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The present study proposes a hierarchical wide-area decentralized coordinated control framework for HVDC power system that is robust to multiple operating conditions. The upper level wide-area coordinated controller is designed in the form of dynamic output feedback control that coordinates the lower level HVDC supplementary controller, PSS, and SVC. In order to enhance the robustness of the designed controller under various operating conditions, the polytopic model is introduced such that the closed-loop control system can be operated under strong damping mode in virtue of the stability criterion based on damping ratio. Simulation results demonstrate that the proposed controller design algorithm is capable of enhancing the system damping over four different conditions.
Shiyun Xu; Huadong Sun; Baiqing Li; Guangquan Bu; Jun Yi; Jian Zhang; Bing Zhao; Zhanming Chen. Wide-Area Robust Decentralized Coordinated Control of HVDC Power System Based on Polytopic System Theory. Mathematical Problems in Engineering 2015, 2015, 1 -9.
AMA StyleShiyun Xu, Huadong Sun, Baiqing Li, Guangquan Bu, Jun Yi, Jian Zhang, Bing Zhao, Zhanming Chen. Wide-Area Robust Decentralized Coordinated Control of HVDC Power System Based on Polytopic System Theory. Mathematical Problems in Engineering. 2015; 2015 ():1-9.
Chicago/Turabian StyleShiyun Xu; Huadong Sun; Baiqing Li; Guangquan Bu; Jun Yi; Jian Zhang; Bing Zhao; Zhanming Chen. 2015. "Wide-Area Robust Decentralized Coordinated Control of HVDC Power System Based on Polytopic System Theory." Mathematical Problems in Engineering 2015, no. : 1-9.
In contrast to the ever-increasing focus on China's CO2 emissions, little attention has been given to its non-CO2 greenhouse gases (GHGs). Based on the latest released official GHG emission data, this paper presents an inventory and embodiment analysis of the non-CO2 GHG emissions covering CH4, N2O, HFCs, PFCs and SF6 by the Chinese economy in 2005. The total direct non-CO2 GHG emissions from economic sectors amount to 1368.5 Mt CO2-eq, of which CH4 contributes 848.4 Mt, N2O 356.8 Mt and F-GHGs 163.3 Mt. Responsible for 93.2% of the total emissions are the three sectors of Agriculture, Coal Mining and Dressing and Chemicals. Exports, urban consumption and capital formation derive the major fractions of embodied emissions for final demand. Rural and urban consumption are both non-CO2 GHG emission intensive, having the largest embodied emission intensities among all final demand categories. The impact of international trade on China's non-CO2 GHG emissions is significant. The total emissions embodied in exports are 487.0 Mt CO2-eq, equivalent to 35.6% of the total domestic emissions. Prominently, the re-exported emissions amount to 135.3 Mt CO2-eq due to the processing trade. Textile and Garments and Other Fiber Products, Leather, Furs, Down and Related Products are the top two net embodied emission export sectors. While China's non-CO2 GHG emissions are expected to increase steadily in the future, both the direct emissions from on site production and the embodied emissions induced by final consumption and international trade need to be addressed and targeted to inform effective mitigation policies.
Bo Zhang; Z.M. Chen; H. Qiao; B. Chen; T. Hayat; A. Alsaedi. China's non-CO2 greenhouse gas emissions: Inventory and input–output analysis. Ecological Informatics 2014, 26, 101 -110.
AMA StyleBo Zhang, Z.M. Chen, H. Qiao, B. Chen, T. Hayat, A. Alsaedi. China's non-CO2 greenhouse gas emissions: Inventory and input–output analysis. Ecological Informatics. 2014; 26 ():101-110.
Chicago/Turabian StyleBo Zhang; Z.M. Chen; H. Qiao; B. Chen; T. Hayat; A. Alsaedi. 2014. "China's non-CO2 greenhouse gas emissions: Inventory and input–output analysis." Ecological Informatics 26, no. : 101-110.
A new closed-loop control method based on the fuzzy adaptive unscented Kalman filter (FAUKF) is proposed to suppress epileptiform spikes in a class of neural mass models with uncertain measurement noise. The FAUKF is used to estimate the nonlinear system states of the underlying models and amend measurement noise adaptively. The control law is constructed via the estimated states. Numerical simulations illustrate the efficiency of the proposed method.
Xian Liu; Hui-Jun Liu; Ying-Gan Tang; Qing Gao; Zhan-Ming Chen. Fuzzy adaptive unscented Kalman filter control of epileptiform spikes in a class of neural mass models. Nonlinear Dynamics 2014, 76, 1291 -1299.
AMA StyleXian Liu, Hui-Jun Liu, Ying-Gan Tang, Qing Gao, Zhan-Ming Chen. Fuzzy adaptive unscented Kalman filter control of epileptiform spikes in a class of neural mass models. Nonlinear Dynamics. 2014; 76 (2):1291-1299.
Chicago/Turabian StyleXian Liu; Hui-Jun Liu; Ying-Gan Tang; Qing Gao; Zhan-Ming Chen. 2014. "Fuzzy adaptive unscented Kalman filter control of epileptiform spikes in a class of neural mass models." Nonlinear Dynamics 76, no. 2: 1291-1299.
This study presents a network simulation of the global embodied energy flows in 2007 based on a multi-region input–output model. The world economy is portrayed as a 6384-node network and the energy interactions between any two nodes are calculated and analyzed. According to the results, about 70% of the world’s direct energy input is invested in resource, heavy manufacture, and transportation sectors which provide only 30% of the embodied energy to satisfy final demand. By contrast, non-transportation services sectors contribute to 24% of the world’s demand-driven energy requirement with only 6% of the direct energy input. Commodity trade is shown to be an important alternative to fuel trade in redistributing energy, as international commodity flows embody 1.74E + 20 J of energy in magnitude up to 89% of the traded fuels. China is the largest embodied energy exporter with a net export of 3.26E + 19 J, in contrast to the United States as the largest importer with a net import of 2.50E + 19 J. The recent economic fluctuations following the financial crisis accelerate the relative expansions of energy requirement by developing countries, as a consequence China will take over the place of the United States as the world’s top demand-driven energy consumer in 2022 and India will become the third largest in 2015.
Zhan-Ming Chen; G.Q. Chen. Demand-driven energy requirement of world economy 2007: A multi-region input–output network simulation. Communications in Nonlinear Science and Numerical Simulation 2013, 18, 1757 -1774.
AMA StyleZhan-Ming Chen, G.Q. Chen. Demand-driven energy requirement of world economy 2007: A multi-region input–output network simulation. Communications in Nonlinear Science and Numerical Simulation. 2013; 18 (7):1757-1774.
Chicago/Turabian StyleZhan-Ming Chen; G.Q. Chen. 2013. "Demand-driven energy requirement of world economy 2007: A multi-region input–output network simulation." Communications in Nonlinear Science and Numerical Simulation 18, no. 7: 1757-1774.
This study investigates the virtual water profile of the world in 2004 based on a multi-region input–output model. The water footprints of 112 nation-level regions are calculated and the footprint compositions of major water consumers are analyzed. Less than 35% of the global virtual water requirement is provided by agricultural products, in spite of the fact that 69% of the total water withdrawal is associated with agricultural sector. At the national scale, India, the United States, and mainland China are the world's largest virtual water consumers. Per capita water footprint varies from 30 m3 for Rest of South Central Africa to 3290 m3 for Luxembourg. As one of the major determinants of national footprint, international virtual water trade sums up to 30% of the direct water withdrawal of the world. Meanwhile, results show that 57% of the international virtual water flows is embodied in non-food trade, confirming the importance to take not only food product but also non-food product into account when overall water budget is considered. Mainland China is the world's leading exporter and deficit receiver in terms of virtual water trade (204 Gm3 and 142 Gm3, respectively), in contrast to the United States as the leading importer (178 Gm3) and Japan as the leading surplus receiver (77 Gm3). Finally, the virtual water trade connections of China and the United States with their major trading partners are revealed via introducing the index of virtual water dependency. Results presented in this study are of essential implications for policy making regarding water using pattern adjustment and water security enhancement.
Zhan-Ming Chen; G.Q. Chen. Virtual water accounting for the globalized world economy: National water footprint and international virtual water trade. Ecological Indicators 2012, 28, 142 -149.
AMA StyleZhan-Ming Chen, G.Q. Chen. Virtual water accounting for the globalized world economy: National water footprint and international virtual water trade. Ecological Indicators. 2012; 28 ():142-149.
Chicago/Turabian StyleZhan-Ming Chen; G.Q. Chen. 2012. "Virtual water accounting for the globalized world economy: National water footprint and international virtual water trade." Ecological Indicators 28, no. : 142-149.
This study investigates the fault detection problem for uncertain linear time invariant (LTI) systems subject to polytopic uncertainties, exploiting some properties provided by the observer-based robust fault detection filter (RFDF), which has possible applications in practical power systems. By means of parameter-dependent Lyapunov functions, the existence condition of RFDF is assessed through solving a group of linear matrix inequalities (LMIs). In order to further reduce the conservativeness, an efficient algorithm in terms of LMIs by generating homogeneous polynomial parameter-dependent Lyapunov functions of arbitrary degree on the uncertain parameters is presented, which includes as special case existing conditions for RFDF design. It can be established that as the degree of the polynomial increases, the number of LMIs and free variables increases and the test becomes less conservative. Moreover, the fault sensitivity H− index can be optimized via a convex optimization algorithm, leading to the optimal RFDF. The methodology proposed can also be applied to other relevant aspects such as determining the threshold. An uncertain LTI power system model is adopted as an illustrated example to demonstrate the efficacy of the proposed methods when compared to other methods from the literature.
Shiyun Xu; Yong Tang; Huadong Sun; Bing Zhao; Zhan-Ming Chen. On parameter-dependent Lyapunov functions for robust fault detection filter design with application in power systems. Journal of the Franklin Institute 2012, 349, 2389 -2405.
AMA StyleShiyun Xu, Yong Tang, Huadong Sun, Bing Zhao, Zhan-Ming Chen. On parameter-dependent Lyapunov functions for robust fault detection filter design with application in power systems. Journal of the Franklin Institute. 2012; 349 (7):2389-2405.
Chicago/Turabian StyleShiyun Xu; Yong Tang; Huadong Sun; Bing Zhao; Zhan-Ming Chen. 2012. "On parameter-dependent Lyapunov functions for robust fault detection filter design with application in power systems." Journal of the Franklin Institute 349, no. 7: 2389-2405.
For the world economy as a biophysical network associated with financial links, an ecological endowment inventory and corresponding ecological input–output modeling are presented to investigate the greenhouse gas emissions and natural resources use in 2000. A forty-sector global economic input–output table is constructed through an integration and extension of existing statistics which covers thirty-four countries accounting for about 80% of the world economy. Global inventories for ecological endowments of six categories, i.e., greenhouse gas emissions, energy sources, water resources, exergy resources, solar emergy resources, and cosmic emergy resources, are accounted in detail. As a result of the modeling, embodied intensities of different ecological endowments are obtained for all forty sectors, based on which the sectoral embodiments for consumptive and productive uses are presented separately. Results of this study provide a sound scientific database for policy making on global climate change mitigation as well as on global resources management.
G.Q. Chen; Z.M. Chen. Greenhouse gas emissions and natural resources use by the world economy: Ecological input–output modeling. Ecological Modelling 2011, 222, 2362 -2376.
AMA StyleG.Q. Chen, Z.M. Chen. Greenhouse gas emissions and natural resources use by the world economy: Ecological input–output modeling. Ecological Modelling. 2011; 222 (14):2362-2376.
Chicago/Turabian StyleG.Q. Chen; Z.M. Chen. 2011. "Greenhouse gas emissions and natural resources use by the world economy: Ecological input–output modeling." Ecological Modelling 222, no. 14: 2362-2376.
Presented in this study is an empirical analysis of embodied carbon dioxide emissions induced by fossil fuel combustion for the world divided into three supra-national coalitions, i.e., G7, BRIC, and the rest of the world (ROW), via the application of a multi-region input–output modeling for 2004. Embodied emission intensities for the three coalitions are calculated and compared, with market exchange rate and purchase power parity separately used to investigate the difference between nominal and real production efficiencies. Emissions embodied in different economic activities such as production, consumption, import, and export are calculated and analyzed accordingly, and remarkable carbon trade imbalances associated with G7 (surplus of 1.53 billion tons, or 36% its traded emissions) and BRIC (deficit of 1.37 billion tons, or 51% its traded emissions) and approximate balance with ROW (deficit of 0.16 billion tons, or 3% its traded emissions) are concretely revealed. Carbon leakages associated with industry transfer and international trades are illustrated in terms of impacts on global climate policies. The last but not least, per capita consumption based emissions for G7, BRIC, and ROW are determined as 12.95, 1.53, and 2.22 tons, respectively, and flexible abatement policies as well as equity on per capita entitlement are discussed.
Z.M. Chen; G.Q. Chen. Embodied carbon dioxide emission at supra-national scale: A coalition analysis for G7, BRIC, and the rest of the world. Energy Policy 2011, 39, 2899 -2909.
AMA StyleZ.M. Chen, G.Q. Chen. Embodied carbon dioxide emission at supra-national scale: A coalition analysis for G7, BRIC, and the rest of the world. Energy Policy. 2011; 39 (5):2899-2909.
Chicago/Turabian StyleZ.M. Chen; G.Q. Chen. 2011. "Embodied carbon dioxide emission at supra-national scale: A coalition analysis for G7, BRIC, and the rest of the world." Energy Policy 39, no. 5: 2899-2909.
For ecological economic evaluation based on the unified biophysical matrix this research illustrates an updated emergy synthesis in terms of embodied cosmic exergy instead of embodied solar energy, which successes the foundation of systems ecological theory but changes the starting point for the estimation from simply the sun to the cosmos. According to the modified definition implicating explicit scarcity and strict additivity based on the fundamental thermodynamics laws, the updated emergy approach overcomes the confusable and intractable deficiencies of traditional one and shows firmer theoretical basis as well as better applicability. As a case study for the regional socio-economic ecosystem, a cosmic emergy based ecological economic evaluation of the Beijing urban ecosystem during the period 1978-2004 is presented. The local and external resources supporting the concerned ecosystem are accounted and analyzed in a common unit, i.e., cosmic Joule, according to which a series of indicators are applied to reveal its evolutional characteristics through five aspects as emergy structure, emergy intensity, emergy welfare, environmental impacts, and degree of exploitation and economic efficiency. During the analyzed period, the major emergy source sustaining the operation of the ecosystem had changed from the renewable resources exploited locally to the nonrenewable resources purchased from outside. Emergy intensity for the Beijing urban ecosystem kept rising owing to the continuous investment of resources, which not only improved the living standard but also intensified the environmental pressure. Moreover, the increase of exploitation degree was accompanied with the decline of economic efficiency, while the rising emergy investment ratio implicates that Beijing was at the risks of resources shortage and high dependence on external resources
Jiang Mei Ming; Chen Zhan-Ming; Zhang Bo; Li Shuang Cheng; Xia Xiao Hua; Zhou Shi Yi; Zhou Jiang Bo. Ecological Economic Evaluation Based on Emergy as Embodied Cosmic Exergy: A Historical Study for the Beijing Urban Ecosystem 1978–2004. Entropy 2010, 12, 1696 -1720.
AMA StyleJiang Mei Ming, Chen Zhan-Ming, Zhang Bo, Li Shuang Cheng, Xia Xiao Hua, Zhou Shi Yi, Zhou Jiang Bo. Ecological Economic Evaluation Based on Emergy as Embodied Cosmic Exergy: A Historical Study for the Beijing Urban Ecosystem 1978–2004. Entropy. 2010; 12 (7):1696-1720.
Chicago/Turabian StyleJiang Mei Ming; Chen Zhan-Ming; Zhang Bo; Li Shuang Cheng; Xia Xiao Hua; Zhou Shi Yi; Zhou Jiang Bo. 2010. "Ecological Economic Evaluation Based on Emergy as Embodied Cosmic Exergy: A Historical Study for the Beijing Urban Ecosystem 1978–2004." Entropy 12, no. 7: 1696-1720.