检索结果-内蒙古大学图书馆

Adaptive ant colony algorithm based on cloud model and its application in power distribution network planning

Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering 2008年第SUPPL.期28卷 52-57页

作者： Xie, Qing Li, Yan-Qing Peng, Peng Wang, Ling Liu, Wen-Cai Lu, Fang-Cheng Key Laboratory of Power System Protection and Dynamic Security Monitoring and Control Min. of Edu. North China Electric Power University Baoding 071003 China Guangdong Power Grid Corporation Guangzhou 510600 China Beijing National Railway Research and Design Institute of Signal and Communication Fengtai District Beijing 100073 China

The distribution network structure planning can enhance the reliability and the efficiency of the grid. An adaptive ant colony algorithm based on cloud model was proposed and applied in distribution network structure planning in this paper. In view of the main disadvantage of being inclined to local convergence and slow convergence speed of traditional ant colony algorithm, the parameter ρ and Q were qualitatively controlled and dynamically selected in this paper by employing the uncertain qualitative association rule inference based on cloud model, which is one indefinite model for transformation between qualitative and quantitative knowledge. The algorithm overcomes the shortcoming of traditional ant colony algorithm, and the simulation results of power distribution network planning demonstrated the efficiency of the algorithm.

关键词： Efficiency

来源：评论

学校读者我要写书评

暂无评论

dynamic secondary arc analysis and simulation research under different line model

Dynamic secondary arc analysis and simulation research under...

引用

IEEE Asia-Pacific Conference on Circuits and systems

作者： Lixia Zhou Zhongdong Yin Xiangning Xiao Yueting Tan Key Laboratory of Power System Protection and Dynamic Security Monitoring and Control under Ministry of Education North China Electric Power University Beijing China Langfang Power Supply Corporation (North China Power Grid) Langfang China

In the extra high voltage (EHV) transmission system, the transient single-phase to ground faults are the most frequent to occur. Even after the opening of breakers in the two sides of the fault line, an induced current still exists in the arc because of the electrostatic and the electromagnetic coupling from the other two sound phases. Along with the enhancement of the voltage grade, the influence of the secondary arc becomes more and more, and may probably lead to the failure of the reclosing if the secondary arc is not extinguished promptly. In this paper, the dynamic secondary arc model (including recovery voltage and the secondary arc current) in single-phase asymmetric breaking is established based on the distribution parameters of EHV long-line. The method of twice-mode transformation is adopted to calculate the steady-state value of the secondary arc current and recovery voltage. Furthermore, the affects of different overhead line models on the secondary arc current are also analyzed through the real time digital simulation.

关键词： Analytical models Voltage power system transients Electromagnetic transients Electrostatics Electromagnetic coupling power system dynamics Steady-state Digital simulation Stability

来源：评论

学校读者我要写书评

暂无评论

Study of reactive power optimization based on Artificial Immune Ant Colony Algorithm

Study of reactive power optimization based on Artificial Imm...

引用

International Conference on Electric Utility Deregulation and Restructuring and power Technologies (DRPT)

作者： Siqing Sheng Jing Li Key Laboratory of Power System Protection and Dynamic Security Monitoring and Control under Ministry of Education North China Electric Power University Baoding Hebei China Student power system and itns automation North China Electric Power University Baoding Hebei China

This paper presents an algorithm for optimizing reactive power using Artificial Immune Ant Colony Algorithm. This hybrid algorithm uses artificial immune algorithm (AIA) to give pheromone to distribute and makes use of Ant Colony Algorithm (ACA) to give the optimal solution. The ACA has been improved. The improved ACA uses the best and worst ant to update the pheromone trails and pseudorandom proportional rule. Local pheromone update mechanism, pheromone limitation and adaptive pheromone decay coefficient are increased. The objective function of the proposed algorithm is to minimize the system active power loss. This algorithm has been applied to practical IEEE 30-bus system and shows better results and convergence rate as compared to other optimal methods.

关键词： Reactive power Ant colony optimization power system security power system stability Propagation losses Constraint optimization Feedback power system protection power system dynamics Mathematical model

来源：评论

学校读者我要写书评

暂无评论

Study on power factor through the similarity of waveform

Study on power factor through the similarity of waveform

引用

IEEE Conference on Industrial Electronics and Applications (ICIEA)

作者： L.X. Zhou Z.D. Yin X.N. Xiao Z.Q. Wang L. Zheng Key Laboratory of Power System Protection and Dynamic Security Monitoring and Control under Ministry of Education North China Electric Power University Beijing China North China Power Grid Xingtai Power Supply Corporation Xingtai China

With the rapid development of electric electronic technology, non-linear loads, large capacity converters, etc. increase mostly, which brings about the serious problems such as harmonics. Thus, the traditional power theory based on the average is unable to meet with the practical require. In this paper, the power definition in the sinusoidal and non-sinusoidal circuit is discussed and the waveform similarity between voltage and current is analyzed due to the criterion of minimum mean square deviation. Furthermore, the relationships among the waveform similarity factor, displacement power factor and real power factor are also discussed. The results show that power components are well analyzed in use of waveform similarity under the conditions of non-sinusoidal. At the same time, waveform similarity provides a simple but effective method for the calculation of power factor.

关键词：

来源：评论

学校读者我要写书评

暂无评论

A VSC-HVDC fuzzy controller to damp oscillation of AC/DC power system

A VSC-HVDC fuzzy controller to damp oscillation of AC/DC pow...

引用

IEEE International Conference on Sustainable Energy Technologies, ICSET

作者： Chunye Li Sheng Li Fuchun Han Jingfu Shang Ermin Qiao College of Electrical and Power Engineering Taiyuan University of Technology Taiyuan China Key Laboratory of Power System Protection and Dynamic Security Monitoring and Control Ministry of Education Beijing China China Electrical Power Research Institute China

The fast control capability of the VSC-HVDC and the process of area mode oscillations are analyzed. An auxiliary fuzzy logic controller designed in Matlab for the voltage source converter based HVDC transmission system, VSC-HVDC, to improve the stability of the AC/DC system is designed to enhance stability by increasing the deceleration energy of oscillation. Simulation results on the IEEE 4-generator AC/DC power systems have shown that the controller can enhance the dynamic stability of interconnected power systems effectively and is robust to the variation of system operating conditions and oscillation modes.

关键词： Fuzzy control Fuzzy systems Control systems power systems power system stability Converters power conversion power system simulation power system interconnection power system dynamics

来源：评论

学校读者我要写书评

暂无评论

Experimental study on relationships between partial discharge signals and apparent discharge magnitude in XLPE cable

Experimental study on relationships between partial discharg...

引用

International Conference on Condition Monitoring and Diagnosis, CMD

作者： Wei Wang Xu Cheng Chong Liu Fei Zong Xueliang Shen Beijing Key Laboratory of High Voltage & EMC Key Laboratory of Power System Protection and Dynamic Security Monitoring and Control Ministry of Education North China Electric Power University Beijing China Beijing Electric Test and Research Institute Beijing China

ISBN: (纸本)9781424416219

Based on the experiment carried out in the lab on several cables in which there are some typical PD models, the relationship between the single acoustic signal generated by the partial discharge and the apparent discharge magnitude in a line frequency cycle are researched. Further more, through the detection system which is combined of the VHF PD detection method and the acoustic emission detection method, the expressions of the relationship between the voltage value, which is gotten directly from the detection system and the apparent discharge magnitude are gotten by the curve fitting method. At the same time, the method of locating the defect manually with the acoustic sensor is introduced simply in the paper.

关键词： Partial discharges Acoustic signal detection Acoustic emission Cables Signal generators Frequency Voltage Fault location Curve fitting Acoustic sensors

来源：评论

学校读者我要写书评

暂无评论

Detection method of partial discharge in XLPE Cable accessories based on the method of VHF combined with acoustic emission

Detection method of partial discharge in XLPE Cable accessor...

引用

International Symposium on Electrical Insulating Materials

ISBN: (纸本)9784886860057

Based on the experiment carried out in the lab on several cable accessories in which there are some typical PD models(In this paper, they are the models of protrusion discharge and floating discharge), the method of VHF Combined with acoustic emission (AE) for detecting PD in the XLPE cable accessories was introduced. The time domain characters of the AE and VHF signals are researched and compared in order to distinguish the PD signal from the disturbance. Two kinds PD spectrum of Qmax-phi and N-phi were analyzed and contrasted between the VHF and acoustic emission PD signals, which are protrusion discharge and floating discharge. The way to locate the PD point was also introduced. The results of the research had proved that the reliability of the PD detection is improved using the combined method.

关键词： Partial discharges Acoustic emission power cables Discharges Joints Fault location Acoustics

来源：评论

学校读者我要写书评

暂无评论

Research on Failure Risk Assessment and Maintenance Tactics of Transformer based on the Extension Engineering Method and IAHP

Research on Failure Risk Assessment and Maintenance Tactics ...

引用

International Conference on High Voltage Engineering and Application, ICHVE

作者： Qing Xie Yun Li Yunpeng Liu Yanqing Li Fangcheng Lv Key Laboratory of Power System Protection and Dynamic Security Monitoring and Control Ministry of Education North China Electric Power University Baoding Hebei China Wuhan High-Voltage Research Institute Baoding Hebei China

There are many failure modes of transformer, and their probability and failure severity differ from each other. Based on the statistic data and experts advice, the probability of all failure modes are calculated, and divided into 5 grades. Meanwhile, IAHP was applied to calculate the weight of the transformer failure information, and Extension evaluation method was employed to create the frame work of the severities of failure modes qualitatively and divided them into 5 grades as well. Then, risk matrix is adopted to describe risk grades of failure modes, and power transformer risk maintenance strategies are obtained.

关键词： Risk management power transformers Failure analysis Risk analysis power system security Maintenance power system reliability power engineering and energy Probability protection

来源：评论

学校读者我要写书评

暂无评论

Neural Network Approaches to Unimodal Surjective Map Chaotic system Forecasting

Neural Network Approaches to Unimodal Surjective Map Chaotic...

引用

International Symposium on Intelligent Information Technology Application, IITA

作者： Yagang Zhang Po Zhang Xiaozhe Wang Zengping Wang Key Laboratory of Power System Protection and Dynamic Security Monitoring and Control under Ministry of Education North China Electric Power University Baoding China Center for Nonlinear Complex Systems Yunnan University Kunming China

The forecasting using neural networks in unimodal surjective map chaotic dynamic system will be studied carefully in this paper. And most of the forecasting precision has exceeded 90%. Because of the intrinsic property of chaos, the forecasting precision will decrease as the length of symbolic sequence is increasing. But in this place we have found a generating rule that may realize chaotic synchronization at least in short and medium term, and we can analysis and forecast in this way. Nonlinear dynamics maintain manifold links with biologic information system. We also hope to offer an effective prediction method to study certain properties of DNA base sequences, 20 amino acids symbolic sequences of proteid structure, and the time series that can be symbolic in finance market et al.

关键词： Neural networks Chaos Sequences Economic forecasting Nonlinear dynamical systems Information systems Prediction methods DNA Amino acids Finance

来源：评论

学校读者我要写书评

暂无评论

A power price forecasting method based on nonparametric GARCH model

A power price forecasting method based on nonparametric GARC...

引用

3rd International Conference on Deregulation and Restructuring and power Technologies, DRPT 2008

作者： Hong, Li Hao, Xiong Weiguo, Li Yi, Sun Guoyi, Xu IEEE North China Electric Power University Wuhan University Beijing Institute North China Electrical Power University Electrical Engineering School North China Electric Power University Beijing China Key Laboratory of Power System Protection and Dynamic Security Monitoring and Control

ISBN: (纸本)9787900714138

Based on nonparametric conditional heteroscedasticity estimation theory, an improved power price forecasting method is proposed in this paper. In this method, according to the practical power price curve, conditional variance function is built and the model is determined by nonparametric estimation method. Besides, in the nonparametric estimation process, the iterative estimation algorithm is introduced to deal with the problem where conditional standard deviation is unpredictable. And the estimation credence of conditional variance function is improved by continually modifying the estimation value of conditional standard deviation as input variance. On the research of day-ahead time series fluctuation characteristics of power price in California in 2000, the time series of Humb node is modeled and forecasted. And the test results show that the model proposed in this paper can better reflect time series volatility clustering characteristics of power price, and it can improve forecasting effect of peak power price by using nonparametric estimation theory. © 2008 DRPT.

关键词： Time series

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：