Browsing by Author "Liu, Junyong"

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    Agricultural Load Modeling Based on Crop Evapotranspiration and Light Integration for Economic Operation of Greenhouse Power Systems
    (Chinese Society for Electrical Engineering (CSEE) in collaboration with CEPRI (China Electric Power Research Institute) and IEEE, 2019-12-07) Li, Zeming; Liu, Junyong; Xiang, Yue; Zhang, Xin; Chai, Yanxin
    The threat of environmental degradation attracts great attention to clean energy production and transportation. However, the limited scope of energy consumption causes large-scale of clean energy sources to be abandoned in Sichuan province. In the meantime, the development of modern greenhouse cultivation has transformed the agriculture industry to have a brand-new type of electrical load in the grid. Consequently, the agricultural load can be used to consume the clean energy while facilitating plant growth. In this paper, an innovative agricultural load model is proposed based on crop evapotranspiration and daily light integration. Furthermore, the proposed agricultural load model is also applied to investigate the electricity consumption of five types of crop planting. The results illustrate that the power consumption is primarily driven by artificial lighting compensation system.
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    Chance-constrained optimal dispatch of integrated electricity and natural gas systems considering medium and long-term electricity transactions
    (IEEE, 2019-08-01) Wu, Gang; Xiang, Yue; Liu, Junyong; Zhang, Xin; Tang, Shuoya
    A novel stochastic optimal dispatch model considering medium and long-term electricity transaction for a wind power integrated energy system by using chance constrained programming is proposed. The electricity contract decomposition problem is introduced into the day-ahead optimal dispatch plan formulation progress. Considering the case that decomposition results may be not executable in the dispatch plan, a coordinated optimization strategy based on Lagrange multiplier is proposed to locate the infeasible factors and eliminate the non executable electric quantity. At the same time, the uncertainties and correlation of wind power are considered in the dispatch model, and the original stochastic dispatch problem is transformed into a mixed integer second-order cone programming problem based on second-order cone relaxation and deterministic transformation of chance constraints. Case study results demonstrate the validity of the proposed method
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    An explicit formula based estimation method for distribution network reliability
    (IEEE, 2019-10-31) Xiang, Yue; Su, Yunche; Wang, Yang; Liu, Junyong; Zhang, Xin
    An improved explicit estimation algorithm is proposed for reliability estimation of distribution network. Firstly, hierarchical clustering is used to identify and cluster typical feeders based on topology structure. Secondly, the explicit formula of reliability indices under each typical feeder topology is derived by regression analysis, to establish the model for network reliability estimation. Numerical simulations show the suitability of the proposed method in obtaining accurate reliability index for diversified network topology.
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    Reactive coordinated optimal operation of distributed wind generation
    (Elsevier, 2020-11-26) Xiang, Yue; Zhou, Lili; Huang, Yuan; Zhang, Xin; Liu, Youbo; Liu, Junyong
    Large-scale distributed wind generation (DWG) integration brings new challenges to the optimal operation of the distribution network. The reactive supports from wind turbines (WTs) and reactive power resources can improve both the operation economy and renewable energy consumption. In this paper, a multi-period reactive coordinated optimal operation model for DWG in the distribution network is established. The active-reactive power coordination characteristics of two typical types of WTs are considered and the operating strategy of reactive power resources is integrated in the model. The second-order cone programming (SOCP) is developed to transform the original nonlinear power flow model into a linear and convex model, which would significantly improve the power flow calculation efficiency for DWG penetrated distribution network. The simulation results show that the integration of reactive power resources can further promote the consumption of DWG and improve the operating profits of the distribution network.
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    Techno-economic design of energy systems for airport electrification: a hydrogen-solar-storage integrated microgrid solution
    (Elsevier, 2021-01-02) Xiang, Yue; Cai, Hanhu; Liu, Junyong; Zhang, Xin
    Can aviation really become less polluting? The electrification of airport energy system as a micro-grid is a promising solution to achieve zero emission airport operation, however such electrification approach presents the engineering challenge of integrating new energy resources, such as hydrogen supply and solar energy as attractive options to decarbonize the present system. This paper explores the techno-economic benefits of integrating hydrogen supply, electric auxiliary power unit (APU) of aircraft, electric vehicles, photovoltaic energy (PV), and battery storage system into electrified airport energy system. The hydrogen fuel cell generation provides great flexibility to supply aircraft at remote stands, and reduces the carbon emissions caused by traditional fuel-powered APU. A mixed integer linear programming optimization method based on life cycle theory is developed for capacity sizing of hydrogen energy system, PV and battery storage, with optimization objective of minimizing the total economic costs as well as considering environmental benefits of the proposed airport microgrid system. Case studies are conducted by five different energy integration scenarios with techno-economic and environmental assessments to quantify the benefits of integrating hydrogen and renewable energy into airport. Compared with the benchmark scenarios, the integration of hydrogen energy system reduced the total annual costs and carbon emissions of airport energy system by 41.6% and 67.29%, respectively. Finally, sensitivity analysis of key system parameters such as solar irradiance, grid emission factor, elctricity price, carbon tax, unit investment cost of hydrogen energy system have been investigated to inform the design of hydrogen-solar-storage integrated energy system for future airport electrification.