正弦波轉換 的英文怎麼說
中文拼音 [zhēngxiánbōzhuǎnhuàn]
正弦波轉換
英文
sine wave switching-
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。The main circuit is consisted of 18 thyristors circuit and protection circuit. with the help of control subsystem, it can get the output of low frequency voltage ( current ) with the shape of sine wave ; the core of the control subsystem is the cpu of 87c196kc, and the synchronization circuit, the pulse - widen circuit, and the power - enlarged circuit form the accessorial subsystem of the control system. it possesses all the functions of digital triggering, digital tuning, analog / digital conversion ; the input transfer can isolate the input and output ; and the circumfluence reactor can reduce the circumfluence
主迴路採用由18個晶閘管組成的三相零式電路,並輔以晶閘管的保護電路,通過控制可以得到低頻正弦波的電壓(電流)輸出;控制迴路主要以87c196kccpu為核心,其外圍電路包括同步電路,脈沖拓寬電路,功率放大驅動電路等,完成了數字觸發、數字調節、模數轉換等功能;進線電源變壓器具有變壓和隔離作用;環流電抗器則實現了有效抑制主迴路瞬時脈動環流的功能。This paper include the following parts. firstly the sine exciting - voltage is guaranteed by direct digital synthesize technology ; secondly the digital output of cos ( 9 ) and sin ( 9 ) are generated by microcontroller ; thirdly the two voltage signals which are the product of the two former signals gained by the multiplying d / a converter, being filtered and amplified, have constant frequency, and one amplitude has sine function relationship of with the input angle, and the other amplitude has cosine function relationship of with the input angle ; finally the two signals are acquired and analyzed by relative instrument and software
主要由以下幾部分組成:用數字頻率合成技術( dds )產生正弦激勵電壓信號u _ msin ( t ) ;用單片機產生幅度的數字量輸出sin ( )和cos ( ) ;用乘法型d a轉換器實現激勵電壓和幅度的乘積,並通過濾波器和功放后即得到頻率固定,幅值隨輸入角成正餘弦變化的電壓信號;最後用數據採集卡採集輸出信號,顯示波形並進行頻譜分析。The signal testing unit examines directly the production parameter - the belt " s velocity and sends out electrical signal similar to sine wave. the signal handling and analyzing unit disposes of the sensor " s output signal by amplifying, plasticisering a / d transforming and measuring and displays it digitally. after the alarming and controlling unit compares the testing signal with the standard one and analyses, it will show the normal production situation or alarm at the abnormal state and control the related equipments if it is necessary
信號檢測單元直接檢測皮帶速度,並輸出近似正弦波的電信號:信號處理與分析單元對傳感器輸出信號進行放大、整形、 a d轉換和計算等處理,並進行數字顯示;預警、報警、控制單元將信號與標準信號進行比較,經分析后顯示正常狀態或對異常狀態進行聲、光預警、報警。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。The second part is a detector which is used to detect the distribution of voltage on the patient ' s brain surface from all different directions. the third is a mixed signal processor ( c8051f020 ) which is used to control the other parts of the system and display some necessary information and convert the voltage signals into digital signals, as well as transmit the acquired data to the computer. the fourth is computer with eit software which is used to analyze and process the received data and construct a picture for the brain edema and haematoma on screen
32通道電阻抗斷層成像系統由4個部分組成:第一部分是正弦波恆流源,用來產生注入大腦的激勵電流;第二部分是電位信號的提取與轉換,用來提取當激勵電流注入時,在大腦表面形成的電位分佈信號;第三部分是數據採集與控制系統,用來控制激勵電流的頻率,注入方向,注入強度,控制採集大腦表面的電位分佈信號,並且將這些採集的電位分佈數據傳到pc機;第四部分是計算機eit成像軟體,用來接收下位機的電位分佈數據,並且對這些數據進行分析計算,重建電阻抗圖像。This dissertation presents several novel control techniques for the torque ripple minimization of pm bldcm. according to the different back - emf waveforms of bldcm, this dissertation gives a detailed analysis to the torque ripple due to trapezoidal emf, pseudo - sinusoidal emf, and general shape emf respectively, and from each one proposes a kind of control technique for torque ripple minimization
根據永磁無刷直流電動機反電勢波形的不同,對方波型無刷直流電動機的換相轉矩脈動,準正弦波( pseudo - sinusoidalemf )反電動勢無刷直流電動機以及任意波形反電動勢無刷直流電動機的電磁轉矩脈動,進行了詳細的分析,分別提出三種不同的控制策略,進行轉矩脈動抑制控制。This text described to use an memorizer with some additional and necessary of controlling by the conversion electric circuit according to the dds principle in order to produce the principle of sine wave and carry out a method
摘要敘述了基於dds原理,用存儲器附加必要的控制和轉換電路可產生正弦波的原理和實現方法。Firstly, according to the characteristic that the doppler frequency shift signal can be approximated as a single sinusoid signal, the extended sinusoid signal retrieval ( pisarenko and esprit ) methods are presented and signal state and measurement formulations are developed, so the kalman filter recursive method is got. the brief introduction of low velocity moving target doppler frequency shift signal wigner - ville transformation and wavelet transformation expression are presented in this paper. secondly, because the clutter is gaussian distribution, cumement and high - order spectrum based methods are presented and the simulation results prove their good performance to suppress gaussian clutter in low velocity moving target doppler frequency shift signal processing
一個方面是根據低速目標的多普勒信號可簡化為單一正弦波形式這一特點,得到了擴展的高斯色噪聲背景下的諧波恢復演算法,即高斯色噪聲中的pisarenko諧波恢復法和旋轉因子不變法( esprit ) ;並推導了信號的狀態方程和觀測方程,進而得到基於卡爾曼濾波的遞推演算法對信號進行提取;本文還簡單的介紹了低速運動目標的多普勒頻移信號的wigner - ville變換與小波變換;另一個方面是針對雜波服從高斯分佈這一特點,提出了對接收信號求累積量和高階譜來對高斯雜波進行抑制。In the course of exploiting the system hardware, we adopt the low frequency sine wave excitation technology whose frequency is alterable, and scheme out the new signal conversion & amplifying circuit, the new lcd circuit and the new system anti - interference circuit
在系統硬體電路的開發中,我們採用了頻率可調的低頻正弦波勵磁技術,並設計出新穎的信號轉換放大電路、液晶顯示電路和系統抗干擾電路。Chapter three : introduces the design of the electromagnetic flowmeter hardware system, lays stress on analyzing the conversion & amplifying circuit, the excitation sine wave occurring circuit, the analog - digital conversion circuit, the keyboard display interface circuit, the communicating interface circuit and the anti - interference circuit
第三章重點對電磁流量計硬體系統的轉換放大電路、勵磁正弦波發生電路、模數轉換電路、鍵盤顯示介面電路、通信介面電路,系統抗干擾電路等進行設計和分析。分享友人