switching criterion 中文意思是什麼
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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。 -
Accordingly, a new framework, which provides a common scheme for the numerical simulation on the macroscopic behavior of ferroelectrics though multi - scale analysis on the coupled thermo - electrics - mechanical behavior of multiphase in heterogeneous material, is induced to construct the effective constitutive equation of multiphase. in chapter four, based on the law of domain nucleation and domain wall motion of 1800 domain switching, a new scheme of domain switching and numerical simulation approach is put forward on the foundation of thermodynamics. driving traction, nucleation criterion, velocity of domain wall motion, kinetic relation and rate of domain switching in a single grain are given
第四章以鐵電體1800疇變的過程中形核規律和疇界運動規律的實驗觀察結果為基礎，根據熱力學理論建立鐵電體疇變的理論框架和數值模擬方法；給出了單疇內疇變驅動力、新疇形核準則、疇界運動速度公式、疇變動力學的表達式，單晶的疇變速率公式；用細觀力學的觀點給出了對多晶鐵電體多場耦合的有效性質進行包含疇變速率影響的多尺度分析方法。 -
The twelve kinds of modes and equivalent circuits within one high frequency switching period are carefully analyses. by using the state - space averaging approach, the converter ' s averaging model is presented, the output characteristic curve and design criterion of key circuit parameters such as output voltage, filtering inductance, common conduction time, uni - polarity spwm waveform ' s duty cycle etc are given
詳細分析了這類變換器在一個高頻開關周期內的十二個工作模式及其等效電路。採用狀態空間平均法建立了變換器平均模型，獲得了輸出電壓、濾波電感電流、共同導通時間、單極性spwm波占空比等關鍵電路參數的設計準則和變換器的外特性曲線。 -
The twelve kinds of modes and equivalent circuits of this inverter with high frequency link within one high frequency switching period are carefully analyzed ; by using the state - space averaging approach, the inverter ’ s averaging model is presented, and the design criterion of key circuit parameters and the output characteristic curve are given ; the analyses of the system stabilization and the mathematic analyzes of the principle of high - frequency - link of this inverter have also be done. prototypes for 1kva 270v 10 % dc / 115v400hzac uni - polarity phase shifting controlled bi - directional voltage mode inverter with high frequency link is designed
以全橋橋式拓撲為例，論述了雙向電壓源型高頻環節逆變器單極性移相控制的原理、逆變器在一個高頻開關周期內的十二個工作模式及其等效電路;採用狀態空間平均法建立了逆變器平均模型，獲得了這類逆變器的關鍵電路參數的設計準則和外特性曲線;分析了系統穩定性，並對逆變器高頻環節原理進行了數學分析。 -
The twelve kinds of modes and equivalent circuits of voltage mode ac - ac mode ac / ac converters with high frequency link within one high frequency switching period are carefully analyses. by using the state - space averaging approach, the converter ' s averaging model is presented, and the design criterion of key circuit parameters and the output characteristic curve are given
以全橋橋式拓撲為例，論述了單極性移相控制的原理、單極性移相控制電壓源交?交型高頻環節ac ac變換器在一個高頻開關周期內的十二個工作模式及其等效電路。採用狀態空間平均法建立了變換器平均模型，獲得了關鍵電路參數的設計準則和變換器的外特性曲線。 -
Reactive power are calculated using the new algorithm. on the basis of analyzing different kinds of control strategies of var compensation, the paper applies the criterion of voltage and var to control switching and illustrates a improved mode of switching capacitor which can prevent the switched - capacitor from the impacting of instantaneous rush currents by means of zero - crossing triggering of scr components, and can realize auto - tracking var and auto - switching shunt capacitor bank. initial operating parameters are stored in information flash memory of the mcu using flash self - programming technique in order to decrease complexity of the circuit and improve stability
高壓智能無功補償控制器以flash型16位單片機msp430f149為控制核心，採用了一種相角實時測量的新演算法，並在此基礎上計算出了功率因數、有功和無功，減少了運算量提高了精度；在分析了各種無功補償控制策略的基礎上，以母線電壓和無功功率復合判據控制投切，並提出一種改進的電容器投切方式? ?暫態投切控制晶閘管過零觸發，避免了電容器投切時的電流沖擊；穩態運行時接觸器替代晶閘管，實現無功補償的自動跟蹤和電容器的自動投切，解決了投切時的暫態電流沖擊和穩態時可靠運行的難題；控制器的原始運行參數採用flash自編程技術，將其保存在msp430f149片內的信息flash中，簡化了硬體電路，大大提高了系統的可靠性。 -
In particular, a switching criterion is developed, with which the hybrid scheme can switch from css to dcss automatically at the time when noise is suppressed
特別地，通過一個能夠衡量圖象噪音強度的指標函數，混合演算法能夠在噪音被消除后自動由css演化轉換為dcss演化。
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