磁通轉變次數 的英文怎麼說
中文拼音 [cítōngzhuǎnbiàncìshǔ]
磁通轉變次數
英文
ftpi flux transitions per inch-
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 solving steps are as follows : the field is divided into three regions by the cylindrical surface of the finite - length cylinder and the location of the delta - coils. because " the surface current source is placed at the interface, the non - homogenous restricted equation on the magnetic vector potential is transformed into the homogenous helmholtz equation. by using the method of separation of variables to solve equation and according to the interface conditions and the condition at infinity to determine the unknown constants, the expressions for the magnetic vector potential of the three regions are solved out
在求解過程中,假定放置式圓柱線圈是由無窮多個對稱圓環線圈密饒而成,首先求解含有有限長磁芯的通電對稱圓環線圈的電磁場:以有限長圓柱磁芯的側面和圓環線圈所在圓柱面為分界面將場域劃分為三個小區域,由於場源放置在內邊界面上,使得關于矢量磁位的非齊次約束方程轉化成齊次亥姆霍茲方程,利用分離變量法求解,根據分界面鄭州大學碩十研究生畢業論文摘要條件以及無限遠條件確定待定常數,從而得到各場區矢量磁位的表達式。The author firstly analyzed the mathematic model of the cascaded brushless doubly - fed machine ( cbdfm ) on the dq and mt coordinate rotating at rotor speed and synchronous speed seperatly, and the equivalent circuit of steady state. the author also analyzed the stator power winding flux oriented vector control strategy of the cbdfm as vscf wind power generator and validated the validity of the model and strategy by the simulation analysis
此外,本文還首次詳盡地分析了級聯式無刷雙饋電機在轉子機械速dq坐標系、定子同步速mt坐標系下的數學模型,穩態等效電路及作變速恆頻風力發電機運行時的定子功率繞組磁鏈定向矢量控制策略,通過模擬分析驗證了模型和策略的正確性。
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