通量逆轉 的英文怎麼說
中文拼音 [tōngliángnìzhuǎn]
通量逆轉
英文
flux reversal-
Because along with the liberalization of china ’ s capital account, once the economic developing speed slows down, capital account and current account ’ s surpluses reverse to deficits, the appreciation expect of renminbi will be changed. at the same time, the high quota savings in china ’ s banks will also bring us inflation pressure, inapparent currency substitution may be turn into visible currency substitution. also, the great deal of currency substitution inclining may convert into real currency substitution because of the vulnerable financial system
但另一方面，它又離我們那麼近，因為隨著中國資本賬戶開放的逐漸深入，一旦我國經濟不能保持高速發展，資本賬戶和經常賬戶雙順差現象出現逆轉，人民幣升值的預期將被改變，而我國高額的人民幣儲蓄也將給我國帶來通脹壓力，隱性的貨幣替代將有轉為顯性貨幣替代的可能，由於金融體系脆弱性所造成的大量貨幣替代傾向也很可能轉化為真實的貨幣替代。The algorithm of svpwm that is adopted by the system implements motor speed - regulation by control of magnitude and phase of motor flux. it can generate less harmonics in the output current of power inverter and less losses of ac motor, reduce pulsant component in output torque and raise availability of dc supply voltage
系統採用的svpwm演算法通過對空間磁鏈矢量幅值和相位的控制來調節電機轉速，減少了逆變器輸出電流的諧波，降低了脈動轉矩，提高了電壓的利用率。Histochemical staining in tl transgenic tobaccos showed that sigp1 promoter was not only organ - specific ( especially expressed in leaves and guard cells ), but also highly inducible by multi stress treatment such as drought, aba, high salinity and low temperature. quantitative analysis showed that gus activity in roots was very weak and no great changes were observed after treatment
通過對t1代轉基因苗的組織化學定位表明，該啟動子驅動的gus基因在逆境（如乾旱、 aba 、高鹽和冷）脅迫的葉片中表達，根中不表達，且老葉中的表達量高於幼葉中的表達量，說明其表達受發育階段的調控。The air thermal cnergy water heater creates the new generation hot water cquipments. it makes use of the negative card promise successfully, drieing a hot pump with the elcctrie power. equiping through a hot pump medium of compesing parts evaporate a machine. hot pump, congealed machine and inflate valve, urge the work quality completes evaporationt absorb calories within air continuously compress compress congealed reduce expenses evaporate of the thermody name energy cirenlation proess, transfer the calories in the environment to the water thus in, transfer the in great quantities free calories in the air to the life to use a water in
空氣節能熱水器是創新一代熱水設備，它成功地運用逆卡諾原理，用電能驅動熱泵，通過熱泵裝置中的構成部件-蒸發器，熱泵，冷凝器和膨脹閥，促使工質不斷完成蒸發（吸收空氣中的熱量）壓縮冷凝節流蒸發的熱力循環過程，從而環境的熱量轉移到水中，將空氣中大量免費的熱量轉移到生活中水中The study has completed the design of two - phase inverter and made up of the two - phase inverter - motor system for experimental use it is a variable frequency adjustable speed system with a open - loop control of rotational speed, which consists of voltage - controlled oscillator circulating assign device inverter circuit and two - phase induction motor a accurate mathematical model is set based on the whole system, and simulator program of dynamic and steady condition is established, which is used to calculate the dynamic and steady performance by kron and symmetrical coordinate converter by simulator calculation and experimental research with specific parameter of the system, a comparison is made between predicted and experimental characteristics, experimental measurements are shown to compare closely with corresponding theoretical result it is compared with some variable frequency adjus table speed system comprising inverter and single - phase induction motor from the system efficiency torque pulsation and the effect of two - phase inverter capacitance based on the conclusion, harmonic cancellation pulse width modulation control of a two - phase inverter - fed induction - motor drive system is researched, which cancelled the low harmonic and improve the system performance
通過對電機的kron變換和對稱分量變換，建立了系統較精確的數學模型，編制了系統動態及穩態運行的模擬計算程序分別計算系統的動態和穩態性能。通過對系統的具體參數進行了模擬運算和實驗研究，實驗和模擬結果進行比較，說明實驗和理論較為一致，並從系統效率、轉矩脈動及兩相逆變器電容的影響等方面與各種逆變器和單相異步電動機組成的變頻調速系統加以比較。在此基礎上，對兩相逆變器供電-異步電動機系統使用諧波抑制pwm控制進行了研究，由於減少了低次諧波，改善了系統性能。The stability of electric power system has been being focused for a long time toprevent a power system from losing synchronism after sudden fault ， researchers have done much work and got many accomplishments this paper applied the direct feedback linearization ( dfl ) technique on the power system ， a strong nonlinear system simulation results by matlab proved this method efficiency main works and results are as follows ： this paper compared some existing methods in excitation control ， fast valve control and coordinated control respectively, analyzed the developments and actuality of nonlinear control research in brief, illustrated why ransient stability could be greatly improved by using the fast valve control in chapter 3 ， indicated the importance of coordinated control farther this paper introduced the inverse system theory, based on which ， discussed the dfl theory, pointed out which had consistency with the inverse theory, expanded the dfl theory combined the idiographic model equations ， made which adapt to the model of a single machine - infinite bus power system this paper referenced abundance articles and educed a set of equations ， which could describe the dynamical process of excitation and fast valve control for synchronous generators in the equations ， there were several very important parameters of power system - - rotor angle ( ) ， rotor speed ( ) ， generator q axis voltage ( eq ) ， transient voltage ( e ' q ) ， active power ( pe ) ， mechanical input power ( pm ) ， valve opening ( ) ， generator terminal voltage ( vt ) ， based on the model ， nonlinear coordinated controller and terminal voltage optimal controller have been designed by using the expanded dfl theory and lq optimal control theory the simulation results showed that the controller could keep power system transiently stable under the effects of a symmetrical 3 - phase short circuit fault ， which achieved better postfault regulation compared with another two routine methods ， one is the proportion excitation controller and proportion fast valve controller, the other is the proportion excitation controller and the optimal fast valve controller, which could exert good performance when met 1ittle disturbance either
在介紹逆系統理論的基礎上，詳細介紹了dfl理論，通過比較闡明了dfl理論其本質是逆系統方法的一類，並結合具體課題推導出的模型方程將dfl理論進行了擴展，使之適應于電力系統這個強非線性對象。通過參考大量的書籍文獻推導出一套實用的可將大型汽輪發電機勵磁與汽門綜合起來進行控制的模型方程，此模型方程涵蓋了電力系統中特別引人注目的幾個量- -轉子角、轉子轉速、發電機q軸電勢eq 、暫態電勢e ' q 、有功功率pe 、機械功率pm 、汽門開度、機端電壓vt ，在此基礎上建立了實用的電力系統簡化的數學模型，並將擴展的dfl理論應用於此模型系統，結合線性二次型最優控制理論設計出大型汽輪發電機的非線性綜合控制器及機端電壓最優控制器，通過模擬實驗與採用常規的按電壓偏差進行調節的比例式勵磁控制器+汽門比例控制及採用常規的按電壓偏差進行調節的比例式勵磁調節器和基於二次型性能指標設計的最優快控汽門（考慮發電機的飽和因素）進行了對比，證實了採用此種控制器可以有效地提高電力系統的暫態穩定性，並且在電力系統遭受小干擾時同樣具有良好的調節性能。There are five parts are as follows : in part one, the concept of switching function is introduced first to establish the nonlinear mathematical model of the induction motor variable frequency speed adjustment system which is fed by a sine pulse width modulated ( spwm ) inverter and takes the effect of the main magnetic circuit saturation into consideration, then the low frequency oscillation of the system is simulated according to the model. next, from the view point of energy conversion of the inverter - induction system, a criterion for the low frequency oscillation is proposed to determine whether the system is in low frequency oscillation which is judged by whether the interval of the negative current component of the inverter input current is more than 1 / fc ( fc is the carrier wave frequency of the inverter ) or not
首先引入開關函數概念，建立了正弦脈寬調制（ spwm ）逆變器供電異步電動機，考慮主磁路飽和時的變頻調速系統整體數學模型，模擬系統的低頻振蕩；其次從逆變器-異步電動機系統能量轉換角度出發，提出通過檢測逆變器輸入電流中負電流的間隔時間是否大於1 / f _ c （ f _ c為逆變器載波頻率）來判定系統是否出現低頻振蕩；最後的實驗結果驗證了系統低頻振蕩建模和判據的實用性和正確性。After the analysis of the state of converter switches, the voltage space vector is received. on the basis of hexagon stator flux trace method of traditional direct torque control, by changing the regulation of stator flux, hexagon and approximate round trace of stator flux can be got when using different voltage space vector. the fast regulation is realized when three - value regulator is used to adjust torque
通過對逆變器開關狀態的分析進而得到電壓空間矢量，並且論述了電壓空間矢量與轉矩和磁鏈之間的關系，使用兩點式調節方法對定子磁鏈進行調節，實現六邊形磁鏈軌跡和圓形軌跡方案，對轉矩採用三值調節器進行調節，以實現轉矩的快速調節。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。The operating principles of svpwm and associated control algorithms are also covered in the paper. by using svpwm to control the magnitude and phase angles of the spatial voltage vector, the speed control of the drive system in this paper can reduce the output of current harmonics, lower the torque ripple, and improve the energy efficiency
本文還對svpwm的工作原理和控制演算法進行了研究，控制系統採用svpwm演算法，通過對空間電壓矢量的幅值和相位的控制來調節電機轉速，減少了逆變器輸出電流的諧波，降低了脈動轉矩，提高了電壓的利用率。First we collect signals by shake and infrared temperature sensor, transfer them to computer by a / d instrument, dispel zero excursion of sensor and in - linearity of a / d transformation, save them in the form of data file. then transfer them to matlab, analyze and dispose by wavelet function and toolbox. by lot of experiments and data analysis we find distinct change of the character in different fault states
然後，我們在現場對砂光機進行實驗，利用振動及紅外線溫度傳感器現場實時採集信號，通過a / d采樣卡送入計算機中，採用逆向建模的新方法來消除傳感器零漂及a / d轉換的非線性，再以數據文件形式保存，然後在matlab中調用數據文件，應用小波函數及工具箱對其進行處理分析，經過大量的實驗及數據分析發現在不同的故障狀態下，特徵量有明顯變化。The performance of the electric vehicle is improved greatly in which the harmonic wave of output voltage, power loss and torque pulsation of the system are decreased by controlling the switch angles
它運用規則采樣法產生正弦脈寬調制波，通過開關角的控制抑制逆變器輸出電壓中的諧波分量，降低了電動機的損耗和轉矩脈動，使電動車的運行性能得到了較大改善。This paper make a study of controller on permanent magnetsyn - chronous motor. the permanent magnetsyn - chronous motor has many virtue such as simply structure and simle solidity etc. with this excellence. it has more and more uses in industry and agriculture. the idea of this paper is to control permanent magnetsyn - chronous motor system through vector control. to solve the problem of pid regulator, we use the fuzzy control and self adaptive pid
本文設計的思路是採用轉子磁通定向的矢量控制技術，主電路採用spwm和交-直-交電壓型逆變器，其中spwm採用sa4828晶元直接產生，在控制器的實現方面，採用了tms320lf2407型dsp晶元作為主控板cpu ，實現了電流、轉速雙閉環的控制系統。In the design of real - time control system, the paper takes three - phase full - bridge mosfet inverter as the real - time control main circuit, and adopts a control scheme with 120 ? switching mode combined with half - bridge pulse width modulation ( pwm ), which would avoid straightthrough short of a certain bridge. phase current is detected by single current sensor ; three - phase position signals generated by position sensors could not only supply commutation information for inverter, but also be used for speed detecting based on signals " period measurement, which makes the speed sensor unnecessary. the whole control system adopts speed and current dual closed - loop control strategy in order to construct a high performance rare - earth permanent magnetic brushless dc motor ( repm bldcm ) full - digital real - time control system
在實時控制系統的設計中，本文以三相全橋mosfet逆變電路作為實時控制主電路，採用120導通方式結合半橋pwm調制的控制方案，從而有效地避免了橋臂的直通短路；本文用單電流傳感器實現對相電流的檢測，來自位置傳感器的三相位置信號不僅為逆變電路提供換相信息，而且也用於基於信號周期測量的轉速檢測，這樣就省去了速度傳感器；系統採用的是速度、電流雙閉環控制策略，力求構建高性能的稀土永磁無刷直流電動機全數字實時控制系統。The mathematical model of working process is built, and the theoretical analysis is accomplished, too. from the viewpoint of energy building and transform, another new method, named as additional resonant starting way, is presented. the principle of working and the structure of the circuit are described in detail
通過分析負載變化對串並聯逆變器啟動的影響，在預充初始能量研究的基礎上，從能量補償和能量轉換的觀點，提出了兩種新的啟動方法：負載充磁啟動方法和附加振蕩啟動方法。However, there is no concept directly corresponding to objects in non object - oriented systems. a lot of object - extraction approaches for extracting objects from legacy systems into object - oriented systems. the paper did a lot of in - depth research about object - extracting approach on module features
由於在非面向對象系統中沒有與對象直接對應的概念，因此目前提出了大量的對象抽取方法，通過逆向工程思維，將非面向對象系統轉換為面向對象系統。In dtc system, the concept of space vector is introduced to analyze and control the ac motor, the electromagnetic torque and flux are caculated and controlled in the stator reference frame, and the optimal pwm gating signas are generated to control the inverter according to the output of the bang - bang regulator. in this paper, the dtc system is designed based on dsp. a speed estimation method is derived detailedly and the sensorless speed close - loop control is conducted. in this system, there are some problems, such as flux drift and torque ripple. to resolve these problem, a modified flux caculation method and some measures such as speed lpf, torque slide filtering are adopted. the system performance is enhanced by these mersures
直接轉矩控制採用空間矢量的概念來分析異步電機的數學模型和控制其各物理量，直接在定子坐標系中計算和控制轉矩和磁通，藉助于離散的兩點式調節（ bang - bang控制）產生pwm信號，直接對逆變器的開關狀態進行優化控制，以獲得轉矩的高動態性能。本文採用dsp設計了直接轉矩控制系統，詳細推導了速度估計方法，進行了無速度傳感器的速度閉環控制。分享友人