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Estimation of the electromechanical characteristics of power systems based on a revised stochastic subspace method and the stabilization diagram

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Science China(Technological Sciences) 2012年第6期55卷 1677-1687页

作者： NI JingMin SHEN Chen LIU Feng State Key Laboratory of Control and Simulation of Power Systems and Generation Equipments Beijing 100084China

Estimating low-frequency oscillation modes and the corresponding mode shapes based on ambient data from WAMS measurements has a promising prospect in power system analysis and *** on the stochastic subspace method,this paper proposes a revised stochastic subspace method by introducing reference channels,which can estimate the modes and the mode shapes simultaneously with great computational ***,the accuracy of the estimated results is not *** discriminate the real modes from the spurious ones,the stabilization diagram is introduced.A novel algorithm is designed to deal with the stabilization diagram which can detect the real modes *** conducted on the IEEE-118 system indicate that the proposed method has good performance in terms of both computational efficiency and accuracy,and has the potential of being used on-line.

关键词： electromechanical oscillation ambient data stochastic subspace method reference channels stabilization diagram

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A new robust identification method for Xq of synchronous generator with steady-state PMU data

A new robust identification method for Xq of synchronous gen...

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IEEE General Meeting power& Energy Society

作者： Ancheng Xue Junli Zhang Tianshu Bi Shi Chen Wei Tang Shijun Hu State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University Beijing China Electrical Power Company of Anhui Province Electrical Power Dispatching & Control Center of Anhui Hefei Anhui China

This paper proposes a robust on-line identification method for the synchronous generator's quadrature-axis synchronous reactance Xq with steady-state PMU (Phasor Measurement Unit) data. Firstly, the mathematical formulation for identification of Xq, which is a least square estimation with the objective of terminal voltage fiting is introduced. And then, the robust Huber estimation, which can eliminate the effects of gross errors among measured data, is presented. Furthermore, the Huber estimation is applied to identification for Xq by modifying its objective function. simulation results with PSASP data verify the high accuracy and robustness of the proposed method in different situations. Moreover, simulation results with the field data of a 667-MVA generator show the effectiveness of the proposed approaches.

关键词： Synchronous generators Phasor measurement units Robustness Estimation Parameter estimation Steady-state

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Concurrent structural and material optimization of turbine frame in turbo-fan engine

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Hangkong Dongli Xuebao/Journal of Aerospace power 2013年第10期28卷 1274-2180页

作者： Gao, Xi-Guang Liu, Xing-Guo Zhang, Hua-Jun Song, Ying-Dong Jiangsu Province Key Laboratory of Aerospace Power System College of Energy and Power Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China Representative Office Stationed 420 Factory Chinese People's Liberation Army Chengdu 610503 China State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

Based on the traditional structural optimization method, a structural/material optimization method for turbine frame was developed in consideration of the effects of structural parameters and properties of materials on the performance of turbine frame. The original optimization problem was decomposed into structure level and the material level. The first one was solved by feasible direction method while the second problem was solved by parallel genetic algorithms. A distributed computer system was designed by C language and employed to obtain the optimal material combination and structural parameters of one typical turbine frame. The result shows that the structure/material optimization may obtain better design than structure optimization. In the examples, compared with the worst material combination, the mass of the optimal material combination is reduced by 29.0%.

关键词： Turbines

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Real-time electromagnetic transient simulation algorithm for integrated power systems based on network level and component level parallelism

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Science China(Technological Sciences) 2012年第11期55卷 3232-3241页

作者： CHEN LaiJun CHEN Ying MEI ShengWei State Key Laboratory of Control and Simulation of Power Systems and Generation Equipments(Department of Electrical Engineering Tsinghua University)Beijing 100084China

The analysis and simulation of power system are becoming more and more challenging as the complexity of system topology and components has been increased. In this paper, a hybrid parallel algorithm is proposed for the real-time electromagnetic transient simulation （EMTS） of integrated power systems containing multiphase machines. The proposed algorithm is com- posed of a novel network partition method called component level parallelization and the Multi-Area Thevenin Equivalent （MATE） method, which extends the flexibility of the network partition in parallel simulation. Moreover, several methods are developed to enhance the efficiency of the communication and computation. power systems with up to 410 single-phase elec- trical nodes and 336 switches are simulated in a time step of 50 ~ts to validate the proposed algorithm.

关键词： EMTP multiphase machine network partition parallel computing power system real-time simulation

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Research focuses and advance technologies of smart grid in recent years

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Chinese Science Bulletin 2012年第22期57卷 2879-2886页

作者： MEI ShengWei CHEN LaiJun State Key Laboratory of Control and Simulation of Power Systems and Generation Equipments Department of'Electrical EngineeringTsinghuaUniversityBeijing 100084China

The smart grid is attracting more and more attention in electrical engineering for its promising ***,huge challenges also exist in the implementations of the smart grid,such as high penetration of renewable energy resources,low carbon electricity and cyber-physical security,*** this paper,the latest progress of some research focuses and advance technologies in the development of smart grid is reviewed.

关键词：电网智能技术网络物理安全可再生能源电气工程渗透力

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Design and implementation of photovoltaic lighting system with high luminous efficacy LEDs

Design and implementation of photovoltaic lighting system wi...

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2012 IEEE 7th International power Electronics and Motion control Conference - ECCE Asia, IPEMC 2012

作者： Yuan, Liqiang Chen, Zhiping Hu, Xianlai Ge, Junjie Zhao, Zhengming State Key Laboratory of Control and Simulation of Power System and Generation Equipment Department of Electrical Engineering Tsinghua University Beijing China

ISBN: (纸本)9781457720864

With the background park lighting application, and based on the characteristics of advanced devices in the system, this paper studies the photovoltaic (PV) light emitted diode (LED) lighting system in three main aspects, which are the design of the whole system, hybrid control strategy combining the maximum power point tracing (MPPT, for PV panels) with the energy management(for battery), and LED driving and dimming. Taking the example of an actual 50W high luminous efficacy LED system, the design, implantation and experiments are described in detail. In addition, the long-term measurement results in real environment are illustrated in this paper. © 2012 IEEE.

关键词： Solar panels

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Self-precharge of floating capacitors in a five-level ANPC inverter

Self-precharge of floating capacitors in a five-level ANPC i...

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2012 IEEE 7th International power Electronics and Motion control Conference - ECCE Asia, IPEMC 2012

作者： Wang, Kui Li, Yongdong Zheng, Zedong Xu, Lie Ma, Hongwei State Key Laboratory of Control and Simulation of Power System and Generation Equipments Department of Electrical Engineering Tsinghua University Beijing China

ISBN: (纸本)9781457720864

Five-level active neutral-point-clamped (ANPC) converter is a newly emerging topology which can overcome the drawbacks of traditional neutral-point-clamped and flying-capacitor multilevel converters. During the start-up of the converter, it must be ensured that the switches and capacitors cannot be overvoltage and overcurrent due to the uncharged floating capacitors. In this paper, a floating capacitor self-precharge method is proposed which, by transferring the circuit into a booster, charges the floating capacitors to the reference voltage with a very small average load current. simulation and experimental results are presented to verify the validity of this method. © 2012 IEEE.

关键词： power converters

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Excavator Energy-saving Efficiency Based on Diesel Engine Cylinder Deactivation Technology

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Chinese Journal of Mechanical Engineering 2012年第5期25卷 897-904页

作者： YANG Jing QUAN Long YANG Yang Key Laboratory of Advanced Transducers and Intelligent Control System of Ministry of Education Taiyuan University of Technology Taiyuan 030024 China The State Key Lab of Fluid Power Transmission and Control Zhejiang University Hangzhou 31002 7 China

The hydraulic excavator energy-saving research mainly embodies the following three measures： to improve the performance of diesel engine and hydraulic component, to improve the hydraulic system, and to improve the power matching of diesel-hydraulic system-actuator. Although the above measures have certain energy-saving effect, but because the hydraulic excavator load changes frequently and fluctuates dramatically, so the diesel engine often works in high-speed and light load condition, and the fuel consumption is higher. Therefore, in order to improve the economy of diesel engine in light load, and reduce the fuel consumption of hydraulic excavator, energy management concept is proposed based on diesel engine cylinder deactivation technology. By comparing the universal characteristic under diesel normal and deactivated cylinder condition, the mechanism that fuel consumption can be reduced significantly by adopting cylinder deactivation technology under part of loads condition can be clarified. The simulation models for hydraulic system and diesel engine are established by using AMESim software, and fuel combustion consumption by using cylinder-deactivation-technology is studied through digital simulation approach. In this way, the zone of cylinder deactivation is specified. The testing system for the excavator with this technology is set up based on simulated results, and the results show that the diesel engine can still work at high efficiency with part of loads after adopting this technology; fuel consumption is dropped down to 11% and 13% under economic and heavy-load mode respectively under the condition of driving requirements. The research provides references to the energy-saving study of the hydraulic excavators.

关键词： diesel engine cylinder deactivation hydraulic excavator energy-saving

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Application of fuzzy-rough set theory and improved SMO algorithm in aircraft engine vibration fault diagnosis

Application of fuzzy-rough set theory and improved SMO algor...

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2012 3rd Annual IEEE Prognostics and system Health Management Conference, PHM-2012

作者： Xu, Hongzhi Jiang, Dongxiang Liang, Lei State Key Laboratory of Control and Simulation of Power System and Generation Equipment Department of Thermal Engineering Tsinghua University Beijing 100084 China

Aircraft engine is an important component of the airplane, which lifespan and reliability have directly influence to flight safety. Vibration analysis is an effective fault diagnosis method for airplane's mechanical construction fault. Several typical vibration faults have drawn from the vibration analysis on the basis of fault mechanism in aircraft engine, and the standard vibration fault-symptom (Fuzzy Membership) relationship table have constructed based on Fuzzy Mathematic theory in this paper. Sample data are simulated on the basis of this table. Sequential Minimal Optimization (SMO) is a fast algorithm for training Support Vector Machines (SVM). The simulated result showed a great improvement on computation efficiency by selecting double threshold parameter for SMO algorithm than single threshold. In order to examine the algorithm's effect applying in the aircraft engine fault diagnosis, Radial Basis Function (RBF) Neural Network, C4.5 Decision Tree, SVM (chunking), Platt's SMO and Improved SMO algorithm are applied to the training data and test data. It is shown that the Improved SMO algorithm displayed superior comprehensive performance. Finally, the vibration fault feature is reduced based on Fuzzy-Rough Sets theory. The research shows that the Improved SMO algorithm is quicker than other algorithm in aircraft engine fault diagnosis with the reduced feature attributes, and its accuracy is high. © 2012 IEEE.

关键词： Support vector machines

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Battery energy storage system load shifting control based on real time load forecast and dynamic programming

Battery energy storage system load shifting control based on...

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2012 IEEE International Conference on Automation Science and Engineering: Green Automation Toward a Sustainable Society, CASE 2012

作者： Bao, Guannan Lu, Chao Yuan, Zhichang Lu, Zhigang State Key Laboratory of Control and Simulation of Power System and Generation Equipments Tsinghua University Beijing 100084 China Electric Power Research Institute China Southern Power Grid Guangzhou 510080 China

ISBN: (纸本)9781467304283

Battery energy storage system (BESS) is one of the key technologies for smart grid and load shifting is one of the fundamental functions of BESS. BESS load shifting performance is determined by the availability of accurate load curves and optimization approaches. In this paper, a real-time control strategy based on load forecast and dynamic programming methods is presented. The predicted load curve is updated on-line through regress forecasting. The proposed optimization model is solved by using dynamic programming technique. The objective is peak shaving and prolonging the battery lifetime, and the constraints considered include battery state-of-charge (SOC), cycling times per day, converter capacity and step power. The above control strategy was successfully applied to the 5MW*4hour lithium-Ion BESS demonstration project in Biling substation, China Southern power Grid. The simulation results based on the actual load data of Biling substation demonstrate the effectiveness. © 2012 IEEE.

关键词： Dynamic programming

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