起始電壓 的英文怎麼說
中文拼音 [qǐshǐdiànyā]
起始電壓
英文
initial voltage- 起 : 起Ⅰ動詞1 (站起; 坐起) rise; get up; stand up 2 (取出; 取走) draw out; remove; extract; pull 3...
- 始 : Ⅰ名詞1 (最初; 起頭) beginning; start 2 (姓氏) a surname Ⅱ動詞(開始) start; begin Ⅲ副詞[書面...
- 電 : Ⅰ名詞1 (有電荷存在和電荷變化的現象) electricity 2 (電報) telegram; cable Ⅱ動詞1 (觸電) give...
- 壓 : 壓構詞成分。
- 起始 : origin; origination; parentage; germ; initiation
- 電壓 : voltage; electric tension; electric voltage
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For the bldcm which has a pseudo - sinusoidal back - emf waveform, this dissertation presents a svpwm control method using six discrete position signals for minimizing the torque ripple. the main aspects for the implementation of this method are analyzed, including the initial orientation of the voltage vector, reasonable choice of the impedance angle and the advance commutation angle, and estimation of the successive rotor positions
針對反電動勢類似正弦的準正弦波反電動勢無刷直流電動機,本文提出一種基於六個離散位置信號的自同步svpwm (電壓空間矢量法)控制方法,用以削弱電磁轉矩脈動,分析了實現這種方法的主要控制環節,包括起動時電壓空間矢量的初始定位,阻抗角與電流超前角的合理選擇以及連續轉子位置的估計等。Electrical field stress at the icicle tips is even stronger. at these areas, if the electric field across air gaps is high enough, corona discharges are initiated. this can lead to the development of local arcs across the air gaps causing a substantial increase in leakage current and a concomitant melting of ice
空氣間隙的存在使覆冰絕緣子表面的電場分佈發生了明顯畸變,間隙上承受了非常高的電壓,這使得冰凌尖端的電場變得相當強,一旦電場達到了電暈的起始電場,局部放電就在這一區域發生,進而產生局部電弧並逐漸發展成整串的閃絡,泄漏電流迅速增大,同時伴隨著冰的融化。In light of the limitation of fast fourier transform ( fft ) for the method of traditional spectrum analysis to analyze the unsteady signal, wavelet and wavelet analysis are made for the typical unsteady process signal of starting up and shut down with the good characteristic of simultaneous localization in both the time and the frequency domains based on the field test on the vibration of two - row placed units in lijiaxia hydropower station, in which the signal is decomposed into different frequency band, and then the weak signal is caught and the dominant frequency is picked up for the analysis of the vibration source
摘要基於李家峽水電站雙排機組振動的現場試驗研究,並且針對傳統頻譜分析方法傅立葉變換( fft )對于非平穩信號已力不從心這一缺陷,利用小波分析方法在時域和頻域上同時具有良好的局部化性質,通過對開停機這一典型非平穩過程信號進行小波及小波包分析,將其分解到不同頻帶內,獲取微弱信息和提取優勢頻率,並對其作振源分析,得出開停機初始時刻因水流不穩均出現強烈的振動現象,且低頻段信號能量最大,開停機過程水流脈動壓力和尾水渦帶擺動是引起定子基礎振動的主要原因。In order to solve the problems of flux estimation using the voltage model, such as the initial value and the drift of pure integrator, a flux - observer - based method is applied
利用磁通觀測器,可避免用電壓模型推算轉子磁通時遇到的積分運算問題(初始值確定和誤差積累引起的積分漂移) 。In order to improve the quality of the voltage signals, this paper has adopted the scheme of three phases and six organs in signal - generator part, which can eliminate the errors caused by the assembly warp and the zero shift of organs. this paper also has analyzed the distribution and varying rules of the magnetic field in the signal - generator part, then based on the conclusion of the analysis improved the structure of signal - generator, which could completely eliminate the noise signal caused by the roughness of the face on the magnetic steel ring. the improvement not only met the requirement of this study, but established the theory foundation for the super - high precision magnetic encoder in future research
因此,為提高原始電壓信號的質量,本文採用三相六元件的信號發生方案,通過差分處理濾除了由於裝配偏差和零點漂移帶來的信號誤差;本文對編碼器信號發生結構進行了磁場分析,依據磁場分析的結論對編碼器常用的信號發生結構進行了改進,改進后的結構利用積分原理在理論上能夠完全消除信號中由磁鋼環表面粗糙度引起的信號噪聲,進一步提高了信號質量,此結構不僅滿足了本課題的需要,而且為今後研製超高精度的磁電式編碼器奠定了理論基礎。Calculation of preliminary winding parameters and changing laws of several rectifier transformers and furnace transformers
幾種整流變壓器和電爐變壓器繞組起始參數計算及其變化規律Due to their high aspect ratios and small tip radii of curvature, carbon nanotubes possess marvelous electron field emission properties, viz. low turn - on voltage ( e0 ) and large emission current density ( je ), and have good potential for using as materials in electron emitters of flat panel display
由於奈米碳管具有極高的縱橫比與極小的尖端曲率半徑,因此奈米碳管有著超乎常態的電子場發射特性,低的場發射起始電壓與大的場發射電流密度,使其為電子場發射平面顯示器的良好材料。Abstract : on the basis of the theory of controlled phase - changes of piezoceramics, high - temperature polarizing technology makes initial working temperature a little higher than curie temperature of a sample, but the polarization voltage needed is greatly lower than the one needed in normal polarization ( only 1 / 10 - 1 / 5 ). the improved polarizing technology can make polarization more complete
文摘:壓電陶瓷的高溫極化是利用受控的場致有序化的順電鐵電相變原理,使起始極化溫度略高於樣品的居里溫度,但所需的極化電壓大大低於常規極化,僅為1 / 10 - 1 / 5 ;選擇較高的降溫升壓速率,可使極化趨于更加完全,具有常規極化工藝無可比擬的優越性。By applying related theory of gas discharge and mathematical statistics, this paper more in - depth and systemic study the influence of the length of air gap, ice state, water conductivity and air pressure on the inception corona and pulse discharge characteristics, included the discharge frequency, discharge amplitude and time interval
根據試驗結果,用氣體放電和數理統計方法,分析了覆冰水電導率、冰的狀態(乾冰和濕冰) 、空氣間隙長度、氣壓和施加電壓等參數的變化對間隙模型的起始放電電壓、脈沖放電特性、放電頻率、放電幅值和時間間隔等的影響。Ultrasonic motors are a new kind of solid actuators that come into being since 1980 ’ s, which use inverse piezoelectric effect of pzt to excite stator ’ s elliptical vibration and produce driving power by frictional coupling
超聲波馬達是上世紀80年代開始發展起來的一種新型驅動器,它是利用壓電陶瓷的逆壓電效應激勵出定子表面質點的橢圓軌跡振動,依靠摩擦耦合來實現驅動。The calculation of the reaction time for the high initial response excitation system
高起始響應勵磁系統電壓響應時間的計算Firstly, this paper introduces the asynchronous motor model, and compares it with the dc motor ’ s. then the paper studies the principle of vector control, and proposes an improved current model of rotor flux observer. this paper also studies the three - level inverter ’ s topology, working principle, the neutral - potential unbalance mechanism and its controlling strategy. the paper especially studies the svpwm in details. the interface between the vector control and the three - level inverter is studied in details, including the generation of reference voltage vector, its judging of the sector and triangular regions, and the working mechanism after it sent into three - level inverter. when synthesizing the reference voltage vector, select the vector which only includes p and o states as the starting vector, thus eliminate the vector shift problem when sector changes. this paper fully takes advantages of the powerful functions of matlab / simulink to set up the simulation model. this construction is very explicit. the simulation results verify the inverter voltage output is correct, the rotor flux is steady, the asynchronous motor ’ s dynamic and steady state performances and speed modulation are excellent
本文首先介紹了異步電機的數學模型,在此基礎上將異步電機的數學模型與直流電機的數學模型進行了比較;然後介紹了矢量控制的基本原理,採用了一種改進的轉子磁鏈電流型觀測模型;對三電平逆變器的電路拓撲、工作原理、中點電位不平衡的機理及控制方法進行了介紹,詳細分析了空間矢量脈寬調制策略。本文對異步電機的矢量控制與三電平逆變器之間的介面進行了詳細的研究,包括:參考電壓矢量的形成、所落扇區與具體小三角形區域的判斷、送入逆變器之後的工作機理。在參考電壓矢量的合成時,選擇只包含p 、 o狀態的空間電壓矢量作為起始矢量,解決了扇區切換時的矢量突變問題。Insulating liquids - determination of the partial discharge inception voltage - test procedure
絕緣液體局部放電起始電壓測定試驗程序Abstract : the initial charge - process of dc capacitor and the steady working state of active voltage - source - inverter power filters are analyzed in this paper, and four new parameters are proposed to judge the working performance of active power filters and to aid their design
文摘:分析了電壓逆變器型單相有源電力濾波器直流側儲能電容器的初始充電過程(有源電力濾波器的起動過程)和有源電力濾波器的穩定工作狀態,並提出了判定有源電力濾波器性能、幫助有源電力濾波器設計的四個標識性參數。The density of its field emission catelectrode tip is about 24000tip / mm2, the onset emission voltage is 0. 5 ~ iv, the backward voltage is larger than 25v, the current of single tip is 0. 2na, the sensitivity is 98. 5mv / bar
其場致發射陰極錐尖陣列密度達24000個mm ~ 2 ,起始發射電壓為1 5v ,反向電壓25v ,當正向電壓為5v時,單尖發射電流為0 . 2na ,壓力靈敏度為98 . 5mv bar 。In large rotating machinery using filmatic bearing ( turbogenerator, air compressor, etc. ) there is a potential trouble from impefect installation or running conditions, a metals " contact between rotors and shells. the trouble is usully called rubbing. the advantage of ae technologe in the rubbing diagnosis and early detection is showed. instead of classical ae characteristic parameters ( counts, amplitude, energy, duration and the other ones ) a new feature extraction by frequency analysis of ae envelop signals is discussed. both research of ae process and field experements indicate that periodic components in the envelop spectrum related to rotational speed increase evidently at the beginning of rubbing production, hence are highly sensitive to the rubbing fault diagnosis. according to the new design an acoustic emission equipment for the rubbing diagnosis named buaa ae testing system is developed and described
汽輪發電機、空氣壓縮機等採用油膜支撐的大型轉動機械,由於安裝或運行中的原因,在轉子旋轉過程中,可能和器壁發生輕微的摩擦和碰擊,簡稱碰摩.聲發射技術在碰摩發生特別是故障早期診斷上有優越性.本系統的特點是沒有沿用傳統的計數、幅度、能量和持續時間等聲發射特性參數,而是在聲發射包絡信號的頻率分析中進行特徵提取.聲發射發生的過程分析和現場試驗都表明這種方法對碰摩檢測很敏感,在碰摩發生的起始階段,包絡譜中與轉速同步的周期性分量顯著增加.根據這種新的設計思想自行研製了buaa碰摩聲發射檢測儀並對此作了介紹Observation of local discharge. phenomena on charged surface of dielectric films
帶電介質板表面放電流柱起始電壓的實驗研究The experimental results are the following : 1 the resistivity changing features of rock show rise - smooth - drop, and the smooth segment is very short and unobvious. 2 the time of first drop for the apparent resistivity is earlier than all other loading experimental results, the rupture stress about moves up by 10 per cent. viz : the apparent resistivity starting drop when axial rupture stress increases about 40 per cent for the array parallel to the axial ; the apparent resistivity starting drop when axial rupture stress reaches about one - third for the arrays non - parallel to the axial
即:平行於軸壓方向的測道,在軸向破裂應力的40 %左右開始下降不平行軸壓方向的測道,視電現率約在1 3軸向破裂應力開始下降3電阻率從開始下降起,下降速率逐漸增加,但增加得很緩慢,巖石大破裂前,單位軸向應力變化引起的視電阻率變化幅度也不是很大。分享友人