negative induction 中文意思是什麼
negative induction
解釋
負誘導-
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 present paper covers the study on textured exchange of nematic - chocesteric liquid crystals with negative decectric anisotropy under electric field induction
摘要對負性向列-膽甾相液晶在電場作用下的織構改變做理論分析。 -
To reduce the high starting current as asynchronous motors start up directly and eliminate the negative influence that brought about by switching of contact when it starts up with reduced - voltage means, two new methods based on power electronics technology for improving the starting characteristics of three - phase induction motor are presented. one is alternative voltage regulator, the other is alternative voltage chopper. the three - phase regulating circuit - asynchronous motors system and the three phase chopper circuit - asynchronous motors system are analyzed and simulated with matlab
為解決上述問題，本文提出一種基於斬波方式的三相交流異步電動機的軟起動新方法，論文對電路的起動特性、功率因數、諧波以及控制策略進行了研究，模擬結果表明這種基於斬波方式的三相交流異步電動機的軟起動方法比基於三相交流調壓的三相交流異步電動機的軟起動方法具優越性。
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