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Dynamic extending nonlinear H_∞ control and its application to hydraulic turbine governor

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Science China(Technological Sciences) 2007年第5期50卷 618-635页

作者： MEI ShengWei GUI XiaoYang SHEN Chen LU Qiang State Key Laboratory of power System Department of Electrical Engineering Tsinghua University Beijing 100084 China State Key Laboratory of Power System Department of Electrical Engineering Tsinghua University Beijing 100084 China State Key Laboratory of Power System Department of Electrical Engineering Tsinghua University Beijing 100084 China State Key Laboratory of Power System Department of Electrical Engineering Tsinghua University Beijing 100084 China

There exists a large class of nonlinear systems with uncertainties, such as hydrau- lic turbine governors, whose robust control problem is hard to solve by means of the existing robust control approaches. For this class of systems, this work pre- sents a dynamic extending H∞ controller via both differential geometry and H∞ the- ory. Furthermore, based on differential game theory, it has been verified that the proposed control strategy has robustness in the sense that the disturbance can be attenuated effectively because the L2-gain from the disturbance input to the regu- lation output signal could be reduced to any given level. Thirdly, a robust control strategy for hydraulic turbine governor is designed according to the proposed ex- tending H∞ control method, and has been developed into a real control equipment. Finally the field experiments are carried out which show clearly that the developed control equipment can enhance transient stability of power systems more effec- tively than the conventional controller.

关键词： dynamic extending H∞ control, nonlinear system, robust control, hydraulic turbine governor

Graph Theory Based N-1 Transmission Contingency Selection and Its Application in Security-constrained Unit Commitment

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Journal of Modern power Systems and Clean Energy 2021年第6期9卷 1458-1467页

作者： Lu Nan Yikui Liu Lei Wu Tianqi Liu Chuan He College of electrical engineering Sichuan University the department of electrical and Computer engineering Stevens Institute of Technology department of electrical and Computer engineering Stevens Institute of Technology

Contingency analysis is an important building block in the stability and reliability analysis of power grid operations. However, due to the large number of transmission lines,in practice only a limited number of contingencies could be evaluated. This paper proposes a graph theory based N-1 contingency selection method to effectively identify the most critical contingencies, which can be used in security-constrained unit commitment(SCUC) problems to derive secure and economic operation decisions of the power grid. Specifically, the power flow transferring path identification algorithm and the vulnerability index are put forward to rank individual contingencies according to potential transmission line overloads. Effectiveness of the proposed N-1 contingency selection method is quantified by applying the corresponding SCUC solution to the full N-1 security evaluation, i. e., quantifying total post-contingency generation-load imbalance in all N-1 contingencies. Numerical results on several benchmark IEEE systems, including5-bus, 24-bus, and 118-bus systems, show effectiveness of the proposed method. Compared with existing contingency selection methods which usually resort to full power flow calculations,the proposed method relies on power gird topology to effectively identify critical contingencies for facilitating the optimal scheduling of SCUC problems.

关键词： Concentric relaxation contingency analysis graph theory security-constrained unit commitment(SCUC) shortest path vulnerability index

Interruptible Load Scheduling Model Based on an Improved Chicken Swarm Optimization Algorithm

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CSEE Journal of power and Energy Systems 2021年第2期7卷 232-240页

作者： Jinsong Wang Fan Zhang Huanan Liu Jianyong Ding Ciwei Gao department of electrical Computerand Systems EngineeringCase Western Reserve UniversityCleveland Ohio 44106USA department of electrical engineering Northeast Electric Power UniversityJilin 132012China School of electrical engineering Southeast UniversityNanjing 210096China

With the continuous growth of the tertiary industry and residential loads,balancing the power supply and consumption during peak demand time has become a critical *** studies try to alleviate peak load by increasing power generation on the supply *** to the short duration of peak load,this may cause redundant installation ***,others attempt to shave peak demand by installing energy storage ***,the aforementioned research did not consider interruptible load regulation when optimizing system *** fact,regulating interruptible load has great potential for reducing system peak *** this paper,an interruptible load scheduling model considering the user subsidy rate is first proposed to reduce system peak load and operational *** model has fully addressed the constraints of minimum daily load reduction and user interruption load *** that,by taking a community in Shanghai as an example,the improved chicken swarm optimization algorithm is applied to solve the interruptible load scheduling ***,the simulation results validate the efficacy of the proposed optimization algorithm and indicate the significant advantages of the proposed model in alleviating the peak load and reducing operational costs.

关键词： Demand response improved Chicken Swarm Optimization algorithm interruptible load scheduling model peak load user subsidy rate

An optimized transmission line model of grounding electrodes under lightning currents

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Science China(Technological Sciences) 2013年第2期56卷 335-341页

作者： YANG Lin WU GuangNing CAO XiaoBin School of electrical engineering Southwest Jiaotong University Sichuan power electrical Research Institute

In this paper, an optimized transmission line model （OTL） for modeling transient behavior of grounding electrodes under lightning currents is presented. The soil ionization effect is considered in OTL, and all electromagnetic couplings between dif- ferent parts of grounding electrode are also considered by selecting the size of segment conductor properly and calculating the mutual coupling parameters between segment conductors accurately. Comparing with the traditional transmission line model, the optimized model can be used to accurately predict the effective length and transient potential rise （TPR） of grounding elec- trodes. Transient behaviors of grounding electrodes are simulated by OTL and the results are in good agreement with those of the electromagnetic model proposed by Grcev, and experiment results performed by Electricit6 de France and Geri. Further- more, non-uniform discharging phenomenon of grounding electrode under lightning current is discussed, and the effective lengths of horizontal grounding electrode under lightning currents are presented.

关键词： grounding electrode lightning current transmission line model electromagnetic mutual coupling

State identification of home appliance with transient features in residential buildings

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Frontiers in Energy 2022年第1期16卷 130-143页

作者： Lei YAN Runnan XU Mehrdad SHEIKHOLESLAMI Yang LI Zuyi LI electrical and Computer engineering department Illinois Institute of TechnologyChicagoIL 60616USA School of electrical engineering Northeast Electric Power UniversityJilin 132012China

Nonintrusive load monitoring(NILM)is crucial for extracting patterns of electricity consumption of household appliance that can guide users9 behavior in using electricity while their privacy is *** study proposes an online method based on the transient behavior of individual appliances as well as system steady-state characteristics to estimate the operating states of the *** determines the number of states for each appliance using the density-based spatial clustering of applications with noise(DBSCAN)method and models the transition relationship among different *** states of the working appliances are identified from aggregated power signals using the Kalman filtering method in the factorial hidden Markov model(FHMM).Thereafter,the identified states are confirmed by the verification of system states,which are the combination of the working states of individual *** verification step involves comparing the total measured power consumption with the total estimated power *** use of transient features can achieve fast state inference and it is suitable for online load *** proposed method was tested on a high-resolution data set such as Labeled hlgh-Frequency daTaset for Electricity Disaggregation(LIFTED)and it outperformed other related methods in the literature.

关键词： nonintrusive load monitoring(NILM) load disaggregation online load disaggregation Kalman filtering factorial hidden Markov model(FHMM) Labeled hlgh-Frequency daTaset for Electricity Disaggregation(LIFTED)

Impacts of multiple demand-side management strategies on microgrids planning:a literature survey

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Clean Energy 2024年第1期8卷 36-54页

作者： Rasha Elazab Ahmed T.Abdelnaby A.A.Ali electrical power and Machines department Faculty of Engineering at Helwan UniversityCairoEgypt

Demand-side management(DSM)schemes play a crucial role in managing renewable energy generation and load fluctuations by uti-lizing demand-response programmes(DRPs).This paper aims to provide a detailed overview of DRPs that help microgrid operators to keep costs and reliability within acceptable ***,this review paper provides a detailed economic load model for DRPs based on initial load,demand-response(DR)incentive,DR penalty and elasticity *** article also aims to guide researchers in identifying research gaps in DSM applications in microgrids by comparing various DSM schemes from different countries and regions in terms of DSM strategies,objective functions and optimization ***,this study analyses the impact of DRPs on microgrid configuration from the perspective of utilities and customers,considering technical and economic performance *** a result,it can be concluded that none of the studied cases provides models or guidelines for choosing appropriate DSM schemes that consider different consumer interests or load-type ***,a few researchers have addressed the features of a modern price-based DR strategy,renewable generation-based dynamic pricing DR,which offers higher customer satisfaction than traditional DRPs.

关键词： demand-side management optimal sizing demand-response strategies renewable generation-based dynamic pricing

Takagi-Sugeno fuzzy model identification for turbofan aero-engines with guaranteed stability

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Chinese Journal of Aeronautics 2018年第6期31卷 1206-1214页

作者： Ruichao LI Yingqing GUO Sing Kiong NGUANG Yifeng CHEN School of power and Energy Northwestern Polytechnical University department of electrical and Computer engineering The University of Auckland

This paper is concerned with identifying a Takagi-Sugeno（TS） fuzzy model for turbofan aero-engines working under the maximum power status（non-afterburning）. To establish the fuzzy system, theoretical contributions are made as follows. First, by fixing antecedent parameters, the estimation of consequent parameters in state-space representations is formulated as minimizing a quadratic cost function. Second, to avoid obtaining unstable identified models, a new theorem is proposed to transform the prior-knowledge of stability into constraints. Then based on the aforementioned work, the identification problem is synthesized as a constrained quadratic *** solving the constrained optimization, a TS fuzzy system is identified with guaranteed ***, the proposed method is applied to the turbofan aero-engine using simulation data generated from an aerothermodynamics component-level model. Results show the identified fuzzy model achieves a high fitting accuracy while stabilities of the overall fuzzy system and all its local models are also guaranteed.

关键词： Constrained optimization Fuzzy system Stability System identification Turbofan engine

Numerical Analysis of MHD Accelerator with Non-Equilibrium Air Plasma

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Plasma Science and Technology 2012年第12期14卷 1110-1115页

作者： M.ANWARI H.H.QAZI SUKARSAN N.HARADA electrical engineering department Umm Al-Qura University Faculty of electrical engineering Universiti Teknologi Malaysia Faculty of electrical engineering Universitas Islam "45" Bekasi department of electrical engineering Nagaoka University of Technology

Magnetohydrodynamic （MHD） accelerator is proposed as a next generation propulsion system. It can be used to increase the performance of a propulsion system. The objective of this study is to investigate the performance of MHD accelerator using non-equilibrium air plasma as working gas. In this study, the fundamental performance of MHD accelerator such as flow performance and electrical performance is evaluated at different levels of applied magnetic field using I-D numerical simulation. The numerical simulation is developed based on a set of differential equations with MHD approximation. To solve this set of differential equations the MacCormack scheme is used. A specified channel designed and developed at NASA Marshall Space Flight Centre is used in the numerical simulation. The composition of the simulated air plasma consists of seven species, namely, N2, N, O2, O, NO, NO＋, and e-. The performance of the non-equilibrium MHD accelerator is also compared with the equilibrium MHD accelerator.

关键词： MHD accelerator Faraday type connection non-equilibrium air plasma

Integrated traffic-power simulation framework for electric vehicle charging stations based on cellular automaton

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Journal of Modern power Systems and Clean Energy 2018年第4期6卷 816-820页

作者： Yue XIANG Zipeng LIU Jichun LIU Youbo LIU Chenghong GU College of electrical engineering and Information Technology Sichuan University State Key Laboratory of electrical Insulation and power Equipment School of Electrical Engineering Xi'an Jiaotong University department of Electronic and electrical engineering University of Bath

This paper presents a novel integrated framework for simulating the charging load of an electric vehicle charging station. The framework is built based on the cellular automaton model, including five modules: vehicle generation, charging station, lane change, speed update and boundary clear. The proposed framework can effectively stimulate the system dynamics of the traffic system and charging power process in a charging station. Case studies have verified its feasibility and effectiveness.

关键词： Charging station Charging load Traffic flow Simulation Cellular automaton