Research Institute Co. Ltd State Grid Corporation of China Beijing China China Electric Power Research Institute State Grid Corporation of China Beijing China

ISBN: (数字)9781728175935

ISBN: (纸本)9781728175942

DC power grid provides a solution for long-distance transmission and wide-area consumption of large-scale renewable energy. The DC/DC converter is an important device in the DC power grid, which can interconnect multiple DC lines of different voltage levels. This paper proposes an easy-to-implement modular multi-port high-voltage high-power DC/DC converter. The proposed topology does not require large-capacity transformer or large inductance filter on the output DC side, and it has fault current suppression function as well as strong engineering applicability. In this paper, the control strategy of the topology and the analysis of the DC short-circuit fault characteristics are presented. The feasibility and effectiveness of the topology, control strategy and protection method are verified by simulation.

关键词： Bridge circuits Voltage control Topology Equivalent circuits power grids power transformer insulation Circuit faults

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Research on the electrical topology design of high voltage and large capacity voltage source converter

Research on the electrical topology design of high voltage a...

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The 16th IET International Conference on AC and DC power transmission (ACDC 2020)

作者： X. Wang J. Ke X. Li J. Bai H. Xu P. Chi Q. Dang Q. Li Global Energy Interconnection Research Institute Co. Ltd State Grid Beijing People’s Republic of China State Key Laboratory of Advanced Power Transmission Technology State Grid Beijing People’s Republic of China

DC grid technology based on flexible DC transmission provides new solutions to power problems such as large-scale renewable energy access, island transmission, and large city power supply. High voltage large capacity AC/DC converters and DC/DC converters have the functions of power conversion and power transfer, and are the core equipment for constructing a DC power grid. Aiming at the electrical topology of the high voltage large capacity voltage source converter, this paper proposes a topology design method based on the external voltage structure of the converter and the internal energy balance method. Firstly, the effect of the external voltage structure on the topology design is analysed. Secondly, the internal energy balance methods of the two types of converters are summarized, namely the multi-frequency method and the switching method. In this paper, a direct conversion DC/DC converter topology design is taken as an example, the application of this method is explained in detail, and the relationship between the external voltage structure of the converter and the internal energy balance is revealed.

关键词： power grids DC-DC power convertors HVDC power transmission switching convertors renewable energy sources distributed power generation AC-DC power convertors

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