正弦量角器 的英文怎麼說
中文拼音 [zhēngxiánliángjiǎoqì]
正弦量角器
英文
sine protractor-
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。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 performance of the electric vehicle is improved greatly in which the harmonic wave of output voltage, power loss and torque pulsation of the system are decreased by controlling the switch angles
它運用規則采樣法產生正弦脈寬調制波,通過開關角的控制抑制逆變器輸出電壓中的諧波分量,降低了電動機的損耗和轉矩脈動,使電動車的運行性能得到了較大改善。
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