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Soft-sensing of NOx content in power Station based on BP Neural Network, RBF Neural Network and PCA-RBF Neural Network

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IOP Conference Series: Materials Science and Engineering 2018年第6期392卷

作者： Peitao Hu Liu Changliang School of Control and Computer Engineering North China Electric Power University Baoding Hebei 071003 China State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University Changping District Beijing 102206 China

The timely and accurate measurement of the NOx content of the power plant denitrification system is very important for the precise regulation of the amount of ammonia and the control of the NOx emission. In this paper, we use 660MW coal-fired units as the research object. Combined with consideration of the poor accuracy and hysteresis of NOx measurement, the prediction models are established respectively by using RBF neural network, BP neural network and PCA-RBF neural network. The PCA-RBF model is based on principal component analysis (PCA) and RBF neural network. In order to improve the accuracy of the NOx soft-sensing model, this paper simplifies the sample model by optimizing the data samples, reducing the redundant information, and using dynamic neural network to achieve more accurate and faster training model. The results show that RBF neural network is superior to BP neural network in prediction accuracy and speed, while the improved and optimized PCA-RBF model has better prediction accuracy than the RBF neural network model. At the same time, this paper provides a theoretical basis for the real-time and accurate measurement of NOx content in power station, and provides some reference for improving the measurement and control of NOx in the actual production process.

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Modeling of the Steam Pressure in Separator of a Once-through Unit Based on the ANN

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IOP Conference Series: Materials Science and Engineering 2018年第6期392卷

作者： Yingqi Li Changliang Liu School of Control and Computer Engineering North China Electric Power University Baoding Hebei 071003 China State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University Changping District Beijing 102206 China

It is challenging and interesting to establish a precise steam pressure in separator dynamic model of a once-through power plant unit in order to meet large scale load demands from the power grid and the needs of the engineering research. Steam pressure reveals the energy balance of boiler and turbine. This study proposes to establish such a steam pressure in separator mathematical model of a once-through boiler-turbine unit under dry operating conditions. Then the BP neural network model and the RBF neural network model were used to predict the steam pressure in separator, combined with running data. Moreover, in order to improve the performance of the network, the exhaustive method is used to optimize the parameters of the RBF network. After this, to further enhance model performance, the dynamic mathematical model was extended to be the one with different sets of parameters under different load ranges. More importantly, the dynamic model captures the essential dynamic characteristics of the unit. Therefore, the model can be feasible and applicable for simulation analysis and testing control algorithms.

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Chemical characteristics of fine particulate matter emitted from commercial cooking

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Frontiers of Environmental Science & Engineering 2016年第3期10卷 559-568页

作者： Bing PEI Hongyang CUI Huan LIU Naiqiang YAN School of Environmental Science and Engineering Shanghai Jiao Tong University Shanghai 200040 China Shanghai Environmental Monitoring Center Shanghai 200030 China Ministry of Education Key Laboratory for Earth System Modeling Center for Earth System Science Tsinghua University Beijing 100084 China School of Environment State Key Joint Laboratory of Environment Simulation and Pollution Control (SKLESPC) Tsinghua University Beijing 100084 China

The chemical characteristics of fine particulate matter （PM2.5） emitted from commercial cooking were explored in this study. Three typical commercial restau- rants in Shanghai, i.e., a Shanghai-style one （SHS）, a Sichuan-style one （SCS） and an Italian-style one （ITS）, were selected to conduct PM2.5 sampling. Particulate organic matter （POM） was found to be the predominant contributor to cooking-related PM2.5 mass in all the tested restaurants, with a proportion of 69.1% to 77.1%. Specifically, 80 trace organic compounds were identified and quantified by gas chromatography/mass spectrometry （GC/MS）, which accounted for 3.8%-6.5% of the total PM2.5 mass. Among the quantified organic compounds, unsaturated fatty acids had the highest concentration, followed by saturated fatty acids. Comparatively, the impacts of other kinds of organic compounds were much smaller. Oleic acid was the most abundant single species in both SCS and ITS. However, in the case of SHS, linoleic acid was the richest one. ITS produced a much larger mass fraction of most organic species in POM than the two Chinese cooking styles except for monosaccharide anhy-drides and sterols. The results of this study could be utilized to explore the contribution of cooking emissions to PM2.5 pollution and to develop the emission inventory of PM2.5 from cooking, which could then help the policymakers design efficient treatment measures and control strategies on cooking emissions in the future.

关键词： commercial cooking PM2.5 chemical char- acteristics organic matter

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Fault Diagnosis of Wind Turbine Gearbox Based on Wavelet Transform

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IOP Conference Series: Materials Science and Engineering 2018年第6期392卷

作者： Hao Li Changliang Liu School of Control and Computer Engineering North China Electric Power University Baoding Hebei 071003 China State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University Changping District Beijing 102206 China

As a kind of clean and renewable energy, wind energy is attracting more and more attention from all over the world. But the development of wind power is always hindered by the failure of downtime. The gearbox of wind power unit is one of the components with the highest failure rate in the whole wind turbine. Therefore, it is of great significance to study the fault diagnosis of gearbox in wind turbine. This paper first introduces the mathematical principle of wavelet analysis, and takes Matlab as an experimental platform to analyze and deal with the pitting fault data of a fan gearbox, and identifies the fault frequency by wavelet packet energy method, and diagnoses the type of failure. Finally, the experimental results are compared with other methods to deal with the data. Through the research in this paper, we can see that the data processing method based on wavelet analysis is simple and practical, especially in the engineering field represented by gearbox fault diagnosis.

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Internet Information Applied in the Energy Internet Planning: A Review and Outlook

Internet Information Applied in the Energy Internet Planning...

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IEEE Conference on Energy Internet and Energy system Integration

作者： Lin Cheng Xinchi Ji Fang Zhang Caihao Liang Hailei He State Key Laboratory of Control and Simulation of Power Systems and Generation Equipment Tsinghua University China Electric Power Research Institute

ISBN: (纸本)9781538614280

With the development of energy industry and infor-mation technologies, the concept of energy Internet is proposed to prevent the energy crisis and reduce the environmental pollution. However, the planning of energy Internet is facing great challenges that there are large uncertainties of boundary conditions in the planning. The collection of Internet information can help solve the problem. This paper introduces the method of collecting objective data from the Internet, such as renewable energy sources data, climate data, and economic data, and the usage of the data for energy Internet planning. The method of collecting and processing fuzzy information from the Internet are introduced as well. The events related to the energy Internet planning can be perceived and be applied to the multi-scenario planning of energy Internet. Besides, the difficulties and outlooks of the usages are given.

关键词： Energy Internet Internet information Multi-scenario Planning

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Repeated Strike Process During Disconnector Operation in Ultra-High Voltage Gas-Insulated Switchgear

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Plasma Science and Technology 2016年第3期18卷 247-253页

作者：关永刚蔡元纪陈维江刘卫东李志兵岳功昌张俊民 State Key Lab of Control and Simulation of Power System and Generation Equipments Department of Electrical EngineeringTsinghua UniversityBeijing 100084China State Grid Corporation of China Beijing 100031China China Electric Power Research Institute Beijing 100192China School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China

Very fast transient over-voltage （VFTO）, induced by disconnector operations in gas- insulated switchgears, has become the limiting dielectric stress at ultra-high voltage levels. Much work has been done to investigate single-strike waveforms of VFTO. However, little study has been carried out investigating the repeated strike process, which would influence VFTO significantly. In this paper, we carried out 450 effective experiments in an ultra-high voltage test circuit, and conducted calculations through the Monte Carlo simulation method, to investigate the repeated strike process. Firstly, the mechanism of the repeated strike process is proposed, based on the ex- perimentai results. Afterwards, statistical breakdown characteristics of disconnectors are obtained and analyzed. Finally, simulations of the repeated strike process are conducted, which indicate that the dielectric strength recovery speed and polarity effect factor have a joint effect on VFTO. This study enhances the understanding of the nature of VFTO, and may help to optimize the disconnector designed to minimize VFTO.

关键词： disconnector （DS） repeated strike process discharge statistical breakdowncharacteristics ultra-high voltage （UHV） very fast transient over-voltage （VFTO）

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Situation Awareness of Active Distribution Network:Roadmap,Technologies,and Bottlenecks

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CSEE Journal of power and Energy systems 2016年第3期2卷 35-42页

作者： Jin Lin Can Wan Yonghua Song Renle Huang Xiaoshuang Chen Wanfang Guo Yi Zong You Shi State Key Laboratory of Control and Simulation of Power Systems and Generation Equipment Department of Electrical EngineeringTsinghua UniversityBeijing 100084China State Grid Beijing Electric Power Company Beijing 102200China Center for Electric Power and Energy Technical University of DenmarkElektrovej 325DK 2800Denmark

With the rapid development of local generation and demand response,the active distribution network(ADN),which aggregates and manages miscellaneous distributed resources,has moved from theory to *** and optimal operations now require an advanced situation awareness(SA)system so that operators are aware of operation states and potential *** solutions in distribution supervisory control and data acquisition(DSCADA)as well as the distribution automation system(DAS)generally are not able to meet the technology requirements of *** this paper,the authors’participation in the project of developing an SA system as the basic component of a practical active distribution management system(ADMS)deployed in Beijing,China,is *** paper reviews the ADN’s development roadmap by illustrating the changes that are made in elements,topology,structure,and control *** into consideration these hardware changes,a systematic framework is proposed for the main components and the functional hierarchy of an SA system for the *** SA system’s implementation bottlenecks are also presented,including,but not limited to issues in big data platform,distribution forecasting,and security *** technology solutions are also provided.

关键词： Active distribution network distribution automation system roadmap situation awareness technology bottleneck

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强厄尔尼诺期间大气环流对华北地区灰霾的影响

强厄尔尼诺期间大气环流对华北地区灰霾的影响

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第24届中国大气环境科学与技术大会暨中国环境科学学会大气环境分会2018年学术年会

作者： Ge Zhang Yang Gao Wenju Cai L.Ruby Leung Shuxiao Wang Bin Zhao Minghuai Wang Huayao Shan Xiaohong Yao Huiwang Gao Key Laboratory of Marine Environmental Science and Ecology Ministry of EducationOcean University of Key Laboratory of Marine Environmental Science and Ecology Ministry of EducationOcean University of Physical Oceanography Laboratory/CIMST Ocean University of China and Qingdao National Laboratory for Atmospheric Sciences and Global Change Division Pacific Northwest National LaboratoryRichlandWashi State Key Joint Laboratory of Environment Simulation and Pollution Control School of EnvironmentTsi Joint Institute for Regional Earth System Science and Engineering and Department of Atmospheric and School of Atmospheric Sciences Nanjing UniversityNanjing210023China

利用全国PM2.5监测网数据分析发现，华北地区在 2015 年 12 月和 2016 年 1 月出现 PM2.5 浓度异常高、低的跷跷板现象，此现象可能与强厄尔尼诺和北极涛动(AO)共同导致的局地气象变化有关.

关键词：灰霾强厄尔尼诺北极涛动东亚冬季风 WRF-CMAQ

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Stabilization and assessment of interaction dynamics for More Electric Aircraft

Stabilization and assessment of interaction dynamics for Mor...

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International Conference on power Electronics and Motion control (IPEMC)

作者： Xuan Zhang Lie Xu Yongdong Li Zedong Zheng Kui Wang State Key Laboratory of Control and Simulation of Power System and Generation Equipment Tsinghua University Beijing China

ISBN: (纸本)9781509012114

This paper proposes a novel active stabilization method based on reshaping the output impedance of the source-side PWM rectifier for More Electric Aircraft (MEA) power system. A nonlinear compensation signal is injected into AC voltage command of PWM rectifier to adding a virtual resistor paralleled with DC bus capacitor. Thus, the instability caused by constant power loads (CPLs) can be neutralized. Compared to conventional active damping methods, the value of compensation signal can be expressed by the virtual resistor so that the physical mechanism of stability improvement can be clarified. Besides, all remote sensors providing load input voltages can be removed. Stability and sensitivity of the proposed active stabilization method are analyzed qualitatively. The interaction dynamics of passive devices, such as LC filters of CPLs and DC capacitors on source side are discussed. simulation results validate the effectiveness of the proposed method.

关键词： Damping Pulse width modulation Rectifiers power system stability Capacitors Stability analysis Mathematical model

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Unit Commitment Considering Demand Response Behavior Based on Utility Maximization

Unit Commitment Considering Demand Response Behavior Based o...

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IEEE Conference on Energy Internet and Energy system Integration

作者： Yumin Zhang Xueshan Han Bo Xu Li Zhang Donglei Sun Xiaofeng Miao Jiayin Jiang Key Laboratory of Power System Intelligent Dispatch and Control of Ministry of Education Shandong University State Key Laboratory of Control and Simulation of Power Systems and Generation Equipment (Department of Electrical Engineering Tsinghua University) Economic & Technology Research Institute of State Grid Shandong Electric Power Company State Grid Shandong Electric Power Company Yantai Electric Power Company

ISBN: (纸本)9781538614280

The active participation of demand side resources in power grid operation not only benefits the individual participant but also benefits the whole system. The optimal goal can promote by excavating the active behaviors of demand side. The welfare maximization of market participant is the driving force of such active behaviors. Considering the independence of each user's behavior, the consumer's utility function is selected to depict consumer's preference and demand response behavior. In order to coordinate the consumers' maximum welfare with social welfare maximization, consumers' utility function and units' operation cost are integrated into Unit Commitment (UC) model. The objective function is to maximize social welfare, by subtracting units' operation cost from consumers' total utility, and this objective can be acquired. Considering the proposed model should be solved in a distributed manner, the idea of the centralized coordination and the decentralized decision-making is proposed. Based on the Lagrangian relaxation (LR) principle and distributed real-time pricing scheme, a closed-loop feedback mechanism is constructed to reflect the relationship among generator output, price level, and load demand. The ten generating units example can illustrate the effectiveness of the proposed method.

关键词： Demand utility Decomposition coordination Electricity market Lagrangian relaxation Real-time pricing Unit commitment

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