正向磁化 的英文怎麼說
中文拼音 [zhēngxiàngcíhuà]
正向磁化
英文
normal magnetization-
Based on the thorough investigation of the post - regulation and efficiency in multiple output switching - mode power supplies, an optimal combination topology for multiple output switching converter is presented in this thesis, which is consisted of forward converter with active clamp ( fac ), synchronous rectification ( sr ) techniques and magnetic amplifier technique ( magamp )
本文通過研究分析近年來多路輸出開關電源輔助輸出電壓調節和提高效率的方案，面對開關電源朝著輸出低電壓大電流方向發展的趨勢，提出多路輸出開關電源新的拓撲優化組合模式? ?有源鉗位正激變換器、同步整流技術、磁放大器。The second, at the high frequency primary coil, when switch turn on with control signal ( the spwm pulse is modulated ), in the positive or negative semi - period of low frequency modulation signal, transformer coil with same direction voltage. the magnetic flux of transformer core will increase step by step. at the end, it leads to magnetic flux saturation
二、在高頻變壓器原邊，當開關管接收控制信號脈沖列（經調制的spwm波列）導通時，在低頻調制信號的正半周或負半周內，施加在變壓器繞組上的是同一方向的電壓，變壓器磁芯中的磁通可能將級進地逐漸增加，導致磁芯飽和，造成磁偏或單向磁化，導致低頻電信號放大失真或由於很大的磁化電流而無法正常工作。To improve the capability of the bearing - less slice permanent motor, to reduce the ullage of the motor and the badly additive torque, i design optimization the structure of the rotor pm, and two projects are proposed. one is four pieces rotor pm which is the same magnetized and the other is eight pieces rotor pm which is different magnetized direction
為了進一步改善片狀無軸承永磁電機的動態性能，減小電機的損耗及有害的附加轉矩，優化設計了轉子永磁貼片的結構，提出了四片同向充磁和八片正反向充磁兩種方案。For parameter a, there is a close relationship exist between a ( 9, sr ) in two different radar incident angle that can be expressed as : with considering the effects of soil texture, we get the final expression of the inversion model : where mv ( t1 ), mv ( t2 ) is volumetric soil moisture content in two different temp, c, d is soil type related parameters, and v ( t1 ), s ( t2 ) is coresponding bare soil radar backscattering coefficients. inversion results show that for the c band hh polarized radarsat scansar data with a range of incidence angle from 20 to 40, the soil moisture change value can be derived with an acceptable accuracy using the above model. the temporal and spatial soil moisture change patterns are associated with rainfall and vegetation cover, as well as the soil hydraulic characteristics
利用最新發展的電磁波散射模型研究了不同植被覆蓋地表雷達波對地表土壤水分的敏感性，建立了半經驗植被雷達後向散射模型; 2 ） .研究發現在農作物等矮小植被覆蓋地表，植被層直接後向散射與植被類型相關，且在植被生長期，雷達後向散射系數對植被含水量的敏感性要高於對植被高度變化的敏感性; 3 ） .解決了單參數雷達地表土壤水分反演問題中，雷達入射角和地表粗糙度的影響這一難點問題; 4 ） .利用土壤介電模型校正了不同土壤類型對反演地表土壤體積含水量的影響; 5 ） .在以上成果基礎上，建立了完整的單參數雷達地表土壤水分變化探測反演演算法，經地表驗證，模型反演地表土壤水分變化值的精度為rmse = 0According to more effect, when the hore component is placed in a gradient field, at the same time the direction of the current is perpendicular to the direction of the voltage, then between the two parallel side face come out the hore voltage. when hore component is set in this kind of uni - gradient magnetic field and the electric current is unchanged, the voltage output of hore component will be proportional to the position of the hore component in the magnetic field. so we can use the hore component to measure the movement of hore component against magnetic field
根據霍爾效應可知，置於磁場中的霍爾元件若電流方向與磁場方向垂直，則在霍爾元件垂直於磁場和電流方向的兩個側面將產生電勢，將霍爾元件置於強度隨空間位置線性變化的磁場中，且控制電流恆定，輸出就正比于霍爾元件處于磁場中的位置，因此可以用霍爾元件來測量磁場與霍爾元件間的相對位移量。Aim at the dtc ' s blemish mentioned above and the direction of dtc technique development, the dissertation put great emphasis on the work as follows, with an eye to exalt dtc system function : ( 1 ) a new speed - flux observer of an induction motor is proposed to enhance the accuracy of flux observing, which is an adaptive closed - loop flux observer and different from the traditions. a new adaptive speed - observation - way is deduced out according to the popov ' s stability theories ; ( 2 ) to improve the performance of dtc at low speed operation, we have to exalt the accuracy of the stator flux estimation and a new way of bp neural network based on extended pidbp algorithm is given to estimate and tune the stator resistance of an induction motor to increase the accuracy of the stator flux estimation ; ( 3 ) digital signal processor is adopted to realize digital control. an device of direct torque control system is designed for experiment using tms320lf2407 chip produced by ti company ; ( 4 ) bring up a distributed direct torque control system based on sercos bus, sercos stand for serial real time communication system agreement which is most in keeping with synchronous with moderate motor control ; ( 5 ) the basic design frame of the hardware and software of the whole control system is given here and some concrete problem in the experiments is described here in detail
針對上面提到的直接轉矩控制的缺陷和未來直接轉矩控制技術發展方向，本論文重點做了以下幾個方面的工作，目的在於提高dtc系統的綜合性能： （ 1 ）提出一種新型的速度磁鏈觀測器，新型的速度磁鏈觀測器採用自適應閉環磁鏈觀測器代替傳統的積分器從而提高磁鏈觀測的精度，並且根據popov超穩定性理論推導出轉速的新型自適應收斂律； （ 2 ）改善系統的低速運行性能，主要從提高低速時對定子磁鏈的估計精度入手，提出了一種提高定子磁鏈觀測精度的新思路? ?利用基於bp網路增廣pidbp學習演算法來實時在線地修正定子電阻參數； （ 3 ）採用數字信號處理器dsp實現系統全數字化硬體控制，結合ti公司生產的tms320lf2407晶元，設計了直接轉矩控制系統的實驗裝置； （ 4 ）提出了基於sercos總線網路化分散式的直接轉矩控制系統， sercos （ serialrealtimecommunicationsystem ）是目前最適合同步和協調控制的串列實時通信協議； （ 5 ）基本勾勒出整個控制系統的硬體和軟體設計基本框架，詳細描述一些實驗中的具體的細節問題。In order to decrease the cost, simplify the structure of the pmsm servo system and at the same has no effect on the system performance, this paper uses hall element as the position sensor, which has very low solution but very low cost, and in order to realize sinusoidal current drive of pmsm, this paper presents a new rotor position estimator based on flux estimation
為了降低成本，簡化系統，本文採用低解析度的霍爾元件作為pmsm伺服系統的位置傳感器，採用基於磁鏈觀測法的低解析度位置傳感器控制技術，來估計電機轉子的實時位置和轉速，實現電流的正弦換向，減小轉矩脈動。This paper has studied the mean attenuation, scattering, and back scattering cross sections of groups of small rotating spheroids about characteristics of microwave scattering when their rotatory axes are oriented at random in any direction in 2d plane and 3d space respectively under the condition of normal distribution, and that those physical quantities are changed with different variance, expectation and wave lengths of incident electromagnetic wave
本文研究旋轉軸方向分別在平面內和空間中隨機取向呈正態分佈時的小旋轉橢球粒子群的平均衰減截面、平均散射截面、平均後向散射截面等微波散射特徵，以及這些物理量隨軸向分佈期望、方差及入射電磁波波長的變化。It is found from the experiment that under the conditions of peak magnetic field of 0. 57t, beam pulse fwhm ( full width of half maximum ) of 44ns, a microwave radiation pulse with fwhm 25ns and whole width of 35ns is produced, when the intensity of the guiding magnetic field rises, the peak microwave power changes little but the width of the pulse reduces. the a - k gap also has obvious influence on the microwave radiation, the stable and higher microwave output is obtained under suitable gap
實驗中還發現，在峰值磁場0 . 57t和束流半高寬44ns情況下，得到了25ns半高寬和35ns底寬的微波脈沖信號，隨著導引磁場增加，微波信號幅值基本不變，但國防科學技術大學研究生院學位論文是微波脈沖寬度會逐步減少;實驗中還發現磁場線圈位置有一定的軸向調節范圍，說明在磁場軸向分佈的一定變化范圍內，器件都可以正常工作，這對以後的永磁場系統導引的微波實驗有利。The current estimated normalized magnetic field direction, corrected for the fields generated by the torque coils
目前經由修正轉矩線圈產生的磁場而估計到的正規化磁場方向。Several influence factors to result plasma drift in hainan were analyzed. in this paper the characteristics of ionospheric parameters variation were analyzed systematically and some new results in storm - time such as seasonal behaviors were obtained ; it is the first time to investigate the ionospheric drift behavior in hainan and some new results was obtained, the relationships between each two plasma drift velocity components in storm time in hainan were found and the electric filed variation in hainan ionosphere also was obtained ; the results also show that there are big differences of the ionosphere parameters bo and bl obtained from the data with that obtained from the iri - 2001 applied for hainan ; a new phenomena was found during a strong magnetic storm, that a layer with very strong electron density and density grad was found during the recovery phase of the storm, its horizontal scale is beyond 100km and temporal scale is about 2 hours, this phenomena repeated 3 times continuously. a type of negative disturbance in high and low latitude but positive disturbance in east - asia also has been found
本文較為系統地給出了海南地區電離層的參數變化特徵，特別是得到了一些暴時與以往不同的季節特性；第一次給出了海南地區的電離層等離子體漂移特徵，發現等離子體漂移暴時擾動在三個方向上有內在的聯系，得到了電場變化曲線；研究結果還表明海南電離層的半厚指數和形狀參數等與國際參考電離層iri - 2001存在很大差別；通過對強磁擾動事件期間的參數變化特性分析發現，在磁暴恢復相期間海南地區電離層底部存在一個電子密度非常大的高密度區，高密度區底部電子密度梯度隨高度急劇增加，該區域的水平尺度可達100公里以上時間尺度約為2小時，連續出現過三次，這是一個在海南從來未發現的新現象；研究還發現了暴時東亞地區電離層擾動會出現高低緯負相而中緯正相的現象。Then with the introduction of the expression of radial electric field and azimuth magnetic field, the movement tracks of electrons in the interaction space are modified on account of the azimuth magnetic field decreasing with the decrease of the axial current
接著，引入同軸系統中徑向電場和角向磁場的表達式，並且考慮到軸向電流的逐漸減小會導致角向磁場沿軸向的變化，推出修正後的電子運動軌跡表達式。Simulations for these two conditions prove validity of theoretical analysis. on the basis of this scheme, a new speed adjustment strategy about vector control of doubly fed motor based on rotor current vector fixing is given. it introduces the closed - loop of stator excitation current to the system, which increases two adjustment channels : speed and excitation adjustment
經理論分析可知，該方案中，由於轉子電流與磁鏈無法實現完全解耦，故僅在亞同步工況下有效，在超同步時則會因為調速系統不能自動校正轉子磁鏈幅值變化引起的橫向電流而使系統失去控制，無法達到穩定狀態。In order to increase the utilization of transformer core and reduce the number of transformers, the two - transisteor integrated - magnetics forward converter is studied in this paper. the phenomena about magnetic deviation due to asynchronism of duty cycle and other parameters is analyed, and the converter works normally although there is magnetic deviation. the working principle of circling current is analyed, and a improving circuit is present to decrease the circling current
分析了雙管正激磁集成變換器的環流產生機理，提出了一種減小環流的方法；研究了占空比等參數不一致導致的磁芯偏磁問題，磁芯存在單向磁化現象，但不會出現單向磁飽和，變換器仍能穩定工作。When the twist causes the reversed flux patch to lie closer to the geographic pole than the normal flux patch, the result is a weakening of the dipole, which is most sensitive to changes near its poles
如果扭曲所造成的反向通量斑塊，比正常通量的斑塊更靠近地理極點，則會使磁偶極減弱，因為磁偶極對于在極點附近的變化最敏感。分享友人