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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

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dynamic secondary arc analysis and simulation research under different line model

Dynamic secondary arc analysis and simulation research under...

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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

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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...

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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

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

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

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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

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Study on power factor through the similarity of waveform

Study on power factor through the similarity of waveform

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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：

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

Experimental study on relationships between partial discharg...

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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

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A novel approach to eliminate zero-sequence harmonics current

A novel approach to eliminate zero-sequence harmonics curren...

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IEEE Asia-Pacific Conference on Circuits and systems

作者： Qipeng Song Zhongdong Yin Chengxi Dai Changyin Zhang Weidong Shang Zhonghua Huang Key Laboratory of Power System Protection and Dynamic Monitoring and Control Ministry of Education University Beijing China Kaifeng Power Supply Corporation Kaifeng China Kaifeng Power Supply Corporation The state grid corporation of China Kaifeng

Zero-sequence harmonics caused by nonlinear loads usually result in high voltage distortion levels throughout the facility, neutral conductor overloading, motor heating, transformer heating, increased losses, and excessive harmonic injection onto the utility supply system. This paper presents a novel method to eliminate zero-sequence harmonics by using Zero-sequence Resister Block (ZRB) and Zig-Zag transformer. Zig-Zag transformer is a special connection of three-phase transformerpsilas windings. The ZRB is also a special connected transformer, whose three windings are wounded in the same core. The ZRB has zero reactance for positive and negative-sequence components but giving three times of self-reactance for zero-sequence reactance. In this paper, an analysis is carried out; simulations and laboratory tests are used to evaluate the performance of the Zig-Zag transformer and ZRB under various system conditions. The simulation and laboratory test results indicate that the combination of ZRB and Zig-Zag transformer as filter is a better and effective way to attenuate the neutral current, which also provides an innovational way to improve power quality.

关键词： power harmonic filters Heating Laboratories Harmonic distortion Conductors Transformer cores Performance analysis Analytical models system testing power quality

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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...

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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

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The characteristic of silicon rubber insulators contaminated with concrete

The characteristic of silicon rubber insulators contaminated...

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International Conference on Condition monitoring and Diagnosis, CMD

作者： Fochi Wang Chengrong Li Yongjiang Bi Linjie Zhao Beijing Key Laboratory of High Voltage & EMC Key Laboratory of Power System Protection and Monitoring and Control Ministry of Education North China Electric Power University China

ISBN: (纸本)9781424416219

Concrete-polluted silicone rubber (SIR) insulators are common nature-polluted insulators. A type of concrete-polluted SIR insulators with different content of concrete was evaluated. The flashover voltage of concrete-polluted insulators was tested after placing in artificial climatic chamber for 6 hours with ultrasonic fog device continual working. The incepted discharge area always occurs at the umbrella edge and the connected area of the hardware fittings and core rod for light concrete-polluted SIR insulators. However, the incepted discharge area always occurs at connected place of core rod and hardware fitting for heavy concrete-polluted one. The flashover voltage decreases with the increase of concrete content by a power function and the influence factor of the concrete deposit density b is 0.194. Even though after a long time transfer, the hydrophobicity of heavy concrete-polluted SIR insulators also decrease with the increase of concrete-polluted content.

关键词： Silicon Rubber Concrete Pollution Insulator testing Flashover Dielectrics and electrical insulation Voltage Building materials power transformer insulation

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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 ...

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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

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