检索结果-内蒙古大学图书馆

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

作者： Nan Li Jiancheng Zhang Yun Zhong Key Laboratory of Power System Protection and Dynamic Security Monitoring and Control under Ministry of Education North China Electric Power University Baoding Hebei China

A control scheme is described to charge series-connected super capacitors for photovoltaic generation systems. Based on the features of the super capacitors charge, the control scheme consists of three modes, i.e., the constant current charge mode, the constant power charge mode, and the constant voltage charge mode. The shift of three modes can be realized by controlling the duty of IGBT in the Boost-Buck converter system. Meanwhile, the high voltage, which is more suitable for application, can be obtained. Compared with the normal charge method with series-connected current-limiting resistance and the charge method with the constant current charge mode and the constant voltage charge mode, the proposed charging control scheme can shorten the charging time and improve the usage of the electric power generated from the PV arrays. The advantage described above is verified by simulations.

关键词： control systems Capacitors Energy storage Photovoltaic systems Solar power generation power generation Supercapacitors Voltage control Pulsed power supplies Uninterruptible power systems

来源：评论

学校读者我要写书评

暂无评论

Study on assessment model of event-type power disturbances

Study on assessment model of event-type power disturbances

引用

IEEE Asia-Pacific Conference on Circuits and systems

作者： Xiangning Xiao Shun Tao Key Laboratory of Power System Protection and Dynamic Security Monitoring and Control North China Electric Power University Changping District Beijing P.R.China

This paper discussed the characteristics of power disturbances, and then proposed new classifying method. Disturbances are classified into two main categories, ldquocontinuous typerdquo and ldquoevent typerdquo. Continuous type disturbances typically include voltage deviation, power frequency deviation, unbalance, flicker and harmonics. Event type disturbances (ETD) include voltage sags (including short duration interruptions), outages, and transients. Based on the classification of power disturbances and traditional distribution reliability indices (SAIDI, CAIDI, SAIFI, CAIFI, and ASAI), Voltage sag indices coordinate interruption events indices were proposed: 1) SASDI and CASDI, 2) SASFI and CASFI. The comprehensive index ASAI*, a corrected ASAI, was defined based on SAIDI and SASDI coordinate of the economic losses of customers impacted by event type disturbances. The assessment model of ETD was proposed. The model represents the defined indices, the calculating procedure, the phase aggregation, and the time aggregation, which are four basic factors to rightly assessment power quality. A case study was used to testify the comprehensive method was reasonable and feasible.

关键词： power quality Frequency Voltage fluctuations power system transients monitoring power system reliability power system harmonics power system modeling Laboratories power system protection

来源：评论

学校读者我要写书评

暂无评论

Lessening zero sequence effects in dynamic voltage restorers

Lessening zero sequence effects in dynamic voltage restorers

引用

IEEE Asia-Pacific Conference on Circuits and systems

作者： Zhang zhi Yin zhongdong Zhang changyin Shang weidong Huang zhonghua Key Laboratory of Power System Protection and Dynamic Security Monitoring and Control North China Electric Power University Beijing China Kaifeng Power Supply Corporation Kaifeng China

This paper puts forward an analysis of the effects of zero sequence components on power devices in particularly on the dynamic voltage restorer (DVR) and gives simulation results. It is shown that four-wire DVR do better then the traditional three-wire DVR, unbalance voltage and zero sequence components can be lessened by four-wire DVR effectively, because it provides zero sequence current circuit. However, the interaction between DC-side and AC-side in this topology leads to an unbalance in the DC-link capacitor voltages and it causes zero sequence resonance especially when the DVR is under open loop control. But the closed loop control can provide additional damping to mitigate possible harmonic resonance. In this study, the DVR system is simulated by using PSCAD software. Simulation results are presented to verify the theoretical analysis.

关键词： power quality Voltage fluctuations power system restoration power system dynamics power system protection Analytical models Resonance Open loop systems power system harmonics PSCAD

来源：评论

学校读者我要写书评

暂无评论

Using bacterial chemotaxis method for reactive power optimization

Using bacterial chemotaxis method for reactive power optimiz...

引用

Transmission and Distribution Exposition Conference: 2008 IEEE PES powering Toward the Future, PIMS 2008

作者： Huang, Wei Zhang, Cong Yang, Jingyan Zhang, Jianhua Liu, Zifa Wei, Zhilian Pan, Dongli Key Laboratory of Power System Protection and Dynamic Security Monitoring and Control North China Electric Power University Ministry of Education Dewai Zhuxinzhuang Beijing 102206 China

ISBN: (纸本)9781424419036

Reactive power optimization is one of the key problems in power system which makes the voltage quality and stability improved and the loss of the power system reduced. This paper briefly analyzes the limitation of some reactive power optimization methods for power system and then a more effective method based on bacterial colony chemotaxis is proposed to solve this problem which is a discrete, many variables and nonlinear programming one. We adjust the bacterial colony chemotaxis model to fit the reactive power optimization calculation and make an improvement of it to enhance its convergence speed and search efficiency. This method applies to the IEEE-30, IEEE-57, IEEE-118 bus system, and the result proves the practicability and validity of this method. Compared with SGA and CPSO optimal method, the simplicity and robustness of the process of bacterial colony chemotaxis suggest a research direction which is worth to move on. ©2008 IEEE.

关键词： Nonlinear programming

来源：评论

学校读者我要写书评

暂无评论

A VSC-HVDC Fuzzy controller for Improving the Stability of AC/DC power system

A VSC-HVDC Fuzzy Controller for Improving the Stability of A...

引用

11th International Conference on Electrical Machines and systems(第11届国际电机与系统会议)

作者： Sheng Li Jianhua Zhang Jingfu Shang Ziping WU Mingxia Zhou Key Laboratory of Power System Protection and Dynamic Security Monitoring and Control under Ministry of Education (North China Electric Power University) Changping District Beijing 102206 China

This paper puts forward an auxiliary fuzzy logic controller for the Voltage Source Converter based HVDC transmission system, VSC-HVDC, to improve the stability of the AC/ DC system by damping the oscillation effectively after disturbance. The fast control capability of the VSC-HVDC and the process of area mode oscillations are analyzed. No detailed model of the system is required for the design of the proposed control scheme. The controller judges the operation states and the control effect and accordingly adjusts its active power order in an adaptive way by using fuzzy rules, so as to damp out the area mode 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： VSC-HVDC fuzzy logic control tie-line oscillation

来源：评论

学校读者我要写书评

暂无评论

Research on the influence of TCSC to EHV transmission line protection

Research on the influence of TCSC to EHV transmission line p...

引用

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

作者： Qing Liu Zengping Wang Yan Xu Key Laboratory of Power System Protection and Dynamic Security Monitoring and Control under Ministry of Education North China Electric Power University Baoding City Heibei Province China

Thyristor controlled series capacitor (TCSC) used in power transmission line can increase the transportability and the stability of system, and decrease the system loss significantly. At the same time, TCSC brings many serious problems to transmission lines fault location and protective relaying. This paper analyzes the influence of TCSC to EHV transmission line protection, especially to the high-frequency directional protection. It can be obtained from the analyzing that the addition of TCSC to EHV transmission line would make the high-frequency directional protection unwanted operation or failure to operate. In order to solute the problems TCSC caused, this paper presents a novel transient protection scheme based on wavelet transform (WT). The simulation tests have proved that the analyzing and solution of the appearance of TCSC in EHV transmission line are correct.

关键词： power capacitors Thyristors power system protection power transmission lines control systems Stability Propagation losses Fault location Protective relaying Failure analysis

来源：评论

学校读者我要写书评

暂无评论

Mathematical model of new bi-directional DC-AC-DC converter for supercapacitor energy storage system in photovoltaic generation

Mathematical model of new bi-directional DC-AC-DC converter ...

引用

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

作者： Yun Zhong Jiancheng Zhang Gengyin Li Xindi Yuan Key Laboratory of Power System Protection and Dynamic Security Monitoring and Controlunder Ministry of Education North China Electric Power University Baoding Hebei China

Energy storage system is an all-important part in photovoltaic. A new bidirectional DC-AC-DC converter for supercapacitor energy storage system in photovoltaic generation is put forward. In the beginning, some experiments on super capacitor have been performed, which shows super capacitor has good performance in quick charge and discharge. And mathematical model of the dual full-bridge bidirectional DC-AC-DC converter circuits with a transformer and its simplified model are derived. In the end, A phase current in the transformer primary side (ia) can be investigated with mathematical calculation simulation and detailed circuit simulation. The comparative result shows the mathematical model rationality. Through deduction, unified model of SESS also can be gotten.

关键词： Mathematical model Bidirectional control Supercapacitors Energy storage Photovoltaic systems Solar power generation Capacitors power transformer insulation Circuit simulation power generation

来源：评论

学校读者我要写书评

暂无评论

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

引用

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

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

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

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：