逆步變量 的英文怎麼說

中文拼音 [nìbùbiànliáng]
逆步變量 英文
contragradient variables
  • 逆 : Ⅰ形容詞1 （方向相反） contrary; counter 2 [數學] inverse; converse Ⅱ動詞1 （抵觸; 不順從） go aga...
  • 步 : Ⅰ名詞1 （步度; 腳步） pace; step 2 （階段） stage; step 3 （地步; 境地） condition; situation; st...
  • 量 : 量動1. （度量） measure 2. （估量） estimate; size up
  1. According to the research of physiological and biochemical indicators or index, components of soluble proteins, substrate protein of phosphorylation and the activity of protein kinase in low - temperature stress in the leaves of brassica oleracea l., we tried to find the law of the physiological and biochemical response of brassica oleracea l. leaf to low temperature. at the same time, discussion on the signal transduction can also provide further evidences for revealing the mechanism of low - temperature stress. the results are showed as follows : malondialdehyde ( mda ), superoxide dismutase ( sod ), ascorbate peroxidase ( asp ) and peroxidase ( pod ) activities were changed greatly after 0 ~ 30min ' s treating with low temperature

    本文以甘藍葉片為材料，通過對低溫5脅迫下甘藍生理生化指標、可溶性蛋白組分以及磷酸化底物蛋白、蛋白激酶活性的研究，以期找出甘藍葉片對低溫脅迫的生理生化響應規律，為甘藍露地越冬栽培防範寒害提供理論指導，同時對低溫脅迫下甘藍逆境信號傳導進行了探討，從而為徹底弄清低溫脅迫機理提供進一步的證據，研究的主要結果如下：丙二醛含量（ mda ） 、超氧化物歧化酶（ sod ） 、抗壞血酸過氧化物酶（ asp ）和過氧化物酶（ pod ）活性在低溫處理0 30min發生顯著變化，低溫處理3min后，甘藍葉片內mda含量基本沒有變化，處理5min時出現第一個峰值，達到對照的104 . 10 ， 10min出現低谷，僅為對照的86 . 27 ，隨后再次上升， 30min時超過第一峰值，為對照的113 . 93 。
  2. In this paper, through treating lines reciprocal transformation to a matrix, cogradiently reach the eigenvalue and eigenvector of a matrix, to solve the question treat a eigenvalue under without parameters, and given some advanced theorems

    摘要通過對矩陣進行行列互逆變換，同步求出矩陣特徵值及特徵向量，解決了不帶參數求特徵值問題，並給出一些新定理。
  3. 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。
  4. The second chapter simply introduces the development of alternate asynchronous inverter technology and retrospects some types of energy - saving systems for hydraulic elevators. then the working principles of the project are discussed and analyzed at four different working status, i. e. light load upwards, heavy load upwards, light load downwards and heavy load downwards. and the chapter focus on the introduction of structure design of pump station, calculation and type selection of pump / motor reversible units, research on oil leakage principles of accumulator circuit, design of accumulator - pump / motor pressure - energy transformer and integrated valve blocks, etc. the last but not the least, the electrical wiring of vector inverter control cabin and design of computer control and data acquisition system are introduced

    論文第二章首先簡單介紹了交流異步電動機變頻調速技術的發展概況，在回顧電梯液壓控制系統節能技術的基礎上，介紹了本課題研製的「採用蓄能器的液壓電梯變頻節能控制系統研究」的基本原理，分析了動力系統在電梯轎廂輕載上下行、重載上下行等四種典型工況下的基本工作狀態和工作方式；詳細地介紹了本課題節能系統液壓動力泵站的結構設計和參數設計，重點研究了液壓動力泵站的結構設計、液壓泵馬達可逆性問題及其選型設計計算、蓄能器迴路泄漏油損失機理的研究及其補償裝置的設計、蓄能器-泵馬達壓力能量轉換裝置的設計、多功能集成控制閥組的設計等內容；最後簡單介紹了本課題矢量控制變頻控制櫃的外部附件電氣接線、計算機控制及數據採集系統的硬體設計等內容。
  5. 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。
  6. So the only way for agricultural development is structural adjustment. under the theory of structure economy growing, the theory duality economy structure and the law of the industry structure evolution mainly, this paper, firstly, analyzes the characteristics of evolution and current situation of hubei province ' s agricultural industry structure including the evolving better, singleness, facing crisis, by stage, lack of power, crop ' s development setting back the evolution, asymmetry - structure between the production value and output, the similar structure with the whole nation and the peripheral provinces, and so on

    本研究在結構主義經濟增長理論、產業結構演進規律和二元經濟結構論等經濟學理論的基礎上，首先通過產值比重結構對比、產業結構變動度、產業結構波動度、產業結構相似度和偏離系數等指標和方法，從多方面分析了改革開放以來湖北省農業產業結構演進與現狀特徵：農業產業結構逐步優化，但結構單一，面臨危機；農業產業結構呈階段性演進；農業產業結構演進缺乏動力；種植業成為湖北省農業產業結構優化障礙；農業產值與產量結構不對稱，出現逆向變化；農業產業結構與周邊省份趨同等。
  7. In mmse based detection algorithms it ’ s inevitable to do the matrix inversion operation, and we have found by analysis that such matrices are all positive definition hermite matrices. so, in chapter three, by renumbers the looped variables we induce a new matrix inversion algorithm and based on the symmetry of the data we further

    由於基於mmse的檢測演算法中會不可避免地遇到矩陣求逆運算，經過分析發現此類矩陣均為正定hermite矩陣，根據此類矩陣的特點引入了變量循環重新編號法求逆演算法，並且根據運算過程中數據的對稱性提出了進一步的簡化方案。
  8. Based on x - filtered lms algorithm and - filtered lms algorithm adaptive inverse control, we use a new variable step size lms algorithm. adding little computation, variable step size lms algorithm can result in fast convergence speed and low residual error simultaneously. the adaptive feedback control can counteract the beginning error of the system

    在原來的x -濾波lms演算法自適應逆控制和-濾波lms演算法自適應逆控制方法的基礎上，引入了新的變步長lms演算法，在計算量增加不多的前提下，能同時獲得較快的收斂速度和較小的穩態誤差；引入自適應的反饋補償控制克服了被控系統的直流零頻漂移，使控制系統在初開始工作階段快速收斂；還引入自適應擾動消除器，它能最大限度的消除擾動。
  9. Researching on the technology if reverse order is to study strains if pits, structural systems if basement, environmental surwey and underpinnings. on account of emphasizing developing methods if checking strength if pick - ets, modemizing machenes of excavation and studying methods of underpinning is put forward and is a way if controlling the quality of pickets in sites, which leads an active effect ; synthetic application if rankintheory, spatial and time effect theory to excavation tl aanalyze the state of soil force and strain is brought forward and the time effect should be considered in the zone of clay, the formation and development of soil plasticity are analyzed and the most dangerous zone to decide how to excavate and where to begin is found ; analyzing the cause of picket settlement during reverse order and the differential settlement and discussing hlw to solute it. duringh the temporary survey and the environmental warship, bringing rorward the theory of environmental vibration and analyzing the state of soil force and probability of losing stabilization of soil under the effect of environmental vibration ; analyzing the state offeree in underground concrete wall by the method of mathematics and pointing out the place of the maximum force and deformation. based on systematic illustrating the reverse order, problems about application and development of reverse order and suggestions also are expressed

    鑒于國內外的研究把重點放在大力發展工程樁的實驗室承載力監測方法與設備、如何使土方開挖機械現代化及對周圍建築的臨測方法上，本文提出了現場利用聲波層析成像技術監測鋼砼樁內部質量的方法與程序，並得出了聲波層析成像技術是砼樁的動態質量檢測的有效手段，這對指導施有積極、現實意義；提出了綜合運用朗肯土壓力理論、基坑空間和時間效應影響理論來分析逆作法施工過程中基坑邊坡土體應力及應變的變化情況，指出粘土地區也應考慮時間效應，並且進一步分析了基坑邊坡土體的塑性區形成和發展，找出邊坡最不利的區域，以確定地下室土體的挖掘的方式和順序，指出憑主觀臆斷與經驗來施工是不可取的；在分析、經較逆作法與大開挖順作法的地下室結構體系受力情況及施工順序的不同，提出了節點處理技術；分析了逆作法施工期間樁的沉降變化原因及由此而產生的差異，並探討了解決的方法；本文還提出了環境振動對土體邊坡穩定產生影響的觀點，並分析了在環境振動影響下，土體的應力狀態及土休失穩破壞概率，並且還運用彈性力學知識和數學分析的方法定量地分析了地下混凝土墻受力狀態，指出了被監測墻體的最大應力、應變位置。
  10. Some research about sensorless control of induction motors in recent years has been introduced in chapter one. in chapter two, a field - oriented control system with current regulator and voltage source inverter ( vsi ) is presented firstly, which is proved in theory that the voltage feed - forward decoupler can be omitted, the good decoupled control properties of flux current and torque current is also validated by experiments with speed - sensor based on f240dsp real system

    論文第二章從異步電機的基本數學模型入手，介紹了一種基於轉子磁場定向的帶電流內環控制的電壓型逆變器輸出閉環矢量控制結構，在理論上證明了該模型可省略電壓前饋解耦環節，採用f240dsp晶元構建的帶速度傳感器實驗系統驗證了其定子電流勵磁分量和轉矩分量有良好的解耦控制特性。
  11. In dtc system, the concept of space vector is introduced to analyze and control the ac motor, the electromagnetic torque and flux are calculated and controlled in the stationary coordinate, and the optimal pwm gating signals are generated to control the inverter to acquire high dynamic torque according to the output of the bang - bang regulators

    直接轉矩控制採用空間矢量的概念來分析三相異步交流電動機的數學模型和各物理量，直接在靜止坐標系下計算與控制交流電動機轉矩和磁鏈，藉助于離散的兩點式調節產生pwm信號，直接對逆變器的開關狀態進行最佳控制，以獲得轉矩的高動態性能。
  12. This paper study a two - phase inverter - fed induction - motor drive, which can be widely used for low - power, variable speed drive system. the study has completer 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 singlechip controller, power drive device, inverter - fed device, a low power tow phase induction motor and safeguard circuit

    本文研究了一種新型電壓空間矢量控制兩相逆變器?異步電動機的變頻調速系統，該系統可以廣泛應用於小功率、寬調速運行的場合。本項研究完成兩相逆變器的設計，並組成了試驗用的兩相逆變器?異步電動機系統。系統是一個轉速開環的變頻調速系統，由單片機機控制電路、功率驅動電路、逆變器主電路、保護電路組成。
  13. Recurring to resynchronization marker, data partitioning and rvlc, video files with errors are dealt with. the article codes and decodes video source files with errors, computing every algorithm ' s psnr, comparing video pictures " subjective and objective quality

    運用重同步標志（ resyncmarker ） 、數據分離（ datapartitioning ）和可逆變長編碼（ rvlc ）對含錯的視頻文件分別做錯誤處理。以mpeg - 4錯誤恢復方法對糟糕視頻源文件編碼、解碼，計算該演算法的psnr ，比較視頻幀的主客觀質量。
  14. The asynchronous motor is widely used for its simple construction, ruggedness, high working reliability, relatively low cost, and high environmental adaptability. it is suit for the direction of high voltage, high speed and large capacity. vector control is its ideal speed modulation method. the harmonics of three - level inverter are less than the traditional two - level inverter ’ s, and it is convenient to realize high sinusoidal voltage output. the maximum voltage strength which each electric component bears is small, and it is easy for three - level inverter to realize large capacity. the research on the asynchronous motor vector control based on the three - level inverter is one novel work

    異步電機結構簡單、堅固耐用、運行可靠、成本低、環境適應性強，容易向高壓高速和大容量方向發展，獲得了廣泛應用，矢量控制為其理想的調速方法;三電平逆變器輸出端諧波少，有利於實現輸出電壓的正弦化，且單個開關管承受的最大電壓小，適合向高壓大容量方向發展。對基於三電平逆變器的異步電機調速系統開展矢量控制研究，是一件有意義的工作。
  15. 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。
  16. This paper studies on used the ac servo system based on ti dsp ( lf2407a ) and the foc and digital signal processing thorem, achieves following results : algorithm. we employ svpwm ( space voltage pwm ) algorithm, improve the efficiency of the electric source, and decrease the harmonious elements. we build the mathematic model of the system and simulate it on matlab platform, dsigne segmented pid regulator to adapt variable speed and widen the speed range. measurement. the velocity and electric current measuring, we adopt multi - sampling - rate and digital filter principles. as more improvements we make, the whole system gets a good results. pc control. the complete controlling system can be controlled remotely. so we develop the pc controlling program.

    採用磁場定向脈寬調制演算法，提高了電源利用率，降低了逆變電壓的諧波，改善了電機的運行特性，降低了對電網的污染；在matlab平臺上建立了交流永磁同步伺服電機和電壓空間矢量脈寬調制控制系統的數學模型，在模擬的基礎上，對傳統pid調節器進行了改進，提出轉速調節器和電流調節器採用分段pid結構，根據給定轉速所處的區間，自動選擇相應pid調節器的參數，拓寬了調速范圍，提高了控制精度。
  17. The constitution, interface and control principle of main circuit, rectifier control module, inverter control module, generator ' s rotor speed and rotor position measuring module, information exchange module are discussed. specially, the methods of implementing signals level match in multi - voltage system, synchronizing with pc in parameters measurement and measuring rotor speed and rotor position with high precision are explained in detail

    文中討論了主電路、整流器控制模塊、逆變器控制模塊、電機轉速和轉子位置測量模塊以及信息交換模塊的組成、介面方法和控制原理，詳細說明了系統中實現不同電壓等級間信號電平匹配的方法、系統與上位機進行同步參數測量的方法以及實現高精度電機轉速和轉子位置測量的方法。
  18. The power circuit of the system adopts the voltage frequency conversion structure of ac - dc - ac, and is composed of the commutation circuit, filter circuit and intelligence power module ( pm15rsh120 ). control circuit takes the dsp chip tms320lf2407 as core, including the pwm signal occurrence circuit, detect circuit of stator current and direct current voltage of generatrix, drive circuit of intelligence power module, detect circuit of speed, protect circuit of system etc. all of this builds the full digital vector control system of asynchronous motor

    該系統的功率電路採用電壓型的交-直-交變壓變頻結構，由整流電路、濾波電路及智能功率模塊ipm （ pm15rsh120 ）逆變電路構成;控制電路以dsp晶元tms320lf2407為核心，加上pwm信號發生電路、定子電流檢測電路、直流母線電壓檢測電路、智能功率模塊驅動電路、速度檢測電路、系統保護電路等，構成了功能齊全的異步電機全數字化矢量控制系統。
  19. When the motorcycle is braking or slowing down, the kinetic and / or potential energy is fed back to the battery, so the running distance can be extended and the energy efficiency is improved. an asynchronous motor is employed in this new system which can overcome the traditional dc drive system bugs and to reduce the cost and maintenance. in addition, the switches of dc / dc converter switch under zero current and zero voltage conditions, which can also reduce the switch losses, electro magnetic interference ( emi ) and prolong its life

    該系統在功能上實現了車輛剎車減速或下坡制動時能量的回饋，達到節能、提高能量使用效率和增加車輛行駛距離的目的；採用交流異步電機，克服了傳統直流驅動系統的諸多缺陷，降低了成本，減少了維護；採用zczvs技術，降低了電磁干擾和損耗，提高了效率；另外，在逆變主電路中採用ipm模塊，簡化了系統結構，節約了空間，提高了整個系統的可靠性和經濟性。
  20. The simulation model of pmsm close - loop control system is presented based on pwm inverter model and switching vector table model set up by the author and pmsm model in matlab. the model is proved correct from the simulation result

    然後在自行構造逆變器，開關電壓矢量表等模塊的基礎上，利用matlab中的永磁同步電機模型，實現了永磁同步電機閉環控制系統的模擬模型，模擬結果驗證了方案的正確性。
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