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design and Application research of Synchronous Temporary Block Function between Valve Groups on Modular Multilevel Converter Ultra High Voltage direct Current system

Design and Application Research of Synchronous Temporary Blo...

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Sustainable Power and Energy Conference (iSPEC)

作者： Qinlei Chen Xuehua Lin Zhijiang Liu Qi Guo Libin Huang Guanming Zeng Shuyong Li deyang Chen Chao Luo Electric Power Research Institute China Southern Power Grid Guangzhou China CSG Key Laboratory for Power System Simulation China Southern Power Grid Guangzhou China State Key Laboratory of HVDC China Southern Power Grid Guangzhou China Guangdong Provincial Key Laboratory of Intelligent Operation and Control for New Energy Power System China Southern Power Grid Guangzhou China National Energy Power Grid Technology R&D Centre China Southern Power Grid Guangzhou China

ISBN: (纸本)9781665485234

Compared with the half controlled power electronic devices such as thyristor, the over-current ability of fully controlled power electronic devices such as insulated gate bipolar transistor (IGBT) is weak. In order to ensure that bridge arm current does not exceed the bearing range of modular multilevel converter (MMC) switching devices under AC fault ride through and other scenarios, MMC high voltage direct current (HVdC) system projects are equipped with temporary block (TB) function, IGBTs are protected by suspending the trigger pulse before bridge arm current reaches the maximum safe current of the switch. The structure of high side and low side valve group (VG) in series are adopted in ultra high voltage direct current (UHVdC) system. For line commuted converter (LCC) UHVdC system, the converter is current source type, during normal operation, there is no need to control the voltage balance between high side and low side VG, and after one VG is disturbed by commutation failure, the impact on another VG is relatively small. For MMC-UHVdC system, the converter is voltage source type, during normal operation, the voltage balance between high side and low side VG should be controlled. When a transient disturbance such as AC fault occurs, if one VG is temporary blocked due to bridge arm over-current, and another VG is not temporary blocked or the time of temporary blocked is later, the VG blocked first may tripped due to sub-module (SM) overall over-voltage or bridge arm over-current, and the scope of the accident is expanded, which is not conducive to the flexible and reliable operation of MMC-UHVdC. Therefore, the impact of non synchronous temporary block of MMC-UHVdC VGs is firstly analyzed in this paper, and then synchronous temporary block (STB) function between VGs is proposed, and the hardware interface scheme, STB signal sending and receiving logic, enable conditions and other aspects between VGs are elaborated. Finally, taking kunliulong project, the world’

关键词： Insulated gate bipolar transistors Multilevel converters Bridge circuits High-voltage techniques Switches Valves real-time systems

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A new optical concept for high duty vertical alignment liquid crystal displays

A new optical concept for high duty vertical alignment liqui...

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International Conference on display Technology, ICdT 2019

作者： Wu, Zirong Chen, Congxin Zhao, Zuzheng Optoelectronics and Intelligent Control R&D Center of Tsinghua University in Shenzhen and Shenzhen AV-display Co. Ltd. Shenzhen China

ISBN: (纸本)9781510896161

Passive matrix driven vertical alignment liquid crystal displays (PMVA-LCd) become more and more popular in many applications like industry, automotive, e-metering, medical, sports, smart home etc. regarding its high contrast and wide view angle. However, the current solution of vertical alignment liquid crystal display has a shortcoming on the steepness of the transmissive-voltage curve (T-V curve) of the displays, which limits the driving duty of displays. We developped a new optical concept to achieve high duty, up to 1/128, PMVA-LCd displays by optical-electro simulations and experiments. © 2019, John Wiley and Sons Inc. All rights reserved.

关键词： Liquid crystal displays

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Plastic Shavings by Laser: Peeling Porous Graphene Springs for Multifunctional All-Carbon Applications

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Advanced Science 2023年第21期10卷 e2301208页

作者： Kim, Chanwoo Hwang, Eunseung Kwon, Jinhyeong Jang, Tae Hwan Lee, Won Chul Kim, Shi Hyeong Park, Jongmin Lee, Ming-Tsang Kim, Hyun Hong, Sukjoon Lee, Habeom School of Mechanical Engineering Pusan National University Busan46241 Korea Republic of Optical Nanoprocessing Lab Department of Mechanical Engineering BK21 FOUR ERICA ACE Center Hanyang University Gyeonggi-do Ansan15588 Korea Republic of Intelligent Manufacturing System R&D Department Korea Institute of Industrial Technology Chungcheongnam-do Cheonan31056 Korea Republic of Division of Electrical Engineering Hanyang University ERICA Gyeonggi-do Ansan15588 Korea Republic of Department of Mechanical Engineering BK21 FOUR ERICA ACE Center Hanyang University Gyeonggi-do Ansan15588 Korea Republic of Department of Advanced Textile R&D Korea Institute of Industrial Technology Gyeonggi-do Ansan15588 Korea Republic of HYU-KITECH Joint Department Hanyang University Seoul04763 Korea Republic of Advanced Materials Division Korea Research Institute of Chemical Technology Daejeon34114 Korea Republic of Department of Power Mechanical Engineering National Tsing Hua University Hsinchu30013 Taiwan

Manufacturing strategies to create three-dimensional (3d) structures with multifunctional nanomaterials are of intense interest for fabricating building blocks in many electromechanical applications. A coil spring composed of graphene provides an important step toward the realization of all-carbon devices, as it is one of the essential elements for a wide range of systems. In this connection, here an unprecedented fabrication strategy to create a new type of 3d coil spring composed of laser-induced graphene springs (LIG-S) which is spontaneously produced via the pyrolytic jetting technique, is presented. Similar to wood or metal shavings observed in traditional machining processes, a pair of LIG-S with two opposite chiralities and controllable macroscopic dimensions is produced by a single scanning of a focused continuous-wave (CW) laser on a polyimide (PI) substrate. The resulting LIG-S, plastic shavings by laser, exhibits sufficient mechanical and electrical properties to enable many applications including strain-tolerant spring electrodes, antennas, supercapacitors, gas sensors, and luminescent filaments under extreme conditions. Without using any conventional fabrication techniques or other labor-intensive, time-consuming, and expensive processes, this novel approach enables a high-throughput mass production of macro-, micro-, and nanoscale featured LIG-S that can be manufactured within seconds to realize many open opportunities in all-carbon electromechanical systems. © 2023 The Authors. Advanced Science published by Wiley-VCH GmbH.

关键词： Fabrication

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Advanced Out-of-Step Splitting Protection Simulation Platform with Considering High Frequency Generation Tripping and Low Frequency Load Shedding

Advanced Out-of-Step Splitting Protection Simulation Platfor...

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Power systems and Electrical Technology (PSET), IEEE International Conference on

作者： ren Liu Yukun Zhu Yihua Zhu dongxu Chang Mingkang Wu Libin Huang State Key Laboratory of HVDC Electric Power Research Institute China Southern Power Grid Guangzhou China National Energy Power Grid Technology R&D Centre Electric Power Research Institute China Southern Power Grid Guangzhou China Guangdong Provincial Key Laboratory of Intelligent Operation and Control for New Energy Power System Electric Power Research Institute China Southern Power Grid Guangzhou China CSG Key Laboratory for Power System Simulation Electric Power Research Institute China Southern Power Grid Guangzhou China

This paper presents an advanced out-of-step (OOS) splitting protection simulation platform considering high frequency generation tripping and low frequency load shedding. In the proposed simulation platform, real-Time digital Simulator (rTdS) is utilized as the real-time power system simulator. Through the high-speed I/O card, real industry OOS splitting protection device is integrated into the proposed simulation platform. Based on the real China South Power Grid (CSG) control strategy, high frequency generation tripping and low frequency load shedding components are modelled in the simulation. CSG real grid is modelled in the rTdS to perform the real-time hardware-in-the-loop simulation. Simulation results present that there is a clear difference between with high frequency generation tripping results and without high frequency generation tripping results.

关键词： Performance evaluation Industries Hardware-in-the-loop simulation Load shedding real-time systems Power grids High frequency

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Influence Analysis of Thermal States on dynamic Frequency response for Power systems with High renewables

Influence Analysis of Thermal States on Dynamic Frequency Re...

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Sustainable Power and Energy Conference (iSPEC)

作者： Yongji Cao Hengxu Zhang Changgang Li Leshu Sun Chen Li Hao Qin Qi Guo Yihua Zhu Key Laboratory of Power System Intelligent Dispatch and Control of the Ministry of Education Shandong University Jinan China State Key Laboratory of HVDC Electric Power Research Institute National Energy Power Grid Technology R&D Centre Guangdong Provincial Key Laboratory of Intelligent Operation and Control for New Energy Power System Guangzhou China

ISBN: (数字)9781728191645

ISBN: (纸本)9781728191652

As thermal generators are substituted by renewables, the power reserves are decreasing and the influence of boiler thermal states on frequency dynamics becomes more severe. The variations of thermal states can aggravate dynamic frequency response, especially for power systems with high renewables. However, the system frequency response (SFr) model has been widely adopted, but in which the thermal states are neglected. This paper analyzes the influence of thermal states on dynamic frequency response quantitatively. The modified SFr models are built by extending the boiler models with different simplification degrees. Then, from the view of the response amplitude and time, the quantitative indices are established to measure the response trajectories of modified SFr models. And the characteristics of frequency dynamics and the statistic indices of data sequences are utilized to analyze the influences of thermal states and assess the performances of modified SFr models. According to the results of comparative analysis, the neglect of thermal states incurs more optimistic frequency dynamics and impairs the frequency stability of power systems with high renewables. Additionally, the accuracy of the SFr model can be enhanced even with the most simplified boiler model.

关键词： Analytical models Power system dynamics Power system stability Boilers Frequency response Thermal analysis Thermal stability

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The characteristics of sintered copper layer by pressure sintering process for power module application

The characteristics of sintered copper layer by pressure sin...

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International Exhibition and Conference for Power Electronics, intelligent Motion, renewable Energy and Energy Management, PCIM Europe 2019

作者： Yamauchi, Shinichi Anai, K. Jo, J.L. Sakaue, T. Chang, J.Y. Fun, S.Y. Cheng, K.H. Cheng, H.W. Lin, H.H. Han, W.K. Hsu, S.F. Tseng, C.M. Chang, T.C. Engineered Materials Sector R&D Center Mitsui Mining & Smelting Co. Ltd Japan Intelligent Power Module & System Department Electronics and Optoelectronics system Research Laboratories Industrial Technology Research Institute Taiwan

ISBN: (纸本)9783800749386

Copper sinter materials were investigated for potential use as joining material. In this study we evaluated newly developed Cu sinter paste for joining material and studied initial joining properties and reliability with power module. The shear strength of Cu joining exceeded 70 MPa without voids in initial junction by optimizing joining conditions. Furthermore, the reliability with power module was also evaluated, which indicated no significant change of thermal resistance after TCT. © VdE VErLAG GMBH · Berlin · Offenbach.

关键词： Sintering

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Optimizing Photocatalytic Performance in an Electrostatic-Photocatalytic Air Purification system Through Integration of Triboelectric Nanogenerator and Tesla Valve

SSRN

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SSrN 2024年

作者： Li, Xiaoliang Cao, Leo N.Y. Zhang, Ting Fang, rongkun ren, Yuqing Chen, Xiangyu Bian, Zhenfeng Li, Hexing MOE Key Laboratory of Resource Chemistry Shanghai Key Laboratory of Rare Earth Functional Materials Shanghai Normal University Shanghai China CAS Center for Excellence in Nanoscience Beijing Key Laboratory of Micro-nano Energy and Sensor Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of Sciences Beijing100083 China School of Nanoscience and Technology University of Chinese Academy of Sciences Beijing100049 China Sino-Dutch R&D Centre for Future Wastewater Treatment Technologies Key Laboratory of Urban Stormwater System and Water Environment Beijing University of Civil Engineering and Architecture Beijing100044 China State Key Laboratory of Pollution Control and Resource Reuse College of Environmental Science and Engineering Tongji University Shanghai200092 China Shanghai University of Electric Power Shanghai China

Increasing the collision frequency between gas molecules and photocatalysts can enhance the removal efficiency of volatile organic compounds (VOCs) and particulate matter (PM) in air. In this study, we propose an Electrostatic-Photocatalytic air purification system, containing Tesla valve, triboelectric nanogenerator (TENG), and photocatalysis parts. The incorporation of Ag@ZnO nanorod array (Ag@ZnO-Nr) photocatalysts into the internal baffles of the Tesla valve pipeline effectively enhances the collision probability between air pollutant molecules and photocatalysts, and thus facilitating the removal efficiency of pollutants. Additionally, the high-voltage electricity (~9.0 kV) generated by the TENG facilitates the separation of electron-hole pairs in the photocatalyst, leading to increased production of superoxide radicals (O·-2), hydroxyl radicals (·OH), and holes (h+), thereby enhancing the photocatalytic efficiency. In a 1.8 L space system, we achieved an approximately 97% removal efficiency for toluene within 130 minutes and a similar efficiency for formaldehyde (~200 ppm) within 175 minutes. Additionally, the PM2.5 concentration rapidly decreased from 999 μg·m-3 to 42 μg·m-3 within 6 minutes, alongside with a significantly faster pollutant removal rate compared to conventional methods. By integrating Tesla valves, TENG, and photocatalysis, this combined system presents an efficient and promising approach for addressing indoor air pollution, with potential applications across various settings. © 2024, The Authors. All rights reserved.

关键词： Photocatalysis

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Coordinated Frequency control of Generation and demand Side Considering demand Side resource Callback Characteristic

Coordinated Frequency Control of Generation and Demand Side ...

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IEEE International Conference on Automation, Electronics and Electrical Engineering (AUTEEE)

作者： Zhenxing Li Xin Shan Zhixian Wang Kun Yuan Ying Wang Kaifeng Zhang Key Laboratory of Measurement and Control of CSE Southeast University Nanjing China System R&D Center NARI Group Corporation (State Grid Electric Power Research Institute) Nanjing China

The following topics are dealt with: learning (artificial intelligence); power engineering computing; feature extraction; power generation control; power grids; convolutional neural nets; natural language processing; ... 详细信息

ISBN: (数字)9781728198279

ISBN: (纸本)9781728181585

关键词： Frequency control Temperature Load modeling Time-frequency analysis regulation Load shedding Temperature distribution

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Method of Electronic Component Location, Grasping and Inserting Based on Machine Vision

Method of Electronic Component Location, Grasping and Insert...

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International Wireless Communications and Mobile Computing Conference, IWCMC

作者： Bin Xue Chang Sun Huihui Chu Qingsen Meng Shuanben Jiao Engineering and Technology R&D center of Mechanical and Electrical in Colleges of Shandong Qingdao Binhai University Shandong PR China Qingdao Zhongzhuang Vision Automation System Control Co. Ltd Shandong PR China

ISBN: (数字)9781728131290

ISBN: (纸本)9781728131306

Aiming at the problems of low efficiency, high cost, missing or wrong insertion of labor in PCB production, a method of electronic component location, grabbing and inserting based on machine vision is proposed. By building the machine vision system, three industrial cameras cooperate with dome light sources to take images of the whole components, the pin features of components and the jack features of PCB board respectively. After image acquisition, image processing is carried out on VisionPro 9.0 software platform, which mainly completes feature extraction of component pins and PCB board jacks, and coordinates positioning. Then, coordinate transformation is carried out by nine-point calibration method to guide the manipulator to complete the work of location, grabbing and inserting. Through the running test, the system has a fast grabbing speed and inserting speed. The error inserting rate, missing inserting rate, bad product rate and inserting precision all reach the standard, and the working efficiency is three times that of the manual.

关键词： Pins Feature extraction Machine vision Lifting equipment Manipulators Cameras Image color analysis

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Variational Autoencoder Based Fault detection and Location Method for Power distribution Network

Variational Autoencoder Based Fault Detection and Location M...

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International Conference on Condition Monitoring and diagnosis, CMd

作者： Xuhong Wang Ping Cui Ying du Yupu Yang The Ministry of Education Key Laboratory of System control and information processing Shanghai Jiao Tong University Shanghai China State Energy Smart Grid R&D Center Shanghai Jiao Tong University Shanghai China

ISBN: (数字)9781728159317

ISBN: (纸本)9781728159324

With the rapid development of the world economy and the continuous improvement of people's living standards, users put forward higher requirements for the quality and reliability of the power system. As a representative of deep learning, variational autoencoders play an important role in processing high-dimensional big data. In this paper, a novel variational autoencoder based distribution network abnormal monitoring and positioning method is proposed. Through an indepth study of the variational autoencoder, we utilize the real-time dynamic distribution network status information provided by the wide-area measurement system, combined with the abilities of feature extracting and data reconstruction. Finally, the IEEE-33 simulation model was built in Matlab software and the experimental results were used to verify the correctness of this method. The results show that this method can quickly and accurately achieve the fault detection and location for the distribution network with strong robustness.

关键词： Fault detection distribution networks Feature extraction Electrical fault detection Software Wide area measurements Standards

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