無定向電流 的英文怎麼說

中文拼音 [wúdìngxiàngdiànliú]
無定向電流 英文
astatic current
  • 無 : 無Ⅰ動詞（沒有） not have; there is not; be without Ⅱ名詞1 （沒有） nothing; nil 2 （姓氏） a surn...
  • 定 : Ⅰ形容詞1 （平靜; 穩定） calm; stable 2 （已經確定的; 不改變的） fixed; settled; established Ⅱ動詞...
  • 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...
  • 流 : Ⅰ動1 （液體移動; 流動） flow 2 （移動不定） drift; move; wander 3 （流傳; 傳播） spread 4 （向壞...
  • 電流 : current; galvanic current; electric current; electricity; current flow電流保護裝置 current protec...
  1. Design engineers now selecting pmbldc motors over conventional dc or induction motor drives for the following reasons : 1 ) the absence of brushes results in an essentially maintenance free operation and eliminates the undesirable effects of commutation such as sparks, brush - loss, radio - frequency interference, etc. 2 ) the low inertia of the rotor enhances the quality of the mechanical response of the motor, shortening the acceleration and deceleration time. 3 ) utilizing rare - earth permanent magnet materials with high coercive force results in substantially higher efficiency than their counterpart with brushes of the same size. 4 ) because of the absence of commutation segments, the stator construction is simple

    現在的工程師們更為青睞永磁無刷直流電動機是因為以下幾點原因： （ 1 ）去除了電刷的永磁無刷直流電動機徹底地免除了維護而且消除了我們不希望的由於換向帶來的火花、電刷損耗以及無線電干擾等等； （ 2 ）低轉動慣量的轉子提高了電機機械響應的質量，從而縮短了電機加速和減速的時間； （ 3 ）高矯頑力稀土永磁材料的使用使得同樣尺寸的永磁無刷直流電動機比傳統的直流電動機效率高； （ 4 ）由於沒有機械換向部分定子的結構簡單了。
  2. Simultaneously, information process ability will improve intelligent device deployment inside electric power system as well. along with the development of mobile communication technique, mobile gprs ( general package radio service ) platform can realize ip connection anywhere and end to end wireless transparent transmission, so that it can provide convenient solution for electric power system existing long - distance connection of intelligent terminal with host station

    通信手段的進步可以提供更為經濟的供電與用電方的雙向交流，可以向用戶提供更多的分時定價手段。同時，信息處理能力的加強也可以在整個電力系統中促進智能化設備的推廣。移動gprs通信平臺，能夠實現ip數據端到端的無線透明傳輸，為電力系統遠程智能終端設備與主站的連接提供了方便的解決方案。
  3. Secondly, to achieve the independent regulation of active and reactive power output from the generator side which is designed for the purpose of tracing the maximum wind - energy capturing. the paper has analyzed the mathematic model of the ac excited doubly - fed machine and the stator field orientation control strategy of the motor as vscf wind power generator. thirdly, it has put forward and designed the dual pwm converter with the capacity of energy flowing bidirectional aimed at the demand of rotor energy bidirectional flow. the author constructed reliable and integrated experimental system and did a series of experimental study including no - load, cutting - in network and power generation at, below and above the synchronous speed

    論文首先分析了風機運行特性及其最佳風能利用原理，通過模擬及實驗驗證了採用直流電機的輸出特性模擬風力機的最大輸出功率曲線的可行性，並給出了模擬系統的硬體結構；然後為了實現交流勵磁發電機有功、無功功率獨立調節機理，分析了交流勵磁雙饋發電機的數學模型和在追蹤最大風能捕獲變速恆頻風力發電時必需的定子磁鏈定向矢量控制策略；針對雙饋發電機轉子能量雙向流動的要求，提出並設計了具有能量雙向流動能力的雙pwm交流勵磁用變頻器；最後為實現從理論到實踐的全面研究，研製出了一套小功率完整的雙pwm變頻器交流勵磁的雙饋風力發電機實驗系統，進行了空載、並網、同步速及上、下的發電運行等一系列的運行實驗；所完成的模擬和實驗研究均驗證了理論、模型和控制策略的正確性、可行性。
  4. The power angle characteristics are acquired and compared with the unsaturated curves. it is concluded that the stability limit of the power angle is less than 90 degree. reactive power regulating curves are calculated and compared with those curves when saturation effect is not considered, the result is that u type curves are deviated to the right

    通過對同步發電機各種運行曲線的計算，在已有文獻的基礎上更進一步分析了鐵磁材料飽和以及磁場畸變對同步發電機運行特性和參數的影響；求出了空載特性曲線和零功率負載特性曲線，在不同的電樞電流下計算得到的波梯電抗不同；求出了功角特性曲線，與不計飽和時的功角特性曲線相比較，功角穩定極限小於90 ；求出無功調節曲線，與不計飽和時相比較， u型曲線向右偏移。
  5. The reactive power optimization compensation is to find the suitable compensation place and the best compensation capacitance by adjusting the generator bus voltages, transform taps and reactive compensation capacities in the condition of satisfying power load requirement, which can guarantee the secure and high quality power for consumers. the improved genetic algorithm is applied in this thesis according to the features of reactive power optimization of high voltage transmission bus, which are the non - linear problems with multi - variables and multi - restrictions

    電網無功優化補償是在有功潮流調度給定的情況下，以負荷節點電壓和線路輸送無功功率作為狀態變量，運用優化演算法，調節發電機節點電壓、變壓器可調分接頭和無功補償裝置，在滿足電力負荷的要求下，尋求合理的無功補償點和最佳補償容量，保證電網能夠安全、優質地向用戶供電。
  6. Specific issues examined are : compensation for the variation of the stator resistance, the offset error of the dc bus voltage, the voltage error generated by the forward voltage drop the dead time of the switches, improvement of the steady state performance, and the speed sensorless control for the pmsm dtc drive system are of major concern in this thesis

    定子電阻變化，直流母線電壓漂移，開關器件反向相電壓降、逆變器死區時間引起的電壓誤差的補償，提高系統穩態運行性能以及永磁同步電機直接轉矩控制的無速度傳感器運行方案等問題都是本文研究的重點。轉矩的快速響應是直接轉矩控制演算法的一個卓越的性能。
  7. Adopting rotor field - oriented vector control methods, through which make the stator and the rotor magnetmotive forces can be kept orthogonal all along during operation of the bldcm, combining hysteresis current modulation ' s current control advantage and space voltage vector modulation ' s torque ripple attenuation advantage, then designing a sort of bldcm hysteresis current svpwm control method

    摘要研究採用轉子磁場定向的矢量控制方法使無刷直流電動機定、轉子磁勢矢量始終保持正交，結合滯環調制電流控制和空間電壓矢量調制，設計了無刷直流電動機滯環電流svpwm控制方案。
  8. This strategy has many advantages : solving the problems that the system is unsteady under super - synchronization ; improving power factor of stator ( it is unity relative to that of rotor ) ; no rotor position sensor and no initial position measurement, easily building up doubly fed speed adjustment system with speed sensorless because adjusting speed is taken in the rotor coordinate and rotor current vector fixing is implemented

    該方案由於引入了定子電流勵磁分量的閉環控制，使系統同時具有轉速和勵磁調節兩個調節通道，具有如下優點：一、解決了超同步工作工況不穩定的問題；二、提高了定子側的功率因數（與轉子側功率因數為1相比） 。三、由於速度調節在轉子坐標系下進行，並以轉子電流矢量定向，所以無須轉子位置傳感器，也不用檢測初始位置，易於組成無速度傳感器雙饋調速系統。
  9. For the first time, the solenoid collecting magnetic field optical transducing principle is presented in this paper, and it is proved that the way to measure current by polarized light encircling conductor and that by polarized light threading solenoid axes are equivalent

    為了解決aoct的長期運行穩定性問題，首次提出了「螺線管聚磁光學傳感原理」 ，證明了偏振光圍繞著無限長通電導體測量電流與偏振光通過通電螺線管的軸向方向測量電流，在光學傳感測量電流的意義上是等價的。
  10. And the converter will work on the strategy of vector control with the definitive direction of the stators magnetic field. also, the thesis develops the algorithm to corroborate the magnetic field ' s direction by the state ' s current and voltage. to validate the theory analysis of bdfg

    根據理論分析和模擬的結果，本文提出級聯式無刷雙饋發電機的控制策略是基於定子磁鏈定向的矢量控制方法，並推導了用定子側電壓電流量來確定定子磁鏈方向的演算法，繪制了相應的閉環控制框圖。
  11. 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。
  12. 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。
  13. The prototype test results indicate : voltage mode and current mode ac - ac mode ac / ac converters with high frequency link have the advantages such as high frequency electrical isolation. simple topology, two - stage power conversions, high power density, bidirectional power flow, good line current waveform, no audio noise, high converting efficiency, and high input power factor etc. this kind of converter lay the key technical foundation on new type regulated sinusoidal ac power supply, electronic transformer, ac regulator, and wave converter etc

    試驗表明，這類變換器具有高頻電氣隔離、電路拓撲簡潔、兩級功率變換（ lfac hfac lfac ） 、功率密度高、雙向功率流、無音頻噪音、變換效率高、網側功率因數高等優點。為新一代正弦交流穩壓器、電子變壓器、交流調壓器、同頻波形變換器的實現奠定了關鍵技術基礎。
  14. Consumers successively plunged a large number of silicon controlled commuted devices ( such as steel rolling 、 electrized locomotive 、 aluminium electrolysed devices etc ) and smelting devices to improve their produced efficiency or to save energy. on the one hand it is good for consumers, on the other hand it will arouse the fluctuation of voltage and frequency and it will result in the collision of the active and reactance capacity. meanwhile these nonlinear loads bring much harmonic into the electric network which deteriorate the quality of power supply and hazard the online device enormously

    用電部門為了提高生產效益、節約能源，在大電網中相繼出現了大量的可控硅整流裝置（如軋鋼、電氣化機車、鋁加工電解設備等）以及冶煉設備，這些設備的投入使用對節能有一定好處，但給電網造成有、無功沖擊，引起電壓和頻率的波動，同時，這些非線性負荷向電網注入大量諧波，大大惡化了供電系統的電能質量，給用電設備帶來了極大的危害。
  15. However, these converters become more complicate. phase - shift bi - directional dc - dc converter is attractive since it operates with fixed frequency, has small voltage and current stress and can realize zvs without auxiliary switches

    相移控制雙向dc - dc功率變換器因具有功率器件電壓，電流應力小，定頻工作和無須增加輔助器件即可實現功率器件的零電壓開關條件等優點而受到關注。
  16. The simulation results showed that there are some differences between the waveforms of currents. by comparing the average dynamic currents, these test pairs can detect some faults

    模擬結果表明，故障電路和無故障電路的動態電流產生了一定的差別，通過比較兩者的平均動態電流，這些測試向量對能有效的檢測某些故障。
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