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第七届亚太防雷国际会议

作者： Zhanqing Yu Zhizhao Li Qian Li Chijie Zhuang Rong Zeng Yong Zhang Yongli Liao State Key Lab of Control and Simulation of Power Systems and Generation EquipmentsDepartment of Elec Department of Mathematical Sciences Tsinghua UniversityHaidian DistrictBeijing 100084China Electric Power Research Institute CSGGuangzhou China

Lightning is a major cause of power interruptions in power transmission *** the Leader Progression Model is an advanced method to evaluate the shielding failure probability of transmission *** the surface electric field on phase conductors and ground wires precisely is important, because the surface electric field has great effect on the upward leader *** this paper, the influence of lightning current and some other factors on surface electric field were analyzed.

关键词： surface electric field transmission lines leader progression model UHVAC

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Air-gap magnetic field distribution and inductance characteristics in a long primary sectional powered variable pole pitch linear induction motor

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Qinghua Daxue Xuebao/Journal of Tsinghua University 2014年第9期54卷 1161-1165and1172页

作者： Mu, Shujun Chai, Jianyun Sun, Xudong Wang, Shanming State Key Lab. of Security Control and Simulation of Power Systems and Large Scale Generation Equipments Department of Electrical Engineering Tsinghua University Beijing100084 China

This study investigated the air-gap magnetic field distribution and inductance characteristics of a long primary sectional powered variable pole pitch linear induction motor (VPPLIM). A one-dimensional analytical model and a 2-D finite element model were used to analyze the air-gap magnetic field distribution in the VPPLIM with harmonic fields for uniformly accelerating the mover with a typical AC supply. The air-gap magnetic field distribution was used to develop analytical expressions for the self-and mutual-inductances of the motor and their characteristics. The analytical expressions are verified by the finite element simulations. ©, 2014, Press of Tsinghua University. All right reserved.

关键词： Inductance

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Progressively Converging Deadbeat control for UPS Inverter

Progressively Converging Deadbeat Control for UPS Inverter

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Annual IEEE Conference on Applied power Electronics Conference and Exposition (APEC)

作者： Y.D. Liu Y. Xing L.P. Huang M. Sakane State Key Laboratory of Security Control & Simulation of Power Systems and Large Scale Generation Equipments Department of Electrical Engineering Tsinghua University Beijing China College of Automation Engineering Nanjing University of Aeronautics and Astronautics Jiangsu China GS Yuasa Power Electronics Limited Osaka Japan

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ANALYSIS OF FATIGUE LIFE LOSS OF DRIVETRAIN OF DOUBLY-FED WIND TURBINES UNDER SHORT-CIRCUIT FAULT OF power GRID

ANALYSIS OF FATIGUE LIFE LOSS OF DRIVETRAIN OF DOUBLY-FED WI...

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International Conference on Renewable power generation

作者： Qiu Shilong Li Hui Gong Lijiao Wang Bin Chai Zhaoseng Wu You Department of Mechanical and Electrical Engineering Shihezi University Shihezi China State Key Laboratory of Power Drivetrain Equipment and System Security Chongqing University Chongqing China State Key Lab of Control and Simulation of Power Systems and Generation Equipments (Department of Electrical Engineering) Tsinghua University Haidian District Beijing China State Key Laboratory of Power Drivetrain Equipment and System Security Chongqing University Chongqing China

ISBN: (数字)9781839531248

ISBN: (纸本)9781839531255

The shafting drivetrain of the doubly fed wind turbine is the part with the highest failure rate. The electromagnetic torque fluctuation caused by the grid fault easily results in the torsional vibration fatigue loss of the shaft. Accordingly, the influences of drivetrain fatigue life loss under different grid faults require investigation. Firstly, the four-mass model of the drivetrain is constructed on the basis of MATlab/Simulink. Secondly, the electromagnetic torque response under short-circuit fault of the grid is obtained via model simulation. Finally, the effects of different types of grid faults on the fatigue life of the drivetrain are analysed through Mlife. Results show that the electromagnetic torque fluctuation load generated by grid fault has no apparent influence on the fatigue life of the drivetrain in the short term, but the cumulative effect of short-term damage will aggravate the fatigue life loss of the drivetrain and increase the failure risk of the component. The electromagnetic torque generated by the three-phase symmetrical short-circuit is the most violent and has the maximum effect on the fatigue life of the drivetrain.

关键词： WIND TURBINE SHORT-CIRCUIT FAULT TORSIONAL VIBRATION FATIGUE LIFE DRIVETRAIN

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Cause Identification of Single-line-to-ground Fault in Distribution System

Cause Identification of Single-line-to-ground Fault in Distr...

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International Conference on power System Technology (powerCON)

作者： Kun Liu Xuan Ren Bin Wang Key Lab for Protective Relaying Real Time Digital Simulation of Guangdong Power Grid Co. Ltd. Power Dispatch Control Center of Guangdong Power Grid Co. Ltd Guangzhou China Key Laboratory of Control and Simulation of Power Systems and Generation Equipment Tsinghua University Beijing China

ISBN: (纸本)9781665407380

Cause identification of single-line-to-ground fault in the distribution system is of great significance to the electric workers for fault isolation and rapid maintenance. The key of fault cause identification is to accurately and quickly distinguish human electric shock faults from non-biological faults. In this paper, human electric shock faults and non-biological faults are modeled and fault characteristics are analyzed. Based on the differences between shape and rotation characteristic of the volt-ampere characteristic curves, a fault cause identification method which can distinguish human electric shock faults from non-biological faults is proposed. simulations show the effectiveness of the method.

关键词： Fault diagnosis Analytical models Shape Electric shock Maintenance engineering power systems

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Nonlinear E-field simulation of HVDC Converter Transformer Busing and Its Structure Optimization With RBF Neural Network and NSGA-II Algorithm

Nonlinear E-field Simulation of HVDC Converter Transformer B...

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IEEE International Conference on power and Energy systems (ICPES)

作者： Yongsheng He Shiling Zhang Zongxiang Lu Pengbo Wang State Grid Chongqing Electric Power Company Chongqing Electric Power Research Institute Chongqing China State Key Lab of Control and Simulation of Power Systems and Generation Equipment Haidian China Dept name of State Key Laboratory of Power Transmission Equipment and System Security and New Technology Chongqing China

Static DC and PR are typical operation conditions of HVDC converter transformer bushing outlet device, moreover, the electrical parameters of RIP, transformer oil and OIP have the nonlinear relationship with E-field stress and temperature. Under the temperature gradient, the electrical parameters will modify the static DC and PR E-field distribution of the composite insulation. In order to simulate static DC and PR electric field of the composite insulation structure, this paper established the full model of the converter transformer outlet. Then, the structure parameters of converter transformer outlet have been optimized using combined RBF neural network and NSGA-II algorithm. Moreover, electric field verification calculation has been carried out under AC and PR conditions. The results show that under uniform temperature condition, E-field strength is larger than that under iso-thermal condition. The overshoot coefficient of the bushing end and barrier reach 65% and 45%, respectively. The study can provide reference for the design of outlet structure of the converter transformer.

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Deep transfer network with joint distribution adaptation: A new intelligent fault diagnosis framework for industry application

arXiv

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arXiv 2018年

作者： Han, Te Liu, Chao Yang, Wenguang Jiang, Dongxiang Department of Energy and Power Engineering Tsinghua University Beijing100084 China State Key Lab of Control and Simulation of Power System and Generation Equipment Tsinghua University Beijing100084 China

In recent years, an increasing popularity of deep learning model for intelligent condition monitoring and diagnosis as well as prognostics used for mechanical systems and structures has been observed. In the previous studies, however, a major assumption accepted by default, is that the training and testing data are taking from same feature distribution. Unfortunately, this assumption is mostly invalid in real application, resulting in a certain lack of applicability for the traditional diagnosis approaches. Inspired by the idea of transfer learning that leverages the knowledge learnt from rich labeled data in source domain to facilitate diagnosing a new but similar target task, a new intelligent fault diagnosis framework, i.e., deep transfer network (DTN), which generalizes deep learning model to domain adaptation scenario, is proposed in this paper. By extending the marginal distribution adaptation (MDA) to joint distribution adaptation (JDA), the proposed framework can exploit the discrimination structures associated with the labeled data in source domain to adapt the conditional distribution of unlabeled target data, and thus guarantee a more accurate distribution matching. Extensive empirical evaluations on three fault datasets validate the applicability and practicability of DTN, while achieving many state-of-the-art transfer results in terms of diverse operating conditions, fault severities and fault types. Copyright © 2018, The Authors. All rights reserved.

关键词： Fault detection

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Transient stability assessment based on 2D combined attribute decision tree

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Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering 2009年第SUPPL. 1期29卷 17-24页

作者： Wang, Kang Sun, Hong-Bin Zhang, Bo-Ming Wu, Wen-Chuan Jiang, Wei-Yong State Key Lab. of Control and Simulation of Power Systems and Generation Equipments Dept. of Electrical Engineering Tsinghua University Haidian District Beijing 100084 China

A method for the power system transient stability assessment based on 2D combined attribute decision tree was proposed. Different from single attribute decision trees, the 2D trees combine two attributes as one automatically to improve its classifying ability in case of multi-dimension and nonlinear border among classes. In the proposed 2D tree, Gini coefficient based 2D combined splitting criterions was adopted and search method for splitting line in an inverse direction was developed. Case study was carried out in one-machine infinite bus system, IEEE 39-bus system and a real provincial system. Results show that, 2D combined attribute decision trees generated by the proposed method are smaller in structure, have the higher accuracy and generalization ability than that generated by the single attribute decision trees. Meanwhile, some important relationship between physical variables in power systems can be mined by the proposed method. Advantages mentioned above make that the proposed method is potential for real-life power system applications. © 2009 Chin. Soc. for Elec. Eng.

关键词： Decision trees

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Interval economic dispatch model with uncertain wind power injection and spatial branch and bound method

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Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering 2014年第22期34卷 3707-3714页

作者： Ding, Tao Guo, Qinglai Bo, Rui Zhang, Liping Sun, Hongbin Wu, Wenchuan Zhang, Boming State Key Lab of Control and Simulation of Power Systems and Generation Equipment Department of Electrical Engineering Tsinghua University Haidian District Beijing100084 China Midwest ISO St. Pau55108 United States Department of Mathematical Science Tsinghua University Haidian District Beijing100084 China

power injection becomes stochastic due to large-scale wind power integration into power grid, which greatly challenges the traditional power grid. If the uncertainty is modelled using the interval number, the solution of economic dispatch model can also be represented as an interval number. To achieve the precise upper and lower bound, two deterministic programming models were deduced: the optimistic solution can be obtained by an optimistic model using linear programming, whereas the pessimistic solution achieved by a pessimistic model is an NP-hard problem, which can be transformed into a bilinear programming by duality theory. Then a linear relaxation technology, spatial branch and bound method were used to obtain the global pessimistic solution. Therefore, the interval bound information can provide the operator with institutive bound information for the future security assessment. Finally, a test system with 15 generators and 300 nodes was studied at different time scales. The result, compared with interior point method and enumeration, shows the effectiveness of proposed method. © 2014 Chinese Society for Electrical Engineering.

关键词： Wind power

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Gas generation Characteristics of Transformer oil under Combined AC-DC Voltages in the Process of Arcing

Gas Generation Characteristics of Transformer oil under Comb...

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Annual Report Conference on Electrical Insulation and Dielectric Phenomena

作者： Y.X. Zhou Y.C. Sha X.X. Jiang Q.H. Sun Y.S. Wang J.H. Tian State Key Lab of Control and Simulation of Power Systems and Generation Equipments Department of Electrical Engineering Tsinghua University Haidian District Beijing China

ISBN: (纸本)9781457709852

As an important equipment, convertor transformer plays a crucial role in ultra high voltage direct current (UHVDC). How to improve the safety running level of convertor transformers is a key problem to be solved imminently. Compared with AC power transformers, the valve side windings of convertor transformers will endure combined AC-DC voltage. In these conditions, the gas generation characteristics in oil for convertor transformers will be more complicated. In this paper, according to the operational principle of convertor transformers, the ratios between AC and DC voltage on valve side windings in the star connection and triangular connection were 77.1% and 83.7% respectively. Based on the above results, 65 kV peak voltages in 5 different AC and DC voltage forms were applied to the needle-plate electrode model for 2 hours. The discharge current and voltage waveforms were recorded and the arc current pulses had a short lasting time about 1.2 ms. Then the mean discharge energy was calculated at 0.1 to 0.3 J. At the same time, the gas generation characteristics under combined AC-DC voltage were obtained by using the gas chromatographic analysis method. The variations of amounts and generation rates of characteristic gases were measured with time during 2 hours, which provided fault judgment criterions and experimental experience. The experimental results showed that the amounts and generation rates of H2, C2H2 and total hydrocarbon under the pure DC voltage or combined AC-DC voltage were more than those under the pure AC voltage. It might illustrate the fact that effects of different voltage forms would lead to different gas generation characteristics could not be ignored.

关键词： Combined AC-DC voltage Needle-plate electrode model Gas generation Characteristics

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