point of zero voltage 中文意思是什麼
point of zero voltage
解釋
電壓零點-
High - frequency link power converters are receiving increasing attention. when the input frequency of ac - ac converter is quite high, such as 20khz or above, in order to make sure the converter switching action is restricted to the zero crossing point of the link voltage, the switching cycle becomes discrete pulse spectrums, however, the conventional pwm converters are ruled out because they would fail either to the efficiency or the low - distortion criteria
當交-交變頻器的輸入頻率非常高，通常為20khz時，為了在零電壓條件下實現逆變器開關管的通斷，變換器的開關時刻必須選擇在高頻交流電壓脈沖為零時，這意味著變換器開關時刻在時間軸上成為不連續的點，而常規的硬開關pwm變換器是將開關時刻選擇在任意時刻。 -
Then one of the methods of rotor position detection - bemf zero crossing point detection is explained in detail. in succession, the chapter dissertates the method of measuring phase voltage and supply voltage, and analyses the error of rotor position using this method
對轉子位置檢測方法中的反電勢過零點法作了比較詳細的介紹，討論了反電勢法中相電壓和端電壓的檢測方法，並分析了利用該方法時而產生的轉子位置檢測誤差。 -
The program is written by assemble language to control the movement of the vacuum circuit breaker with pma. the program also can monitor the environmental temperature, control voltage, closing displacement, zero point of contactor voltage
用匯編語言編製程序對配永磁機構的真空斷路器的分、合閘進行控制，同時對其運行的環境溫度、控制電壓、合閘位移和觸頭間隙電壓過零點等狀態進行實時監測。 -
The chip jk3ce that is one of micro - controllers in motorola 68hc08 family is used as control unit in this system. the zero crossing point of the back emf can be obtained by comparing the terminal voltage with the virtual neutral point, then using the software of the system can figure out the commutation period. the electronic commutation replaces the mechanical commutation in this way
本系統採用的控制晶元為motorola系列單片機中的jk3ce ，反電勢過零點可以通過比較電機端電壓和虛擬中點電壓來得到，將過零點信號送往單片機捕捉埠後由系統軟體來確定換相時刻，這樣就可以由電子換向裝置替代機械換相裝置，有利於提高系統運行的可靠性，並降低了系統維護的費用。 -
According to the characteristic of subway power alternating current transmission line, a new synchronous method based on reference zero point of the wave shape of voltage was proposed. the method is suitable to short distance line such as the subway power alternating current transmission line
根據地鐵電力交流聯絡線的特點，作者提出了一種適合於短距離線路保護的參考電壓零點的同步演算法，並對該演算法的優缺點進行了詳細的分析與模擬。 -
According to the present actual underground power system which neutral point is grounded through arc suppression coil in many supper big shaft, the development history and present situation of synthetic protection system used in hv flameproof switchgear are reviewed, and on the basis of analyzing the problems existed in high voltage flameproof switchgear, the selective leakage protective method based on the detecting harmonic direction of zero sequence current as well as the value of zero sequence voltage is proposed in this paper, and at the same time, harmonics extracting schematic and transforming circuit are also designed
本文深入系統地研究了基於intel80c196kb單片機控制的6kv防爆開關綜合保護系統，主要內容如下：針對大型及特大型礦井供電系統中性點普遍採用消弧線圈接地方式的現狀，回顧了國內外礦用高壓防爆開關保護系統的發展歷史，分析了目前國內高壓饋電開關保護系統所存在的問題，提出了「基於零序電壓基波啟動，五次諧波功率方向比較」的選擇性漏電保護原理，設計了相應的五次諧波提取電路和功率方向鑒別電路。
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