負性電 的英文怎麼說
中文拼音 [fùxìngdiàn]
負性電
英文
negativity-
In this paper, a kind of output current feed - forward circuit is added into the input of the current loop. by adding this compensatory circuit, the output character of the inverter is improved greatly
本文還研究了一種提高逆變器輸出電壓外特性的思路，通過將負載電流正反饋給逆變器的電流環輸入端，從而達到提高輸出電壓的外特性的目的。In the positioning servo - system, which generally is configured by the d. c. pulse width modulator ( pwm ) velocity governing system and position servo - loop, the parameter perturbance of pwm velocity loop really exist by reason of such as the load behavior ; power voltage supply ; operating setting value, etc. 1, 2 ， and it cannot be ignored. by using the identification technique to form the mathematical model of the system, authors have confirmed the facts. therefore, to design the discrete sliding mode controller ( dsmc ) of the positioning servo - system, the perturbed parameters value bounds of the pwm velocity loop, which is as the controlled plant of position servo - loop, should be accounted. consequently, the design principle of dsmc for accounting system with parameter perturbance is proposed by the authors. the proposed method can ensure the stability of system with parameter perturbance and the behavior of non - overshoot, fast precise positioning. in order to reveal the effects of the design method, the comparative research work is done by the authors. also, it has been tested in an industrial experiment, the results proved it is satisfactory
由直流脈寬調速系統（ pwm ）和位置環構成的定位系統中，速度環的參數隨負載特性；電網電壓；給定工況而攝動是不容忽視的.作者通過系統辨識建模也證實了這一事實1 ， 2 .因此在設計位置環的離散滑模控制時，必須針對速度環（即位置環的控制對象）的參數攝動范圍採用「對象參數攝動離散滑模控制器的設計方法」 ，以確保系統在參數攝動時的穩定性和快速、無超調、準確定位的優良動態品質.為剖析該設計方法的控制效果，本文作了對比性研究，並將該設計方法用於工業試驗中，取得了滿意的結果The safety of transmission line plays a important role in power system safety it is not only the requirement of ensure supply power reliability, but also the necessary precondition of enhance power system stabilization, to remove faulty line quickly and accurately, also keep non - faulty line continuous work when some transmission line faults current differential protection is a kind of simple, reliable and good - selective protection manner to any variety of transmission lines, power system development needs current differential protection apply to transmission lines, moreover the advancement of electric and communication technology enable current differential protection apply to transmission lines firstly, the paper discusses, analyses the research and application transmission line protection in detail, compare the principle and realistic presupposition of general line pilot protections secondly, because conventional current vector differential protection are influenced easily by load current and transitional resistance, in order to at the same time quicken protection act, the principle and criterion include work characteristic of differential protect based on fault component sampled values are studied, results shows that differential protect based on fault component sampled values excels general vector current differential protection in reliability, sensitivity and anti - saturation of current transformer in addition, synchronous current sampling methods at all terminals of line is analyzed and estimated lastly, the principle and criterion. also device design about current sampling values differential protection based on optical fiber communication, which apply to short transmission lines are concretely investigated,
基於基爾霍夫定律的電流差動保護無論對於何種形式的輸電線路都是一種簡單、可靠、選擇性強的保護形式，電力系統的發展使得電流差動保護應用於線路保護成為需要，而電子、通信技術的發展使得電流差動保護應用於輸電線路成為可能。首先，本文對目前線路保護的研究和實際應用情況進行了討論和分析，比較了常用線路縱聯保護的實現原理和實現條件及優缺點。其次，針對常規相量電流差動保護易受正常負荷電流和故障過渡電阻影響的缺點，同時為加快差動保護的動作速度，對基於故障分量瞬時采樣值電流差動保護的原理、判據、動作特性等作了討論和分析，結果表明基於故障分量瞬時采樣值電流差動保護在可靠性、靈敏度、抗電流互感器飽和方面明顯優于常規相量電流差動保護，對電流差動保護各端的同步采樣方法和數據通信也進行了分析和評價。All analysis and simulations results indicate several methods improving the insulation recovery of spark gap switch : ( 1 ) using the gas with good thermal conductivity, such as h2 and sf6 ; ( 2 ) using the gas flow ; ( 3 ) utilizing the v / p cure ; ( 4 ) modifying the geometry and size of the electrode ; ( 5 ) using the gas with good electronegativity, such as sf6. some experiments on the multi - pulse operation of high power spark gap switch are carried out. the insulation recoveries of switch without and with gas flow are both investigated
結合理論分析和模擬結果，提出了氣體火花開關多脈沖運行特性可採用如下方法: （ 1 ）使用導熱性能好的氣體，如h2 、 sf6等; （ 2 ）採用吹氣的方法; （ 3 ）增大氣壓，在電極表面增加細小結構，構造平穩的v / p曲線; （ 4 ）改良開關電極結構和尺寸，採用奶頭-半球結構的電極; （ 5 ）使用電負性強的氣體作為開關絕緣氣體，如sf6 。The system parameters are developed at the same time, and some universal conclusions on the theoretical analysis of pll are reached. then, we have carried on analysis and research to the theory of differential delay ring voltage controlled oscillator ( vco ). on this basis, a improved differential delay ring vco with more efficient loads is described. this circuit has been designed and implemented in 0. 35 m cmos technology
本文還對差分延遲結構環形壓控振蕩器電路進行了深入的分析與研究，並提出了一種基於高質量電阻電路的主從差分延遲結構環形壓控振蕩器，其採用了一種新型的主從差分延遲結構，並用一個更有效、更穩定的負載電阻電路結構來替代vco設計常使用的單個mos管電阻結構，使其系統穩定性有了相應提高。The typical performance characteristics include : line and load transient response, efficiency, output voltage ripple, quiescent current, maximum load current, output voltage temperature characteristics and the short
其中，整體模擬指標包括:晶元線性調整率和負載調整率、轉換效率、輸出電壓紋波、晶元靜態電流、最大負載電流、輸出電壓溫度特性及短路負載電流。Combined with researches on propagation characteristics, the micro - current sensor for on - line pd monitoring is developed and the effects of coil number, stray capacitance and loading resistance on pass - band and sensitivity are also studied
同時，結合傳播特性，研究了局部放電在線監測寬帶微電流傳感器，並就線圈匝數、雜散電容和負載電阻等對傳感器通頻帶、靈敏度等性能參數的影響進行了分析。As the experiment results show, multiple reasons led to the offset of oscillating frequency, including diode ’ s nonlinear characteristic, fluctuation of electrical source voltage, traction of load impedance, change of environmental temperature and humidity and the design of circuit
實驗結果表明多種因素引起了振蕩頻率的偏移，包括二極體的非線性、電源電壓的波動、負載的牽引、環境溫度濕度變化以及電路板設計方面的因素等。When the flue gas and dust past through electrical fields, they caused impact with positive and negative ion and electron between electrical electrodes to charge electric. the charged particles move and are accumulated to difficult electrical electrode due to effect of electric field force. through rapping method, the dust leaves electric electrodes and drop into the collection hopper, and the remove the dust by transportation system
是一種煙氣凈化設備，它的工作原理是：煙氣中灰塵塵粒通過高壓靜電場時，與電極間的正負離子和電子發生碰撞而荷電或在離子擴散運動中荷電，帶上電子和離子的塵粒在電場力的作用下向異性電極運動並積附在異性電極上，通過振打等方式使電極上的灰塵落入收集灰斗中，使通過電除塵器的煙氣得到凈化，達到保護大氣，保護環境的目的。To explain this, we ' re going to avoid the idea of impedance ( which has resistive, capacitive and inductive components, some of which vary in effect by frequency, thus varying the actual loading ) and use pure resistance to describe the concept
為了便於解釋，我們準備暫時避免使用阻抗這一概念，因為它有電阻性、電容性和電感性成分，而其中一部分會隨著頻率的變化而變化，從而改變了實際的負載。This paper analyses the test results gained by mixed simulation, and validates the reliability of the use of transient zero current and negative current in fault identifying
文中討論了負序電流的分佈及提取問題，試驗數據同樣表明負序電流用於單相接地故障識別是可行性的。So it can be used for single - phase fault identifying. this paper discusses the size of the negative current and the method of analyzing it. numeral simulation shows the feasibility of it
由於負序電流在故障線路和非故障線路上具有顯著差異，故本文也研究了將負序電流作為故障特徵量的可行性。The modified copolymer solution has lower surface tension than the unmodified one. by measuring adsorptive content, we find that the adsorptive content of fdn superplasticizer is higher than the modified copolymers, but their adsorptive shape on the surface of the cement particles is different. measuring of potential of cement particle indicated that higher potential leads to better dispersibility for used superplasticizer
通過對減水劑的表面張力、吸附量、 5電位研究，發現改性后的減水劑均比未改性的共聚物更能降低水的表面張力；茶系減水劑比合成的減水劑具有更大的飽和吸附量，但彼此的在水泥顆粒表面的吸附形態並不相同：減水劑一水一水泥體系具有雙電層，加了減水劑的水泥膠粒的電負性顯著增加，改性后產物的負電性與改性前相比明顯增加。The main work and conclusion for this paper is as following : according to the flashover test results of several kinds of iced insulators under positive voltage and negative voltage, this paper obtained : for the single porcelain insulator, the single glass insulator and the composite insulator bridged completely by icicle, the metal cathode ' s strong ability of emission electron is the primary reason that results in the lower negative flashover voltage ; the position difference of the high resistance district in method anode side results in that porcelain insulator cluster and glass insulator cluster have an evident effect of polarity ; when less ice and no icicle at the brim of the sheds, due to numerous non - polar arcs on the composite surface, the effects of polarity of composite insulator was lost using the test method of the average flashover voltage in the freezing period, dc flashover performances were investigated of several insulators with some typical structures and different material
本文的主要工作和結論如下：在人工氣候室內，根據不同覆冰絕緣子正、負極性下的閃絡試驗結果，得出負極性電弧金屬陰極的強電子發射能力造成了單片瓷、玻璃絕緣子及被冰凌橋接的合成絕緣子有較低負極性冰閃電壓；正極性電弧金屬陽極側產生高電阻區所處位置的差異使得瓷和玻璃絕緣子串具有明顯的極性效應；覆冰較少時，合成絕緣子表面出現數量較多的非極性電弧使合成絕緣子無極性效應。利用覆冰期內平均閃絡電壓的試驗方法，對不同材質和結構的絕緣子在覆冰、低氣壓和污穢共存環境中的直流閃絡特性進行了研究。試驗結果表明，直流平均閃絡電壓隨著海拔的升高、覆冰量的增加以及污穢度的增加而降低，且其特徵指數與絕緣子結構、覆冰量、覆冰狀態、污穢度等有關。Zirconiated tungsten electrodes have good performance in ac welding. especially under high load current its excellent performance can not be replaced by any other products
鋯鎢電極在交流條件下，焊接性能良好；尤其在高負載電流的情況下，鋯鎢電極表現出良好的優越性能。It balls up well in ac welding and has a more stable arc than pure tungsten. especially with excellent performance in high load ac welding, it is not replacable by any other electrodes. it also resists contamination well in ac welding
尤其在高負載電流的情況下，鋯鎢電極表現出來的優越性能，是其他電極不可替代的，在焊接時，鋯鎢電極的端部能保持成圓球狀而減少滲鎢現象，並具有良好的抗腐蝕性。Unified power flow controller ( upfc ) is one of the most powerful and most promising controllers of facts. if we use upfc to control the transmission parameters, terminal voltage, line impedance and phase angle in normal situation and use it to compensate zero sequence and negative sequence currents when one of transmission lines is cut off, we can implement two phases operating in high voltage transmission lines, which can improve stability and reliability for the transmission system
統一潮流控制器（ upfc ）是功能最強、最具發展潛力的靈活交流輸電系統（ facts ）控制器之一，如果在常規條件下，用upfc實現輸電線路的電壓調節、移相、潮流控制、阻尼振蕩等功能，在發生單相永久性接地或單相斷路故障時，由傳統的三相跳閘改為單相跳閘，用upfc的並補來濾除兩端系統的零序和負序電流，用upfc的串補來提高輸電線的傳輸功率，以實現兩相長期運行，那麼輸電系統的穩定性、可靠性將大大提高。Recommended practice for establishing transformer capability when supplying nonsinusoidal load currents
施加非正弦負載電流的變壓器性能確定的推薦規程Five different structures are described : standard transformer coupling, parafeed, resistively loaded stage capacitively coupled to the output transformer, tube ( valve ) based constant current source load capacitively coupled to the output transformer, and solid state ( mos fet ) constant current source load capacitively coupled to the output transformer
我們將討論五種不同的方式：標準變壓器耦合；旁饋耦合；電阻性負載電容性耦合至輸出變壓器；膽恆流源負載電容性耦合至輸出變壓器；以及晶體管恆流源負載電容性耦合至輸出變壓器。Tangyin substation is an important substation which has two transformer of 120mva, eight 220kv lines and three 110kv lines. tangqian line is a 110kv line specially for traction transformer substation. because traction load is high - power nonlinear and asymmetry. it will produce much harmonic and negatvie sequence current, which have done harm to compensation capacitors of tangyin substation. in recent years, the tang6c capacitor often interrupted and in 2001 july the tang7c capacitor ' s discharge pt exploded
湯陰變電站是豫北一座樞紐變電站，有2臺120mva的主變， 8條220kv線路和3條110kv線路，其中的湯牽線是專為牽引變電站供電的110kv線路。由於電力機車屬于大功率的非線性負荷，且三相不對稱，在其運行過程中必然會產生較大的高次諧波和負序電流。分享友人