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A new compensation current.real-time computing method for power active filter based on double linear construction algorithm

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Science China(Technological Sciences) 2006年第4期49卷 485-512页

作者： LI Zicheng SUN Yukun College of Electrical and Information Engineering of Jiangsu University Zhenjiang 212013 China College of Electrical and Information Engineering of Jiangsu University Zhenjiang 212013 China

Considering the detection principle that “when load current.is periodic current. the integral in a cycle for absolute value of load current.subtracting fundamental active current.is the least”, harmonic current.real-time detection methods for power active filter are proposed based on direct computation, simple iterative algorithm and optimal iterative algorithm. According to the direct computation method, the amplitude of the fundamental active current.can be accurately calculated when load current.is placed in stable state. The simple iterative algorithm and the optimal iterative algorithm provide an idea about judging the state of load current. On the basis of the direct computation method, the simple itera- tive algorithm, the optimal iterative algorithm and precise definition of the basic concepts such as the true amplitude of the fundamental active current.when load current.is placed in varying state, etc., the double linear construction idea is proposed in which the amplitude of the fundamental active current.at the moment of the sample is accurately calculated by using the first linear construction and the condition which disposes the next sample is created by using the second linear construction. On the basis of the double linear con- struction idea, a harmonic current.real-time detection method for power active filter is proposed based on the double linear construction algorithm. This method has the char- acteristics of small computing quantity, fine real-time performance, being capable of ac- curately calculating the amplitude of the fundamental active current.and so on.

关键词： power active filter, harmonic current. active current. reactive current.

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A NEW TYPE OF current.CARRYING ALFVEN VORTEX

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Chinese Science Bulletin 1992年第10期37卷 810-814页

作者：陈银华朱栋培 Department of Modern Physics University of Science and Technology of China Hefei 230026 PRC

The low-frequency mode in plasma is very important for the study of plasma transport and confinement. Many authors have widely investigated the various nonlinear low-frequency modes in magnetized plasma, but the investigations were limited to the situation of static equilibrium plasma. This note studies the shear Alfven wave in current.carrying plasma where the electron component moves slowly with respect to the ion component. A new solution of dipole vortex has been obtained, the wave characteristic

关键词： vortex Alfven wave current. carrying plasma

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MICROSTRUCTURE AND CRITICAL current.OF ORIENTATED YBaCuO THIN FILMS

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Chinese Science Bulletin 1989年第5期34卷 370-374页

作者：王会生赵柏儒陆勇张鹰子袁彩文史引焕赵玉英高炬李林 Institute of Physics Academia Sinica Beijing

Ⅰ. INTRODUCTIONThere are many reports on the study of the high T_c oxide superconducting thin films. Now the main attention is focussed on how to prepare single-phase thin films and raise their critical current.density J_c, in order to realize the usage of superconducting electronic devices operating at liquid nitrogen temperature in

关键词： superconducting structure morphology critical current.

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Possible triggering of solar activity to big earthquakes (Ms ≥ 8) in faults with near west-east strike in China

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Science China(Physics,Mechanics & Astronomy) 2004年第2期47卷 173-181页

作者： HAN Yanben1, GUO Zengjian1,2, WU Jinbing1,2 & MA Lihua1 1. National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China 2. Earthquake Research Institute of Lanzhou, CSB, Lanzhou 73000, China Correspondence should be addressed to Han Yanben (email: hyb@***) National Astronomical Observatories Chinese Academy of Sciences Beijing China Earthquake Research Institute of Lanzhou CSB Lanzhou China

This paper studies the relationship between solar activity and big earthquakes (Ms≥8) that occurred in China and western Mongolia. It is discovered that the occurrence dates of most of the big earthquakes in and near faults with west-east strike are close to the maximum years of sunspot numbers, whereas dates of some big earthquakes which are not in such faults are not close to the maximum years. We consider that it is possibly because of the appearance of many magnetic storms in the maximum years of solar activity. The magnetic storms result in anomalies of geomagnetic field and then produce eddy current.in the faults gestating earthquake with near west-east strike. Perhaps the gestated big earthquakes occur easily since the eddy current.heats the rocks in the faults and therefore decreases the shear resistant intensity and the static friction limit of the rocks .

关键词： earthquake, solar activity, magnetic storm, eddy current.

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Characteristics of InGaN multiple quantum well blue-violet laser diodes

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Science China(Technological Sciences) 2006年第6期49卷 727-732页

作者： LI Deyao1, ZHANG Shuming1, WANG Jianfeng1, CHEN Jun1, CHEN Lianghui2, CHONG Ming2, ZHU Jianjun1, ZHAO Degang1, LIU Zongshun1, YANG Hui1 & LIANG Junwu1 1. State Key Laboratory of Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China 2. Nano-Optoelectronics Laboratory, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China State Key Laboratory of Integrated Optoelectronics Institute of Semiconductors Chinese Academy of Sciences Beijing China Nano-Optoelectronics Laboratory Institute of Semiconductors Chinese Academy of Sciences Beijing China

Studies on InGaN multiple quantum well blue-violet laser diodes have been reported. Laser structures with long-period multiple quantum wells were grown by metal-organic chemical vapor deposition. Triple-axis X-ray diffraction (TAXRD) measurements show that the multiple quantum wells were high quality. Ridge waveguide laser diodes were fabricated with cleaved facet mirrors. The laser diodes lase at room temperature under a pulsed current. A threshold current.density of 3.3 kA/cm[2]; a characteristic temperature T 0 of 145 K were observed for the laser diode.

关键词： metalorganic chemical vapor deposition (MOCVD), GaN-based laser diodes, multiple quantum well, ridge waveguide, threshold current.

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Distribution of chlorophyll-a off the Changjiang River and its dynamic cause interpretation

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Science China Earth Sciences 2005年第7期48卷 950-956页

作者： ZHU Jianrong State Key Laboratory of Estuarine and Coastal Research East China Normal University Shanghai 200062 China

An interdisciplinary comprehensive survey was conducted in August 2000 with the modern measurement instruments off the Changjiang River. The analysis of the observation data shows that there exist two sources of phytoplankton blooms off the Changjiang River. The one with wider spatial extent and stronger intensity appears in the surface plume due to photosyn- thesis produced by the eutrophication brought by a huge amount of nutrient load via the Chang- jiang River and well light penetration because of lower turbidity seawater. Photosynthesis pro- duces chlorophyll-a (Chl-a), meanwhile releases oxygen and absorbs carbon dioxide, so the high Chl-a concentration distribution corresponds to the distribution of high dissolved oxygen and pH. The other with smaller spatial extent and weaker intensity exists in the thermocline in the Taiwan Warm current.(TWC), but the high Chl-a concentration does not correspond to the high dissolved oxygen and pH, which may be a result of long distance advection by the TWC. The eutrophica- tion associated with the huge amount of nutrient flowing into the sea via the Changjiang River is the main cause of the red tide bloom in the area off the Changjiang River, the red tide that oc- curred along the Fujian and Zhejiang coast can influence the area off the Changjiang River pos- sibly via the TWC. The distributions of current.simulated by a three-dimension numerical model support the above conclusion.

关键词： area off the Changjiang River field survey red tide eutrophication Taiwan Warm current.

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NUMERICAL SIMULATION OF THE MINDANAO EDDY AND TROPICAL current. OF PACIFIC OCEAN

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Chinese Journal of Oceanology and Limnology 1992年第3期10卷 258-267页

作者：李荣凤曾庆存季仲贞 LASG Institute of Atmospheric Physics Academia Sinica Beijing 100080

Results of numerical simulation of current. in the western North Tropical Pacific Ocean by using a barotropic primitive equation model with fine horizontal resolution agreed well with observations and showed that the Mindanao Cyclonic Eddy located north of the equator and east of Mindanao Island exists during most of the year with monthly (and large seasonal) variations in scope . strength and central location . In June , an anticyclonic eddy occurs northeast of Halmahera Island, strengthens to maximum in August , exists until October and then disappears . The observed large-scale circulation systems such as the North Equatorial current.. the Mindanao current.and the North Equatorial Countercurrent.are all very well reproduced in the simulations.

关键词： numerical simulation North Equatorial current Mindanao current. North Equatorial Countercurrent Mindanao Eddy Halmahera Eddy

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Alternating current.Heating Technique of Hollow Rod

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China Oil & Gas 1995年第4期2卷 42-44页

作者： Na Weisheng and Shi Tonghao(Survey & Design Institute, Liaohe Oilfield) Survey & Design Institute Liaohe Oil field

ＡｌｔｅｒｎａｔｉｎｇＣｕｒｒｅｎｔＨｅａｔｉｎｇＴｅｃｈｎｉｑｕｅｏｆＨｏｌｌｏｗＲｏｄ￥ＮａＷｅｉｓｈｅｎｇａｎｄＳｈｉＴｏｎｇｈａｏ（Ｓｕｒｖｅｙ＆ＤｅｓｉｇｎＩｎｓｔｉｔｕｔｅ，ＬｉａｏｈｅＯｉｌｆｉｅｌｄ）... 详细信息

ＡｌｔｅｒｎａｔｉｎｇＣｕｒｒｅｎｔＨｅａｔｉｎｇＴｅｃｈｎｉｑｕｅｏｆＨｏｌｌｏｗＲｏｄ￥ＮａＷｅｉｓｈｅｎｇａｎｄＳｈｉＴｏｎｇｈａｏ（Ｓｕｒｖｅｙ＆ＤｅｓｉｇｎＩｎｓｔｉｔｕｔｅ，ＬｉａｏｈｅＯｉｌｆｉｅｌｄ）Ｋｅｙｗｏｒｄｓ：Ｃｒｕｄｅｏｉｌ...

关键词： Crude oil. Well bore. Heating. Alternating current. Rod pump

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Implementation of Dynamic Line Rating in a Sub-Transmission System for Wind Power Integration

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Smart Grid and Renewable Energy 2015年第8期6卷 233-249页

作者： Saifal Talpur Carl Johan Wallnerstrom Patrik Hilber Christer Flood School of Electrical Engineering KTH Royal Institute of Technology Fortum Distribution AB Stockholm Sweden

Based on conventional static line rating method, the actual current.carrying capability of overhead conductors cannot be judged. Due to continuous increment in electricity demand and the difficulties associated with new line constructions, the overhead lines are therefore required to be rated based on a method that should establish their real-time capability in terms of electricity transmission. The method used to determine the real-time ampacity of overhead conductors not only can enhance their transmission capacity but can also help in allowing excessive renewable generation in the electricity network. In this research work, the issues related to analyzing an impact of wind power on periodical loading of overhead line as well as finding its static and dynamic ampacities with line current.are investigated in detail. Moreover, the investigation related to finding a suitable location for the construction of a 60 MW wind farm is taken on board. Thereafter, the wind park is integrated with a regional grid, owned by Fortum Distribution AB. In addition to that, the electricity generated from the wind park is also calculated in this project. Later on, the work is devoted to finding the static and dynamic line ratings for “VL3” overhead conductor by using IEEE-738-2006 standard. Furthermore, the project also deals with finding the line current.and making its comparison with maximum capacity of overhead conductor (VL3) for loading it in such a way that no any violation of safe ground clearance requirements is observed at all. Besides, the line current. knowing the conductor temperature when it transmits the required electricity in the presence of wind power generation is also an important factor to be taken into consideration. Therefore, based on real-time ambient conditions with actual line loading and with the help of IEEE-738-2006 standard, the conductor temperature is also calculated in this project. At the end, an economic analysis is performed to evaluate the financia

关键词： Overhead Conductor Static and Dynamic Ampacities Real-Time Weather Conditions Static and Dynamic Line Rating Techniques Wind Power Integration Regional Grid Line current. Conductor Temperature Wind Power Economics Dynamic Line Rating Economics

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