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Thermodynamically constrained retrieval algorithm to estimate subpixel fire properties

Remote Sensing of Environment 2025年 328卷

作者： Chenchong Zhang Yuan Wang Jun Wang Amber Soja Emily Gargulinski David Peterson Olga Kalashnikova Bin Zhao Yafang Cheng Fangjun Li Rajan Chakrabarty Department of Earth System Science Stanford University Stanford CA 94305 USA Department of Chemical and Biochemical Engineering University of Iowa Iowa City IA 52242 USA Center for Global and Regional Environmental Research and Iowa Technology Institute University of Iowa Iowa City IA 52242 USA NASA Langley Research Center Hampton VA 23666 USA National Institute of Aerospace Hampton VA 23666 USA Marine Meteorology Division US Naval Research Laboratory Monterey CA 93943 USA Jet Propulsion Laboratory California Institute of Technology Pasadena CA 91125-0002 USA State Key Joint Laboratory of Environmental Simulation and Pollution Control School of Environment Tsinghua University Beijing 100084 China State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex Beijing 100084 China Max Planck Institute for Chemistry Mainz 55128 Germany Geospatial Sciences Center of Excellence Department of Geography and Geospatial Sciences South Dakota State University Brookings SD 57007 USA Department of Energy Environmental and Chemical Engineering Washington University in St. Louis St. Louis MO 63130-4899 USA

Satellite-based measurements have been widely used for estimating fire-emitted pollutants based on the parameters of either burned area or fire radiative power (FRP). Fire-related remote sensing additionally requires information on active fire areas and fire temperature at a subpixel scale, as well as the combustion phases (i.e., smoldering and flaming) to infer the plume injection height and to understand the mechanics of resulting atmospheric processes like pyro-convection. The FRP is as a key indicator of fire intensity that is frequently retrieved using infrared signals. The fire properties at a subpixel level, including the effective fire temperature and fire area, can be retrieved by the bi-spectral method. However, these approaches normally neglect the heat transport phenomena and subsequently fail to characterize the fire area that could be composed of different combustion phases (e.g. smoldering, flaming, or a combination of the two). Neglecting the phenomena of heat transfer leads to mis-estimation of the actual fire area and its associated emission profile for combustion products that are a function of the combustion phase. To address this challenge, this work presents a new approach to resolve the effective temperature variation inside each fire pixel using a semi-empirical heat-transfer algorithm. This algorithm utilizes radiance observations from geostationary satellites as inputs. With the aid of fine-spatial-resolution spaceborne and airborne observations, we evaluated and validated the fire retrieval performance on western US wildfires corresponding to the 2019 season. Our results show that FRP obtained through this heat-transfer method exhibits a stronger linear correlation with those retrieved from airborne measurements. Moreover, by analyzing the temperature variation curve obtained using this method, it is possible to further retrieve the fire area under different combustion conditions within the fire pixels.

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Coordinate Dispatch of Combined Heat and power system Based on Approximate Dynamic Programming

Coordinate Dispatch of Combined Heat and Power System Based ...

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

作者： Bo Hu Ding Liu Chuanzhi Zang Yue Wang Wanting Li Yuqi Liu Peng Zeng State Grid Liaoning Electric Power Co. Ltd. Liaoning Shenyang China Key Laboratory of Networked Control System Shenyang Institute of Automation Chinese Academy of Sciences Liaoning Shenyang China Chinese Academy of Sciences University Beijing China Liaoning Lightning Protection Technical Service Center Shenyang Liaoning China

ISBN: (数字)9781728196060

ISBN: (纸本)9781728196077

Combined heat and power (CHP) can simultaneously produce electrical and thermal energy. CHP is an important and main component of the power system in areas with heat demand. However, its operating mode limits the flexibility of the system and aggravates the waste of renewable energy. This paper presents a coordinate dispatch algorithm for electric heating integrated energy system (EHIES), a combined heat and power system with wind power. An efficient optimization algorithm based on dynamic programming (DP) is developed, which overcomes the challenges of solving high dimensional optimization problems for the EHIES. The results of simulation experiments show that the proposed coordinate dispatch algorithm can meet the scheduling time requirements, reduce the operating cost of the system and realize the full consumption of wind power.

关键词： Cogeneration Heuristic algorithms Wind power generation Dynamic programming Optimization Space heating Resistance heating

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Influencing Factor and Error Analysis of Operating Capacitor Voltage Transformer Harmonic Measurement

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Journal of Physics: Conference Series 2021年第1期2121卷

作者： Yan Zhang Huajia Wang Danwen Yu Liu Yang Wenjun Cao Yongxin Yang State Grid Shandong Electric Power Research Institute Jinan 250003 China Key Laboratory of Power System Intelligent Dispatch and Control of Ministry of Education Shandong University Jinan 250061 China State Grid Energy Research Institute Co. Ltd. Beijing 100031 China

With the increasing demands of power quality monitoring and management, the problem of harmonic measurement error caused by the widespread operation of capacitor voltage transformers (CVT) in high-voltage power grids has been unavoidable. This paper analyses the influence of environmental factors on harmonic measurement error of CVT, and proposes a new method for analysing the harmonic measurement errors of operating CVT, which explains the unstable phenomenon of CVT measurement errors based on field comparison test, and provides a progressing screening method of effective analysis data. the CVT harmonic error characteristic analysis method proposed in this paper considers the impact of field installation conditions, electromagnetic environment, and other actual operating environment, which can reflect the actual harmonic error characteristics of CVT in field operation. A CVT harmonic measurement system is established based on the proposed method. The validation and effectiveness of the proposed method is illustrated on a field measurements of 1000kV CVT in Shandong Province.

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Maintenance Scheduling of power Equipment Considering Opportunistic Maintenance Strategy

Maintenance Scheduling of Power Equipment Considering Opport...

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作者： Bo Xu Yumin Zhang Kongming Sun State Grid Energy Research Institute Co. Ltd. Key Laboratory of Power System Intelligent Dispatch and Control of Ministry of Education Shandong University State Grid Shandong Electric Power Research Institute

This paper investigates the impact of opportunistic maintenance strategy on power equipment maintenance scheduling under economic *** model focuses on power equipment with two types of failures:random failure and deterioration *** previous research which didn't consider opportunistic maintenance between different failures modes,opportunistic maintenance strategy is proposed in this *** the opportunistic maintenance strategy,whenever random failure occurs,decision has to be made on whether deterioration failure is preventively maintained based on the degree of equipment deterioration and economic ***,Markov process is used to describe equipment state-space *** then,in order to determine the optimal inspection rate,preventive maintenance threshold and opportunistic maintenance threshold of power equipment,the analytical expressions of inspection cost,maintenance cost,repair cost and outage cost are ***,the total cost is minimized to get the optimal maintenance *** studies demonstrate the feasibility of the proposed model.

关键词： Maintenance Scheduling of power Equipment Considering Opportunistic Maintenance Strategy

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Fault Cause Identification Method Based on Multi-Source Information Fusion for UHVDC Transmission Lines

Fault Cause Identification Method Based on Multi-Source Info...

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International Conference on Advanced power system Automation and Protection (APAP)

作者： Rongqi Fan Jing Li Ning Ge Kuan Li Zhiyuan Wang Huanhuan Yin State Grid Shandong Electric Power Company Jinan China State Grid Shandong Electric Power Research Institute Jinan China Key Laboratory of Power System Intelligent Dispatch and Control Shandong University Ministry of Education Jinan China

ISBN: (数字)9781728117225

ISBN: (纸本)9781728117232

This paper proposes a fault cause identification method based on multi-source information for UHVDC transmission lines. The multi-source fault information used in this paper includes voltage, current,weather, season, time period, terrain and historical fault information. Firstly, the method analyzes multi-source fault information to extract fault features. Then, the BP neural network is used to fuse the multi-source fault feature. The output of the BP neural network is the probability of failure causes. This method selects the fault type with the highest probability. The effectiveness and feasibility of the method in identifying different types of fault causes are demonstrated by case tests.

关键词： Fault diagnosis Lightning Feature extraction Pollution Flashover Fires Wind

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Confidence interval based distributionally robust real-time dispatch considering wind power uncertainty

Confidence interval based distributionally robust real-time ...

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8th Renewable power Generation Conference (RPG 2019)

作者： Peng Li Ming Yang Jiajun Yang Pingjing Du Fangqing Yan Yi Zhu Key Laboratory of Power System Intelligent Dispatch and Control Shandong University Jinan 250061 China Economic & Technology Research Institute of State Grid Shandong Electric Power Company Jinan 250021 China

ISBN: (数字)9781839531248

ISBN: (纸本)9781839531255

A confidence interval based distributionally robust real-time dispatch (CI-DRTD) approach considering wind power uncertainty is proposed, which can strike a balance between the operational costs and risk even when the wind power probability distribution cannot be precisely estimated. Based on the imprecise probability theory, the confidence interval based ambiguity set of wind power uncertainty can be constructed. By the identification of the worst distribution, the original distributionally robust optimization problem can be reformulated as a robust economic dispatch problem. By using the algorithm developed in our previous work, the robust economic dispatch model can be reformulated as a mixed integer linear programming problem, for which off-the-shelf solvers are available. Case studies verify the effectiveness and efficiency of the proposed approach.

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Novel ZnO Varistors for Dramatically Improving Protective Effect of Surge Arresters

Novel ZnO Varistors for Dramatically Improving Protective Ef...

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International Conference on Lightning Protection (ICLP)

作者： Pengfei Meng Yao Zhou Jinbo Wu Jun Hu Jinliang He State Key Laboratory of Control and Simulation of Power System and Generation Equipment Tsinghua University Beijing China

The insulation level of power apparatus is based on the protection level of overvoltage in power systems. Deeply suppressing the switching overvoltage of UHV systems will reduce the manufacturing cost and technical bottlenecks of UHV power apparatus. We studied the effects of multi-elements doping on the electrical properties of ZnO varistors co-doped with Al2O3, Ga2O3, and In2O3 Scanning electron microscopy, current-voltage testing, capacitance-voltage testing, and X-ray diffraction were performed. The results showed that the residual voltage ratio of sintered varistors decreased as the indium dopant concentration was increased. The samples with 0.03 mol % indium, 0.2 mol % aluminum, and 0.42 mol % gallium showed excellent overall performance, exhibiting a nonlinear coefficient of 61.2, a leakage current of 1.63 μA /cm2, a 1-mA residual voltage of 435 V/mm, and a residual voltage ratio of 1.52. These optimized properties will be of great utility in the manufacture of metal oxide arresters. The protective effects of this kind of novel surge arresters for lightning and switching overvoltage in UHV systems are analyzed. With the low residual voltage ZnO varistors applied to surge arresters will dramatically improving the protective effect of surge arresters, to realize the target to deeply suppress the lightning and switching overvoltages, and then reduce the insulation level and manufacturing bottleneck of UHV power apparatus.

关键词： Zinc oxide II-VI semiconductor materials Arresters Varistors Indium Surges

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Modelling of gas turbine via discrete state-space neural networks

Modelling of gas turbine via discrete state-space neural net...

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Chinese Automation Congress (CAC)

作者： Jianhua Zhang Guanglei Cui Guolian Hou Zhiqiang Wu Jiiun Cao Penghao Fan 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

In this paper, one kind of multivariate system identification algorithm based discrete state-space neural network (DSSNN) is presented for modelling gas turbine systems with non-Gaussian disturbances. An improved performance index is proposed to train DSSNNs by using Survival Information Potential (SIP) of identification errors. Compared with the traditional Mean Square Error (MSE) based identification algorithm, simulation results demonstrate that the proposed system identification algorithm can obtain better model for 8OkW gas turbine.

关键词： power systems Turbines system identification Fuels Renewable energy sources Neural networks Handheld computers

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A Pilot DC Line Protection Scheme for Multi-Terminal HVDC Grid

A Pilot DC Line Protection Scheme for Multi-Terminal HVDC Gr...

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IEEE power and Energy Society General Meeting

作者： Qiang Huang Guibin Zou Bin Xu Jun Li Shuo Zhang Key Laboratory of Power System Intelligent Dispatch and Control of Ministry of Education (Shandong University) Ji'nan Shandong Province China State Grid Weihai Electric Power Company Weihai Shandong Province China

Pilot protection is indispensable in multi-terminal HVDC grid to ensure its safe operation. This paper proposes a pilot protection method based on voltage polarities of current-limiting reactors at the ends of DC lines. Analysis shows that the voltage polarities of terminal reactors at the two ends of DC lines are both positive when internal fault occurs, while they are opposite for external faults. Based on the aforementioned characteristic difference, a pilot protection criterion is built to distinguish internal fault from external fault. To avoid mal operation of the healthy pole generated by the coupling effect, the fault voltage of current-limiting reactor is integrated, and its polarity can be identified based on the integration value. At last, a four-terminal modular multilevel converter (MMC)-based HVDC grid simulation model is built in PSCAD/EMTDC, and the simulation results verified the effectiveness of the protection method.

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Scheduling of Fully Renewable Energy systems with CSP Plants and Pumped Storage

Scheduling of Fully Renewable Energy Systems with CSP Plants...

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China International Electrical and Energy Conference (CIEEC)

作者： Yang Cui Siyu Huang Huiquan Zhang Hongbo Li Key Laboratory of Modern Power Sysntem Simulation and Control & Renewable Energy Technology Ministry of Education (Northeast Electric Power University) Ji Lin China State Grid Jilin Power Co. Ltd. Training Center Ji Lin China

ISBN: (数字)9781728116754

ISBN: (纸本)9781728116761

Energy crisis and environmental pollution are becoming increasingly serious. Increasing the penetration rate of renewable energy in the power system can effectively solve this problem. Wind power and photovoltaic power generation are fluctuating power sources, and their large-scale interconnection will increase the difficulty of grid scheduling. Therefore, based on the regulation characteristics of concentrating solar power station, this paper proposes a green power dispatching strategy for power system with full renewable energy. The purpose of this strategy is to promote the consumption of renewable energy. The cost of power generation of each unit of the system and the security operation constraints of the grid are considered comprehensively. Finally, CPLEX optimization software was used to solve the model. The results verify the feasibility and validity of the proposed model.

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