頻率變換調制 的英文怎麼說

中文拼音 [bīnlǜbiànhuàndiàozhì]
頻率變換調制 英文
frequency shift keying （fsk）
  • 頻 : Ⅰ形容詞（次數多） frequent Ⅱ副詞（屢次） frequently; repeatedly Ⅲ名詞1 [物理學] （物體每秒鐘振動...
  • 率 : 率名詞（比值） rate; ratio; proportion
  • 換 : 動詞1. （給人東西同時從他那裡取得別的東西） exchange; barter; trade 2. （變換; 更換） change 3. （兌換） exchange; cash
  • 調 : Ⅰ動詞1 （配合得均勻合適） harmonize; suit well; fit in perfectly 2 （使配合得均勻合適） mix; adju...
  • 制 : Ⅰ動詞1 （製造） make; manufacture 2 （擬訂; 規定） draw up; establish 3 （用強力約束; 限定; 管束...
  • 頻率 : frequency; rate
  1. And the most advantage of ofdm is that it can convert high - rate data stream into the low - rate and reduce data bandwidth so that multi - path - fading can be transformed into flat fading in wireless circumstance

    這種調制技術的最大的好處就是將高速的數據流，變換成并行的低速數據流，減小了數據帶寬，從而可將無線環境中的多徑衰落（頻率選擇性率落）轉換成平坦衰落。
  2. The temperature range is - 30 ~ 80. the topology of the step - up dc / dc converters and its basic principle is first analyzed in this thesis. then based on the conventional pfm control scheme, a discrete pulse frequency modulation is presented and the state space average model related to the ccm ( continue current mode ) and dcm is established

    然後在傳統的脈沖頻率調制方式的基礎上，分析了一種離散脈沖頻率調制方式，並建立了這種調制方式下升壓型dc / dc變換器在電流連續（ ccm ）工作模式和電流斷續（ dcm ）工作模式的狀態空間平均模型。
  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. At present, people usually use birefrigence and quasi - phase - matching methods to achieve higher effiency in the process of conversion. a significant advantage of quasi - phase - matching method is that the interaction is occurred through the largest element of the x ( 2 ) tensor ; the period of optical superlattice can be designed randomly, and any interaction can be matched without walk - off angle ; they are fitted to be used in frequency conversion of lower power especially. the quasi - phase - matching method has some advantages over birefrigence method, improving the efficiency of frequency conversion ; the range of frequency conversion covers its whole transperant wavelength

    由於準相位匹配技術有其獨特的優勢，可以利用非線性光學晶體的最大二階極化張量，如ppln 、 pplt 、 ppktp用的非線性極化張量都是d _ （ 33 ） ，其有效非線性系數高出普通非線性光學介質（如bbo 、 lbo 、 ktp ）一個數量級，而且可以人為靈活設計調制周期，通過周期設計其頻率變換范圍可以覆蓋準相位匹配介質的整個透明波段，選擇無走離效應，解決了常規pm難以解決的問題，拓寬了非線性晶體的應用范圍，極大地提高了頻率轉換效率，已成為非線性光學材料和固體激光器的研究熱點之一。
  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. Direct modulator converts baseband signal to rf signal without upconvertion. the system design is relatively simple compared to upconversion. so direct modulator provides adventages of compact size, low cost and low spurious response

    直接調制將基帶信號直接轉換為射頻信號，不需要二次頻率變換，與上變頻方式相比系統結構簡單，降低了對濾波器的要求，具有體積小，重量輕，成本低等明顯的優點。
  7. The theory basis for medium frequency receive includes sample theory, the signal ' s orthodoxy transform theory, multi - rate digital signal processing theory and signal ' s modulation and demodulation theory

    中頻數字接收的理論基礎是信號的奈奎斯特采樣定理或帶通采樣定理，信號的正交變換原理，多采樣率數字信號處理原理以及信號的調制解調理論。
  8. The steady frequency three - phase ac can be changed into the ac which frequency is continuously adjusted in the experiment unit composed of rectifier, inverter, control circuit, and relay safeguard circuit

    Spwm三相變頻實驗單元能夠把頻率固定的三相交流電變換成頻率連續可調的三相交流電，它主要包括交直變換、逆變、控制和繼電保護電路。
  9. The system is based on chopper constant current drive technique, according to the top level design idea, adopting advanced specical subdivision control integrate circuit and powerful function 80c196kc to organize the system frame, desiging the minimum system of single - chip microcomputer, multifunction i / o interface circuit, relay switch circuit, keyboard and display circuit, multifunction digital setting interface circuit and so on, utilizing the hso and hsi interface circuit which are owned by this single - chip microcomputer exclusively and its powerful command system to realize dual - degree switch control, automation orientation, automatically searching zero position, locking machine when stopping, frequency to set digitally, automatically adjusting speed through changing frequency, swithing subdivision or squarewave control, on the basis of above, the system also have the function of running according to the setting steps and the frequency, voltage and current to display through the led, etc

    系統基於斬波恆流驅動技術，按照頂層設計思想，採用先進的專用細分控制電路和功能強大的80c196kc單片機來組建系統構架，設計了單片機最小系統、多功能i o介面電路、繼電器切換電路、鍵盤顯示電路和多功能數字設定介面電路等，利用該單片機獨有的hso和hsi介面及其強大的指令系統，實現了雙余度混合式步進電動機的余度切換控制、自動定位、零位自動搜索、停機鎖定、數字化頻率設定、自動調頻變速控制、細分方波切換控制，在此基礎上，該系統還設有按預置步運行、 led頻率電壓相電流顯示等功能。
  10. The simulation results prove that the pdm control theory can be fit for the high frequency ac link power conversion distribution system, especially be suitable for the electric driver system of the electric vehicle in the future

    模擬結果表明，本文提出的這種高頻交流脈沖密度調制技術適用於高頻交流環節功率變換分佈系統，特別適合於作未來電動汽車的高頻交流驅動系統。
  11. The three - phase high - frequency ac pulse density modulation ( pdm ) converter, which is proposed in this paper, can efficiently synthesize low - distortion variable frequency variable amplitude low frequency voltage signals from the fixed - frequency voltage of the high frequency link

    本文闡述的高頻交流脈沖密度調制（ pdm ）的控制策略能夠較容易地將高頻交流信號低失真地合成幅值和頻率變換的低頻信號。
  12. At present, there are three kinds of modes of modulation including pulse width modulation ( pwm ), pulse frequency modulation ( pfm ) and the modulation of combination of pwm and pfm. lots of products using above modulations are designed in many famous companies

    目前，在功率變換系統中常見的有三種調制模式:脈寬調制模式（ pwm ， pulsewidthmodulation ） 、脈頻調制模式（ pfm ， pulsefrequencymodulation ）和二者可以相切換的pwm / pfm模式。
  13. 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。
  14. However, it is difficult to make the product available because most of the academic institution focused on certain aspect only. the experts indicate that the ic designers should know more about the system though they don ’ t design the system directly. it points out a way for us ic designers when we are engaged in the research work

    本文提出的開關變換器，利用反饋原理將輸出電壓穩定在某一需要的值，根據負載的不同而採取兩種控制模式，即脈沖寬度調制（ pwm - pulsewidthmodulation ）模式和脈沖頻率調制（ pfm - pulsefrequencymodulation ）模式。
  15. The transform uses the scale of the signal to decompose and make self - adapting frequency band partition of the input signals. therefore the amplitude value and the modulating frequency of the flickering signal can be obtained. with the instantaneous frequency in this method, the present study also analyzes the signal in terms of both time and frequency, and thus gets the time at which the flickering signal occurs and terminates

    運用該變換從信號本身的尺度特徵出發對信號進行分解的特點，對輸入信號進行自適應的頻帶劃分，從而求出了閃變的調制信號幅值和調制頻率;利用該方法中的瞬時頻率概念，從時頻兩方面同時對信號進行分析，從而獲得了閃變信號的發生時刻和終止時刻，得到了較好的檢測效果。
  16. Comparison research verifies its effectiveness on reducing the de - link losses and improving the output performance. the three topologies mentioned above are all presented with detailed theoretical analysis, parameters design, simulation and experimental verifications. a 6kw three - phase inverter system is accomplished in order to verify that the two - amplitude control technique is fit for high power application

    第五章研究三相逆變系統的雙幅諧振直流環節技術，完成了6kw實驗系統，提出了滯環電流控制與空間矢量調制相結合的方案（ hcc - svm ）並首次採用cpld實現邏輯控制，大大降低了逆變器換流頻率，縮短了控制延時，實現了逆變器的高效變換和低輸出失真。
  17. Further, the characteristics such as the response speed, the efficiency and the relationship between load and the modulation factor are counted and analyzed. during the stage of circuit design, the whole chip and the sub - block circuits are well - designed, respectively

    基於此模型，計算並分析了離散脈沖頻率調制下升壓型dc / dc變換器的響應速度、效率和負載與調制度的關系等特性。
  18. The author pays more attention to the analysis and design on the following sub - circuits : oscillator, comparator, hysteresis comparator, chip enable, etc. on completing the principle analysis and circuit design, the sub - circuits and whole chip circuit are verified with the eda tools hspice

    其次在電路設計中，作者基於升壓型dc / dc變換器和離散脈沖頻率調制方式的基本原理並根據電路功能的需要，進行了控制電路的總體結構設計和子電路模塊設計。
  19. First, variable speed constant frequency wind energy convertion theory is described in this paper, then presents a review on the development of wind turbines control and the main types of generator and static converters used to interface variable speed wind turbines to the electric grid. then discuss main circuit constructure and advantage of direct drive wind energy conversion system and introduce pitch - control method for wind power traction and electric power stability. simply aerodynamic characteristic of the turbine is analysised and permanent magnet synchnonous generator math model is established. to convert the variable frequency electricity into utility grid, back to back four - quadrant pwm - vsi is used and three typies of control strategy is presented to capture the maximum wind energy and transmit energy. then simulation is implemented to test the control strategy. in the following chapter a simple ac - dc - ac converter with a dc - dc boosting chopper is proposed to transmit the wind energy into electricity energy and two control strategy is presented

    建立了永磁電機和變流器的數學模型，針對雙pwm變頻器的特點提出了三種控制策略對變流器進行控制，通過變流器交-直-交的變換，將發電機發出的變頻變幅值交流電轉化為可用的恆定頻率的交流電，通過pwm調治能使其輸出功率因數為一，並且該控制系統功率因數為可調，能在特殊情況下同電網交換一定的無功功率，並通過對變流器的控制實現了最大風能俘獲的功能。最後採用matlab / simulink進行了模擬，取得了良好的模擬效果。在風力發電系統中，採用先進的最大功率俘獲演算法，能有效的從風中獲得最大的能量。
  20. It makes the analysis of signal twitter and modulation very easy and the measurement of frequency drift and converting very simple

    它使信號的抖動分析、調制分析非常直觀，使頻率漂移測量、頻率轉換特性測量變得十分簡單。
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