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Efficient CO2 Desorption Catalysts: from Material Design to Kinetics Analysis and Application Evaluation

Engineering 2025年

作者： Xing, Lei Chen, Zhen Zhan, Guoxiong Huang, Zhoulan Wang, Lidong Li, Junhua State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment Tsinghua University Beijing100084 China MOE Key Laboratory of Resources and Environmental Systems Optimization College of Environmental Science and Engineering North China Electric Power University Beijing102206 China

Catalytic amine-solvent regeneration has been validated as an energy-saving strategy for CO2 chemisorption by boosting reaction kinetics under mild conditions. The upscale performance evaluation and long-term durability are indispensable steps for industrial application but have been scarcely reported thus far. Here, we report a ZrO2/Al2O3 pack catalyst that possesses strong metal oxide-support interactions, a porous structure, active and stable Zr–O–Al coordination, promoted proton transfer and a 40.7% decrease in the energy activation of carbamate decomposition, which significantly accelerates CO2 desorption kinetics. The upscale experiment and cost evaluation based on industrial flue gas revealed that the use of packing catalysts can reduce energy consumption by 27.56% and optimize the overall cost by 10.49%. The active sites present excellent stability in alkaline solvents. This work is the first to investigate the ability of high-technology readiness (technology readiness level at 6 (TRL 6)) for catalytic amine-solvent regeneration, providing valuable insights for potential applications involving efficient CO2 capture with catalyst assistance. © 2024 THE AUTHORS

关键词： Energy efficiency

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CCF early warning method of LCC-HVDC based on XG boost algorithm 8

CCF early warning method of LCC-HVDC based on XG boost algor...

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8th Renewable power generation Conference, RPG 2019

作者： Li, Zhizhong Wang, Bin Wang, Haigang Yu, Bin Xie, Min Chen, Shi Dong, Xinzhou Key Lab of Control and Simulation of Power Systems and Generation Equipment Department of Electrical Engineering Tsinghua University Beijing100084 China State Grid Anhui Electric Power Company Hefei 230061 China

ISBN: (纸本)9781839531255

The lack of analytical mechanism of continuous commutation failure (CCF) process hinders the development of CCF early warning algorithm and further obstructs the coordination strategy of relay protection between AC and DC size in hybrid grid. However, summarizing the protection threshold of CCF in the form of electrical quantity analytically under different fault types is a nontrivial pattern recognition problem. To overcome the difficulty of directly analysing the electromagnetic process of CCF, a statistical learning modelling approach is adapted to propose a CCF warning system, in which XGBoost algorithm was used as the backbone to regress on the relationship between AC/DC electrical quantities and the possibility of the occurrence of CCF. The design of the feature vector in XGBoost-based classifier considers not only the analytical expression of key electrical quantity during single commutation failure but also the important state variable of control system. Additionally, a special data windowing method was proposed to enrich of information encoded by the feature vector while ensuring the speed requirement posed by the protection system. Validation on multi-fault scenes simulation shows that the proposed early warning system can trigger warning signal correctly with sufficiently small measured data required, proving the practicability in engineering practice. © 2019 Institution of Engineering and Technology. All rights reserved.

关键词： HVDC power transmission

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Contaction of Atoms for Outstanding Dielectric Characteristics in Kx-Passivated Polymer Dielectrics

SSRN

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SSRN 2022年

作者： Li, Xiao-Fen Wang, Tian-Yu Liu, Bai-Xin Liu, Jian-Bo Zhang, Gui-Xin Wang, Zhong Lin School of Materials Science and Engineering Tsinghua University Beijing100084 China State Key Laboratory of Control and Simulation of Power System and Generation Equipment Department of Electrical Engineering Tsinghua University Beijing100084 China CAS Center for Excellence in Nanoscience 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 School of Material Science and Engineering Georgia Institute of Technology AtlantaGA30332 United States

High dielectric characteristics polymer dielectrics are crucial for high-power, high-integration, and high-energy storage density electrical devices and film capacitors. However, polymer dielectrics accumulate much charge during operation, causing local electric field distortion and flashover or breakdown. The deep-level defect state (electron/hole accumulation center) is a fundamental factor affecting dielectric strength. Unfortunately, related research, especially on passivating deep-level defects in polymer dielectrics, is minimal. In this paper, based on experiments and first-principles calculations, it is found that KX (X=F, Cl, Br, I) effectively passivates deep-level defect states in polymer dielectrics. Further analysis of the physical passivation mechanism reveals that the deep-level defect cation passivation principle is the cation dipole effect on polymers. The principle of anion passivation of deep-level defects by suspending anions and cations is the key to producing more stable C covalent bonds. This stable covalent bond transfers the local charge from the C with the lone electron pair that originally contains the hanging bond. Therefore, some transfer occurs and the anion implements effective passivation. This paper addresses the design of high-performance polymer dielectrics, providing a reference for experimental and theoretical analyses. © 2022, The Authors. All rights reserved.

关键词： Passivation

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High voltage gradient zinc oxide varistors for line surge arresters and GIS tank-type arresters 11

High voltage gradient zinc oxide varistors for line surge ar...

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11th Asia-Pacific International Conference on Lightning, APL 2019

作者： Meng, Pengfei Wan, Shuai He, Jinliang Zhao, Xiaolei Xu, Heng Yang, Xiao Hu, Jun State Key Laboratory of Control and Simulation of Power System and Generation Equipment Tsinghua University Beijing China Wuhan NARI Limited Liability Company State Grid Electric Power Research Institute Wuhan China

ISBN: (纸本)9781728116952

In this work, we studied multiple dopants based ZnO varistors and optimizing its microstructure and electrical properties by tailoring the sintering characteristics. The properties were evaluated by scanning electron microscopy (SEM), current-voltage characteristics, capacitance-voltage characteristics, dielectric characteristics and X-ray diffraction characteristics. At a given gallium and indium concentration, the residual voltage ratio of the sintered varistors under the 5/20μs impulse current decreased obviously as the sintering temperature increased from 1100°C to 1250°C. Besides, the nonlinear coefficient was first increased and then decreased with increasing sintering temperature. The multiple doped ZnO varistors sintered at 1250°C showed optimal performance, exhibiting a grain size of 7.1μm, residual voltage ratio of 1.56, voltage gradient of 416 V/mm, leakage current of 0.79 μA/cm2, and nonlinear coefficient of 73. When applied in power systems, the high voltage gradient varistors will make the line surge arrester in better coordination with insulators as well as reach the goal of low cost and miniaturization of GIS tank-type arresters. © 2019 IEEE.

关键词： Varistors

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Evaluating Comprehensive Development Quality of a Regional power Grid by Using an Integrated Multi-criteria Decision-Making Methodology 6

Evaluating Comprehensive Development Quality of a Regional P...

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2019 6th International Conference on Advanced Composite Materials and Manufacturing Engineering, ACMME 2019

作者： Zhang, Xiaodong Qin, Kaiming Si, Ruihua Ge, Xianjun State Grid Henan Electric Power Company Zhengzhou450018 China State Key Laboratory of Power System and Power Generation Equipment Control and Simulation Department of Electrical Engineering Tsinghua University HaidianBeijing100084 China

Due to the economic situation changes and the continuous expansion of new energy power in china, a new evaluation methodology based on multi-criteria decision making (MCDM) should be proposed to promote the comprehensive development of the new regional power grid. Some criteria were selected to constitute an indicator system from the perspectives of the safety reliability, network structure and economic benefit. Then, an integrated evaluation model was proposed based on fuzzy AHP method and VIKOR method was applied to calculate a series of comprehensive evaluation indexes. A regional power grid was chosen as an empirical analysis to demonstrate the feasibility of the evaluation system. © Published under licence by IOP Publishing Ltd.

关键词： Decision making

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Fault diagnosis for PV arrays considering dust impact based on transformed graphical features of characteristic curves and convolutional neural network with CBAM modules

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Applied Energy 2024年 355卷

作者： Jiaqi Qu Qiang Sun Zheng Qian Lu Wei Hamidreza Zareipour School of Instrumentation and Optoelectronic Engineering Beihang University Beijing China State Key Laboratory of Control and Simulation of Power System and Generation Equipment Department of Electrical Engineering Tsinghua University Beijing China School of Electronics and Information Engineering Beihang University Beijing China The Department of Electrical and Computer Engineering University of Calgary Calgary Canada

Various faults can occur during the operation of photovoltaic (PV) arrays, and both dust-affected operating conditions and various diode configurations complicate the faults. However, current methods for fault diagnosis based on I-V characteristic curves usually do not effectively use all the distinguishable information contained in the I-V curves or often rely on calibrating the field characteristic curves to standard test conditions (STC). It is difficult to apply these methods in practice and accurately identify multiple complex faults with similarities in different blocking diode configurations of PV arrays under the influence of dust. Therefore, a novel fault-diagnosis method for PV arrays that considers the impact of dust is proposed. In the pre-processing stage, the Isc-Voc normalized Gramian angular difference field (GADF) method is presented, which normalizes and transforms the resampled PV array characteristic curves from the field, including I-V and P-V, to obtain transformed graphical feature matrices. Subsequently, in the fault diagnosis stage, the convolutional neural network (CNN) model with convolutional block attention modules (CBAM) is designed to classify faults, which identifies complex fault types from the transformed graphical matrices containing complete discriminative fault information. In addition, the performances of different graphical feature transformation and CNN-based classification methods are compared using case studies. The results indicate that the developed method for PV arrays with different blocking diode configurations under various operating conditions has high fault diagnosis accuracy and reliability.

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From Distributed Energy Resources to Virtual power Plants: A Cyber-Physical System Solution for Integrating Demand-side in Smart Grid

From Distributed Energy Resources to Virtual Power Plants: A...

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IEEE Conference on Energy Internet and Energy System Integration (EI2)

作者： Liting Tian Lin Cheng Yuxiang Wan Kai Yuan Rui Liu Kuihua Wu State Key Laboratory of Control and Simulation of Power Systems and Generation Equipment Tsinghua University Beijing China State Grid Economic & Technology Research Institute Beijing China Economic & Technology Research Institute State Grid Shandong Electric Power Company Jinan China

ISBN: (数字)9781728196060

ISBN: (纸本)9781728196077

Distributed Energy Resources(DERs) will be an important part of the future power system under the spread of distributed renewable energy generation, electric vehicles, demand response and other technologies. Cyber-physical system (CPS) is one of the development directions for the future smart grid to integrate the widespread DERs. First, this paper presents the basic architecture and operation process of virtual power plant (VPP). Then the solution of communication structure and software platform are proposed. It is pointed out that virtual power plants have good applicability in information and communication infrastructure, power market and DER integration. Finally, a demonstration program in china is introduced. The research and application of virtual power plant is currently in its embryonic form. It provides a solution for the transmission from centralized power production to the distributed energy utilization, and is an adequate way to integrate geographical dispersion, heterogeneous DERs.

关键词： Renewable energy sources Transforms System integration Cyber-physical systems power markets Software Smart grids

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The parameter design method of smoothing inductance based on MMC-MTDC with R-type superconducting fault current limiter

The parameter design method of smoothing inductance based on...

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

作者： P. Guo Z. Yuan G. Liu Y. Zhao Z. Shi Tsinghua University State Key Laboratory of Control and Simulation of Power Systems and Generation Equipment Department of Electrical Engineering Beijing China Shenzhen Power Supply Corporation Shenzhen China Sichuan Energy Internet Research Institute Tsinghua University Chengdu China

The rapid increase of voltage sourced converter brings the great development of the multi-terminal DC technology, both in the DC transmission and DC distribution fields. However, because of the weak impedance characteristic of the VSC-HVDC system, how to suppress and clear DC fault currents becomes a challenge. Considering the stability, the response speed and the system structure, it is not possible to apply excessive inductance at the DC side, hence, the current limiting effectiveness is relatively restricted. On the one hand, with the effective properties, Resistive type Superconducting Fault Current Limiter (R-SFCL) becomes an effective device to solve the problem of VSC-HVDC system under DC faults. On the other hand, because of dynamic energy-impedance characteristics of R-SFCL, the fixed impedance selection method at a certain time to carry out dynamic current limiting analysis is no longer applicable. Therefore, the DC fault current research and R-SFCL characteristic are comprehensively analyzed firstly in this paper. Based on that, a smoothing inductance determination method is proposed to cut off the DC fault current by DC breaker and ensure the continuous operation of remaining parts. Finally, based on a multi-terminal DC system simulation, the improvement and effectiveness of the proposed method are validated.

关键词： power transmission faults HVDC power transmission superconducting fault current limiters HVDC power convertors voltage-source convertors

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Tertiary regulation of cascaded run-of-the-river hydropower in the islanded renewable power system considering multi-timescale dynamics

arXiv

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arXiv 2020年

作者： Qiu, Yiwei Lin, Jin Liu, Feng Dai, Ningyi Song, Yonghua Chen, Gang Ding, Lijie State Key Laboratory of Control and Simulation of Power Systems and Generation Equipment Department of Electrical Engineering Tsinghua University Beijing100087 China State Key Laboratory of Internet of Things for Smart City University of Macau 999078 China State Grid Sichuan Electric Power Research Institute Chengdu610000 China

To enable power supply in rural areas and to exploit clean energy, fully renewable power systems consisting of cascaded run-of-the-river hydropower and volatile energies such as pv and wind are built around the world. In islanded operation mode, the primary and secondary frequency control, i.e., hydro governors and automatic generation control (AGC), are responsible for the frequency stability. However, due to limited water storage capacity of run-of-the-river hydropower and river dynamics constraints, without coordination between the cascaded plants, the traditional AGC with fixed participation factors cannot fully exploit the adjustability of cascaded hydropower. When imbalances between the volatile energy and load occur, load shedding can be inevitable. To address this issue, this paper proposes a coordinated tertiary control approach by jointly considering power system dynamics and the river dynamics that couples the cascaded hydropower plants. The timescales of the power system and river dynamics are very different. To unify the multi-timescale dynamics to establish a model predictive controller that coordinates the cascaded plants, the relation between AGC parameters and turbine discharge over a time interval is approximated by a data-based second-order polynomial surrogate model. The cascaded plants are coordinated by optimising AGC participation factors in a receding-horizon manner, and load shedding is minimised. simulation of a real-life system with real-time pv data collected on site shows the proposed method significantly reduces load loss under pv volatility. Copyright © 2020, The Authors. All rights reserved.

关键词： Electric load shedding

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Investigation on Insulating Properties of Epoxy Resin Impregnated Paper Affected by Curing Agents and Accelerator Contents

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IEEE Transactions on Dielectrics and Electrical Insulation 2025年

作者： Teng, Chenyuan Ding, Yichao Zhou, Yuanxiang Zhao, Lei Zhang, Yunxiao Chen, Haoran Zhang, Youbing Zhejiang University of Technology College of Information Engineering Hangzhou310023 China Nankai University China and College of Electronic Information and Optical Engineering Tianjin300350 China Zhejiang Testing & Inspection Institute for Mechanical and Electrical Products Quality Co. Ltd Hangzhou310051 China Tsinghua University State Key Laboratory of Control and Simulation of Power Systems and Generation Equipment Department of Electrical Engineering Beijing100084 China State Grid Xinxiang Electric Power Supply Company Xinxiang453002 China

The curing formula is vital to the performance of epoxy resin impregnated paper (RIP) material. This work explored the effect of curing agents and accelerator contents on the thermal and electrical properties of RIP material. It was found that the RIP material cured with 1phr accelerator has the optimal glass transition temperature, electrical conductivity, dielectric loss and DC breakdown strength compared with RIP material cured by 0.5phr, 2phr, and 3phr accelerator. The RIP material cured with MEHHPA has better thermal and insulating properties compared with the RIP material cured with METHPA. The existence of the crepe paper amplifies the influence of accelerator and curing agent for the hydroxyl groups affect the curing process as well as the chain segment arrangement. This study provides the research support for the design of the curing formula for RIP insulation used in DC bushing. © 1994-2012 IEEE.

关键词： Dielectric losses

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