逆轉變換 的英文怎麼說
中文拼音 [nìzhuǎnbiànhuàn]
逆轉變換
英文
reversal shift-
The equations of motion governing the axisymmetric elastic deformation of finite orthotropic cylindrical shells, involving the effect of transverse shear and rotational inertia, are derived. by applying the reverberation method, the displacement and the resultant forces of the shell in the phase space are expressed. then the transient waves in the finite orthotropic cylindrical shell subjected to the axisymmetric impact are obtained by using inverse laplace transforms. furthermore, the transient solutions are decomposed to the generalized ray integrals and computed numerically
分析了計及剪切變形和轉動慣性的有限長正交異性圓柱殼中彈性瞬態波的傳播問題,採用回傳矩陣法,在相空間中給出了位移和內力的表達式。再利用laplace逆變換,得到正交異性圓柱殼受軸對稱沖擊作用時彈性瞬態波解,然後將其分解為若干廣義射線積分之和,並用數值方法求解之。The ultrasonic motor is a kind of direct driver which is uses the converse piezoelectric effect of the piezoelectricity ceramics, by using transformation and the coupling of each kind of expansion and contraction vibration pattern enlarging the material microscopic distortion by resonate effect and transforming it to macroscopic movement of the rotor or the slide by the friction coupling
超聲波馬達是一種利用壓電陶瓷的逆壓電效應,通過各種伸縮振動模式的轉換與耦合,將材料的微觀變形通過共振放大和摩擦耦合轉換成轉子或者滑塊宏觀運動的直接驅動器。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 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。Currently warsony corporation has multiple lighting source and lighting systematic product, which provides modern life with the most advanced power reduction and environmental protection technology, and pioneering environmental protection lighting fashion all over china. main products include solar energy plate with high conversion ratio, high - efficient controller and commutator etc
公司的主要產品有:高轉換率太陽能板膠體蓄電池高效控制器逆變器大功率led等,產品運用廣泛,已普遍用於太陽能戶外照明太陽能廣告箱牌太陽能蓄電房子太陽能交通信號及監控系統及各類太陽能小禮品等。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。Development of research on the coupled catalytic conversion of light alkanes and carbon dioxide
低碳烷烴催化脫氫與逆水煤氣變換偶合轉化的研究進展The ne - strike compressional faults are not intersected with the ew ma in fault zone, but a kind of transform structure resulted from its right lateral strike slip, and one of the typical example is the mesozoic thrust systerm in the northeast side of the main fault in western liaoning
在青龍斷裂帶兩側,分佈有許多北東向壓性斷層,它們與東西向主斷裂帶不是簡單的切割關系,而是東西向主斷裂帶右行走滑活動中的分支斷裂,位於青龍斷裂帶北東側的遼西地區中生代逆沖推覆構造,也是青龍斷裂帶在右行走滑作用下,因構造方向的改變發生構造轉換的結果。The data processing system further includes a convoluted inverse transforming means for inversely transforming the discrete function in a second - variable - domain back to the time domain at a second sampling frequency for converting t he input data to a set corresponding data sampled at the second sampling frequency
此資料處理系統也包含一個旋積的逆轉換裝置,用來對以第二個變數為定義領域的離散函數,逆轉換回以第二個取樣頻率為頻率及以時間為定義領域的函數,也就是將資料轉換成以第二個取樣頻率所取樣的資料。The mathematical model of each element of a stand - alone wecs including wind turbine, permanent magnet generator, rectifier, storage battery and pwm inverter is developed in the d - q rotor reference frame in chapter 3
第三章在d - q坐標軸中,建立獨立風能轉換系統中各組成部分:包括風力機、發電機、整流器、蓄電池和逆變器的數學模型。Based on the theoretical expression of the average intensity in the fourier transforming and imaging optical system with variable aperture, an algorithm is developed to change the intensity data versus the aperture radius into the bessel - fourier - transform - and - the - inversion of a function of the height - height correlation function. three samples of gaussian correlation are used for the experimental demonstration
在理論分析和實驗測量中,我們採用了變孔徑的傅立葉變換和成像系統,由所得到的像面光強的解析式,建立了將平均光強隨孔徑的數值變化關系轉化為正逆傅立葉變換對,從而恢復出表面的高度?高度相關函數。The design of excitation power source based on principle of three phase step motor and pulse width modulation ( pwm ) technology, intelligent power model ( ipm ) is used for inverter switches, the output ac pulse used as excitation signals. the speed of rotation and magnetic intensity can be changed by regulate the exciting converted frequency and magnitude of exciting current. constant current is achieved by closed loop feed back
勵磁電源結合步進電機原理與脈寬調制技術,選用智能功率模塊ipm作為逆變開關器件,輸出交流脈沖勵磁信號,以調節勵磁轉換頻率和勵磁電流大小為手段,實現對磁場旋轉頻率和磁場強度大小的有效調節,並通過閉環反饋實現閉環恆流控制。The dc / dc converter provides pulse voltage, which returns to zero periodically, for the devices in the inverter to realize zvs. but the devices still have some on - loss under two kinds of state commutation. therefore, it is better to use the devices with smaller junction capacitor
通過對逆變橋工作模式的分析,發現在兩種模式轉換的過程中功率管開通時存在一定的損耗,據此認為逆變橋功率管應採用輸出電容小的器件。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。Aggregate, pivot, unpivot, and slowly changing dimension transformations, for common data warehousing tasks
聚合、透視、逆透視和漸變維度轉換,用於常見數據倉庫任務。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。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。A novel reversible coordinate transform method, need not calculating the transform coefficient matrix, based on vector operation is proposed in this paper
摘要提出了一種基於矢量運算的新的坐標變換方法,該方法具有不需要計算轉換系數矩陣、可逆的特點。The system is composed with six sections which are entropy decoder, inverse z transform, inverse quantization, inverse discrete cosine transform ( idct ), up sampling and color space transform
Jpeg解碼演算法主要由熵解碼、逆z變換、反量化、反離散餘弦變換、內插和色度空間轉換六部分組成。The half - bridge bi - directional current mode hfl inverter can realize dc to ac conversion in only one stage. the half - bridge bi - directional current mode hfl inverter succeeds to the advantages of full - bridge hfl inverter but uses fewer power switches, which reduces the costs of switches " driver circuit
半橋雙向電流源高頻鏈逆變電路只需一級功率變換即可實現直流到交流的轉換,在繼承全橋高頻鏈逆變電路優點的同時,使用的功率管更少,功率管的減小同時降低了驅動電路的成本。分享友人