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An architecture description language based on dynamic description logics for self-healing systems

International Journal of Advancements in Computing Technology 2012年第18期4卷 89-96页

作者： Wang, Zhuxiao Peng, Hui Guo, Jing Wu, Kehe Cui, Wenchao Wang, Xiaofeng School of Control and Computer Engineering State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University Beijing 102206 China Education Technology Center Beijing International Studies University Beijing 100024 China National Computer Network Emergency Response Technical Team/Coordination Center of China Beijing 100029 China School of Control and Computer Engineering Institute of Electric Information Security Engineering Research Center of Power Information North China Electric Power University Beijing 102206 China Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China

As biological systems exhibit adaptation, healing and robustness in the face of changing environmental behavior, this paradigm has actuated research dealing with the concept of self-healing systems, which attempt to heal themselves in the sense of recovering from malicious attacks and rectifying of system faults. The goal of self-healing systems is to provide survivable systems that require high dependability, robustness, adaptability, and availability. Such systems maintain one or more models, whether external or internal, at run time as a basis for identifying problems and resolving them. This article describes an architectural description language, called ADML, which is being developed as a new formal language and/or conceptual model for representing evolving software architectures. The ADML embraces dynamic change as a fundamental consideration, supports a broad class of adaptive changes at the architectural level, and offers a uniform way to represent and reason about both static and dynamic aspects of self-healing systems. Because the ADML is based on the Dynamic Description Logic DDL(SHON (D)), which can represent both dynamic semantics and static semantics under a unified logical framework, architectural ontology entailment for the ADML languages can be reduced to knowledge base satisfiability in DDL(SHON (D)), and dynamic description logic algorithms and implementations can be used to provide reasoning services for ADML. In this article, we present the syntax of ADML, explain its underlying semantics using the Dynamic Description Logic DDL(SHON (D)), and exemplify our approach by applying it to the domain of load balancing a wireless remote-access system;the preliminary results certify the potential of the approach.

关键词： Formal languages

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Cooperative grid modeling for interconnected multilevel multi-area power systems

Cooperative grid modeling for interconnected multilevel mult...

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International Conference on Electric Utility Deregulation and Restructuring and power Technologies

作者： Jia-An, Zhang Na, Zhang Key Laboratory of Power System Simulation and Control of Ministry of Education Tianjin University Tianjin 300072 China

ISBN: (纸本)9781457703638

With the formation of large-scale interconnected power systems, the grid structure and operation mode are becoming increasingly complicated. Currently, the power network model is maintained by distribution centers respectively according to the scope of jurisdiction. For power system analysis, the model data of the whole network is necessary, while only the internal data is transparent to a distribution center and the external data is not accessible directly. Therefore, the model data from distribution centers must be integrated in a high-level distribution center. Such a traditional approach cannot meet the efficiency requirements for large power grid analysis. This paper presents a method of network data modeling and maintenance for multi-level multi-area power systems, in which the local model data are maintained in each distribution center, the connection model is maintained in a higher level of distribution center, and all centers work cooperatively. In a distribution center, the graphic modeling tools should be supported and the local model data can be maintained manually or exported from the EMS. In the method, some technologies are considered, such as model data interfacing, version management, model data maintenance, etc. Cooperative modeling is helpful to improve the analysis efficiency and to reduce the burden of model data maintenance for large power grids. © 2011 IEEE.

关键词： Data integration

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Analysis of directional pilot protection on transmission line with wind farm integration

Analysis of directional pilot protection on transmission lin...

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2011 International Conference on Advanced power system Automation and Protection, APAP 2011

作者： Li, Bin Lin, Meng Key Laboratory of Power System Simulation and Control of Ministry of Education Tianjin University Tianjin 300072 China

ISBN: (纸本)9781424496198

Increased integration of wind power makes higher demands on the stability and protection of power system. Wind farms are connected to power grid through transmission line. When single-phase fault occurs on the line, positive and negative sequence currents are not equal and are much smaller than zero sequence current. Phase selector based on the theory of current- difference sudden-change may mistake single-phase fault for phase-to-phase fault because positive and negative branch coefficients are not equal. Considering a case of mal-operation of directional pilot protection, the paper studies the impedance characteristics of asynchronous wind generator, analyzes the causes of weak feed and different branch coefficients, and explains their contribution to fault phase selector's mal-operation. The results are validated by simulation and an improvement for fault phase selection with wind farm integration is proposed. © 2011 IEEE.

关键词： Electric lines

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simulation of shunt active power filter using modified SVPWM control method

Simulation of shunt active power filter using modified SVPWM...

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2011 International Conference on Electric and Electronics, EEIC 2011

作者： Wang, Jidong Yang, Guanqing Liu, Kun Key Laboratory of Power System Simulation and Control Ministry of Education Tianjin University Tianjin 300072 China

ISBN: (纸本)9783642216961

Space vector pulse width modulation (SVPWM) was widely used in inverter control for the advantages of fixed switching frequency, full utilization of DC-link voltage and better control precision. In recent years, SVPWM is gradually applied in the control method of active power filter (APF) as the APF mains is just one invert. The voltage vectors are composed based on the α-β axis in traditional SVPWM however, in this paper one x-y composed reference axis at 60 degree angles from each other is used instead. Compared with traditional method, the principle of the method is relatively simple and easy to implement. At the same time PI regulator is adopted for the DC-link voltage control. Finally simulation results show that the APF has a better compensation effect using this control method. © 2011 Springer-Verlag Berlin Heidelberg.

关键词： Bandpass filters

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A parallel based real-time electromagnetic transient simulator for IPS

A parallel based real-time electromagnetic transient simulat...

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Electric Ship Technologies Symposium

作者： Gong, Yuan Chen, Laijun Chen, Ying Xu, Yin State Key Laboratory of Control and Simulation of Power System and Generation Equipments Department of Electrical Engineering Tsinghua University Beijing China

ISBN: (纸本)9781424492725

IPS has many special characteristics, such as using multi-phase, multi-frequency and hybrid AC/DC devices. As a result, existing electromagnetic transient simulators developed for power systems on land do not apply to IPS. This paper aims to build up a parallel based real-time electromagnetic transient simulator for IPS. A fast multi-switching process method for parallel electromagnetic transient simulations is coined to handle the tremendous switch events in IPS. To solve the difficulties brought by multi-phase machines in IPS, a multilevel hybrid parallel algorithm is forged through the combination of component level and network level parallelization. Based on the key techniques mentioned above, a parallel simulator is built up. Through sufficient testing to typical examples of IPS, the accuracy and high-efficiency of the simulator are proved. © 2011 IEEE.

关键词： Simulators

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Constant voltage control on DC bus of PV system with flywheel energy storage source (FESS)

Constant voltage control on DC bus of PV system with flywhee...

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2011 International Conference on Advanced power system Automation and Protection, APAP 2011

作者： Zhang, HuiZhi Li, YongLi Key Laboratory of Power System Simulation and Control of Ministry of Education Tianjin University Tianjin 300072 China

ISBN: (纸本)9781424496198

Fluctuation of the voltage is always the major barrier to the effective application of photovoltaic energy. In this paper, the flywheel energy storage system (FESS) is added to PV system. Considering the fluctuation of photovoltaic energy and limitation of flywheel capacity, flywheel may store energy from the photovoltaic source or AC system, or release energy to load in order to maintain the stable voltage on DC bus. Five different system operating modes and corresponding control strategies are presented in this paper. Corresponding to the different system operating modes, simulation has been done and the control strategies of FESS have been proved valid. © 2011 IEEE.

关键词： Flywheels

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Application of a combined system to enhance power quality in an island microgrid

Application of a combined system to enhance power quality in...

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2011 IEEE power Engineering and Automation Conference, PEAM 2011

作者： Ma, Zhengbo Li, Linchuan Dong, Tuo Key Laboratory of Power System Simulation Control of Ministry of Education Tianjin University Tianjin 300072 China

ISBN: (纸本)9781424496884

Efficient and effective use of renewable energy, distributed generation and energy storage can solve global problems such as energy crisis and climate change. A promising solution to interconnecting these distributed energy resources with the utility grid is the microgrid paradigm. Due to the dispersion of distributed sources and loads, different distributed sources use the different control strategies. Microgrid is usually interconnected with the utility grid by the inverter, which causes to many current harmonics in the export of the inverter. Without the support of the utility grid, the variation of reactive power of the loads in the island microgrid will lead to voltage fluctuation. Under the premise of assuming that the microsource could supply adequate active power to the loads, this paper proposes a combined system constructed by Shunt Active power Filter (SAPF) and Static Var Compensator (SVC) to improve the power quality of the island microgrid, in which SAPF uses the positive sequence method for harmonic detection and uses Hysteresis control method for current tracking control and is adopted near the microsource to mitigate harmonic currents and SVC is set near the load to compensate reactive power so as to relieve the voltage variation. simulation results show the effectiveness of the combined system. © 2011 IEEE.

关键词： Static Var compensators

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Research on fractional order controller based on best rational approximation approach

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Journal of Convergence Information Technology 2012年第4期7卷 50-58页

作者： Zhao, Huimin Nie, Bing Li, Wen Deng, Wu Software Institute Dalian Jiaotong University Dalian 116028 China Key Laboratory of Numerical Simulation in the Sichuan Provincial College Neijiang Normal University Neijiang 641112 China Artificial Intelligence Key Laboratory of Sichuan Province Sichuan University of Science and Engineering Zigong 643000 China State Key Laboratory of Power Transmission Equipment and System Security and New Technology College of Electrical Engineering Chongqing University Chongqing 400044 China Key Laboratory of advanced Design and Intelligent Computing Dalian University Ministry of Education Dalian 116622 China

Introduce the basic concept of best rational approximation and constructing procedure of the best rational approximation function in Laplace domain. By an illustrative example the design method of FOC based on best rational approximation is discussed. The performance comparison of transfer functions between the FOC obtained by best rational approximation method and conventional PID shows that it is effective to apply the method in design of FOC, which can guarantee maximum absolute error of amplitude frequency characteristic of approximation function in a given error tolerance.

关键词： Rational functions

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simulation of voltage sag detection method based on DQ transformation

Simulation of voltage sag detection method based on DQ trans...

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2011 International Conference on Electric and Electronics, EEIC 2011

作者： Wang, Jidong Liu, Kun Yang, Guanqing Key Laboratory of Power System Simulation and Control Ministry of Education Tianjin University Tianjin 300072 China

ISBN: (纸本)9783642216961

The rapid detection of characteristics of voltage sag is an important prerequisite for using dynamic voltage restorer (DVR) for voltage compensation. This paper introduced an improved derivation detection method based on dq transformation. simulation was performed to analyze the advantages and disadvantages of both methods and compare them. Results showed that the improved detection method had shorter delay and better waveform of detection and met the requirements of accuracy and timeliness better. © 2011 Springer-Verlag Berlin Heidelberg.

关键词： Voltage regulators

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A predictive DC voltage control scheme for back-to-back converters based on energy balance modeling

A predictive DC voltage control scheme for back-to-back conv...

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2011 International Conference on Electrical Machines and systems, ICEMS 2011

作者： Yin, Lu Zhao, Zhengming Lu, Ting He, Fanbo Yuan, Liqiang State Key Laboratory of Control and Simulation of Power System and Generation Equipment Department of Electrical Engineering Tsinghua University Beijing 100084 China

ISBN: (纸本)9781457710445

This paper presents a predictive control scheme of DC-link voltage for back-to-back converters based on energy balance modeling. Since the variation of DC-link voltage is affected by the energy mismatch between rectifier and inverter, the energy distribution in a rectifier-inverter is analyzed. Moreover, in order to calculate the input and output energy in one control period accurately, the grid current is regulated by predictive control and the instantaneous active power consumed by the induction motor is estimated. Then, an equation based on energy balance in one control period is established, and the DC-link voltage can be controlled by solving it. Finally, simulation results show that with the proposed control scheme, the back-to-back converter exhibits both good dynamic and steady-state performances. © 2011 IEEE.

关键词： Energy balance

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