磁通反轉量 的英文怎麼說
中文拼音 [cítōngfǎnzhuǎnliáng]
磁通反轉量
英文
frpi flux reversal per inch-
The airborne electric resistance mapping technique, lies in the conversion of measured airborne electromagnetic field signal into apparent electric resistance value that reflects underground strata through inversion or graticule transformation technique
摘要航空電阻率填圖是通過反演或量板轉換技術把測量到的航空電磁場信號換算成反映地下巖層的視電阻率值。For an actual planetwide polarity reversal to occur, such a reversed flux patch would grow and engulf the entire polar region ; at the same time, a similar change in overall regional magnetic polarity would take place near the other geographic pole
如果整個行星的磁極要真的反轉,反向通量斑塊需擴大到涵蓋整個極區;同時,另一個地理極點附近也會發生類似的區域極性全面變化。Flux position & error in flux magnitude and error in torque are used as fuzzy state variables. fuzzy logic is used for choosing the switching state. a fuzzy logic controller can choose the switching states according to a set of fuzzy rules based on both specialists " experience and knowledge, which improves the response performance of the system effectively during start - up and change in load
作為本文的一個創新點,針對普通的直接轉矩控制在給定轉矩躍變時反應較慢的缺點,提出了一種模糊控制器,把磁鏈位置、磁鏈誤差和轉矩誤差作為模糊輸入變量,應用模糊邏輯來確定逆變器的開關狀態,該模糊控制器根據一套基於專家經驗和知識的模糊規則來選擇開關狀態,從而有效地提高了系統在啟動和負載突變時的響應速度。In the proposed technique the bemf waveform of bldcm need to be measured in advance at first, through computer simulation and frame transformation, the optimum q - axis current command is achieved. in order to minimize the torque ripple, the d and 0 - axis current command should be zero. furthermore, through reference frame transformation from dqo - axis to abc - axis, we can get the optimum current command in static abc reference frame
在這種控制方法中首先測量出電機的實際反電動勢波形,然後通過計算機擬合和坐標變換,求得產生恆定電磁轉矩所需的q軸電流,令i _ d ~ * = i _ 0 ~ * = 0 ,通過坐標變換,得到三相靜止坐標系a - b - c下的參考電流i _ a ~ * , i _ b ~ * , i _ c ~ * ,利用電流滯環控制來產生pwm信號,由於這種控制方法中電流不會突變,從而可以較好的抑制轉矩脈動。For the bldcm which has a neither sinusoidal nor trapezoidal back - emf, that is, for a general shape back - emf bldcm, this dissertation proposes a novel id = 0 vector control method. by this method, the iq for a constant torque to produce is calculated through coordinate transformation, and the reference iq is tracked by vector control in the dq0 frame
對于實際反電動勢波形既非正弦又非梯形波的無刷直流電動機,提出一種新型的任意波形反電動勢無刷直流電動機的i _ d = 0矢量控制方法,通過坐標變換浙江大學博士學位佑文摘要求解產生恆定電磁轉矩所需的q軸電流,並在dqo坐標系下通過矢量控制對q軸參考電流進行跟蹤。Based on the analysis of the control theory of the dtc of doubly fed induction machines, in this paper, two control schemes are proposed : the least mode of rotor current and the stator power factor adjustable mode. in the first control scheme, we may make the rotor voltage the same or opposite phase with the rotor current by throwing suitable rotor voltage vector
在第一種控制方案中,通過施加轉子電壓矢量,使轉子電流與轉子磁鏈垂直,轉子勵磁全靠定子電流,即可保證轉子電流和轉子電壓同相或反相,從而實現了轉子側功率因數為1 ,可減小轉子側變頻器的容量。The contributions done are as follows : according to the mathematical model of doubly fed motor and the theory of vector control, a unit power factor of rotor control scheme is proposed. in the doubly fed adjustment system, in order to control magnetic torque of motor this scheme is designed by controlling the reverse direction between rotor voltage and current to keep the vertical direction between rotor current and flux. it is known from theoretical analysis that for partly decoupling this scheme is only effective under sub - synchronization speed, but not control the system and obtain steady state since speed adjustment system ca n ' t adjust the magnitude of rotor flux under sup - synchronization
而傳統的無速度傳感器雙饋調速矢量控制系統,由於採用磁鏈定向方法,在同步速附近存在較大的工作死區,針對上述問題,本文做了如下的研究工作:本文從雙饋電機的數學模型出發,根據矢量控制的基本原理,提出了一種轉子側功率因數為1的雙饋電機矢量控制方案的設想,即在雙饋調速時採用轉子電流定向的方法,並控制外加轉子電壓與轉子電流始終反相,以保持了轉子電流與轉子磁鏈矢量垂直,通過控制轉子電流的大小來達到控制電機電磁轉矩的要求。Viewed at the surface of the model earth, the reversal of the dipole occurred when the reversed flux patches begin to dominate the original polarity on the core - mantle boundary
由模型中的地球表面看來,磁偶極的反轉是發生於地核?地函交界上反向通量斑塊開始超過原本的極性時。分享友人