low pulse frequency 中文意思是什麼
low pulse frequency
解釋
低脈沖頻率-
This paper supplied a new way through variable frequency variable speed ( vfvs ) to change its output flow rate and adding a constant - pressure - drop valve, which could solve the defects in hydraulic pressure servo control system, such as low efficiency in control system, short life, poor ability in resisting pollution, low efficiency in driving system and flow rate, pressure pulse. and this way was proved to be effective
本論文針對傳統伺服控制系統效率不高、元件壽命短、抗污染能力差、驅動系統效率低、存在流量及壓力脈動等缺陷，利用先進的交流變頻調速技術改變液壓泵轉速的容積調速新方法，提出了在液壓系統中加一個定差減壓閥的新思路，較好地解決了液壓伺服系統存在的上述問題。 -
In the sub block circuit design, the contents that the author had introduced include : the principle of band gap voltage reference and the design technique in low power supply ; the analysis of spike pulse noise rejection, frequency divider and dead time in oscillator and control circuit ; the selection of the width and length ratio of four switches and 2x / 1x mode change point in driver and mode selection circuits
在子電路設計中，作者比較深入分析的內容有:基準電路的原理及低電源電壓下基準電路的設計;振蕩器和控制電路中尖峰脈沖噪聲抑制、兩分頻電路及死區時間設定;驅動及模式選擇電路中開關管的寬長比的選擇及模式轉換點的設計。 -
The second, at the high frequency primary coil, when switch turn on with control signal ( the spwm pulse is modulated ), in the positive or negative semi - period of low frequency modulation signal, transformer coil with same direction voltage. the magnetic flux of transformer core will increase step by step. at the end, it leads to magnetic flux saturation
二、在高頻變壓器原邊，當開關管接收控制信號脈沖列（經調制的spwm波列）導通時，在低頻調制信號的正半周或負半周內，施加在變壓器繞組上的是同一方向的電壓，變壓器磁芯中的磁通可能將級進地逐漸增加，導致磁芯飽和，造成磁偏或單向磁化，導致低頻電信號放大失真或由於很大的磁化電流而無法正常工作。 -
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。 -
In hardware, we choose anti - disturbance photoelectric isolative sensor, take rc filter to resolve high - frequency for anti - disturbance. in software, we adopt arithmetic of recursion mean value to collective signal values to resolve low - frequency ac and pinnacle pulse disturbance
在硬體方面，選用抗干擾能力強的光電隔離電量傳感器，並採取rc濾波抗干擾措施解決中高頻干擾問題；在軟體方面，對採集到的信號量採取遞推平均值演算法，解決低頻交流和尖峰脈沖干擾問題。 -
The study has completed the design of two - phase inverter and made up of the two - phase inverter - motor system for experimental use it is a variable frequency adjustable speed system with a open - loop control of rotational speed, which consists of voltage - controlled oscillator circulating assign device inverter circuit and two - phase induction motor a accurate mathematical model is set based on the whole system, and simulator program of dynamic and steady condition is established, which is used to calculate the dynamic and steady performance by kron and symmetrical coordinate converter by simulator calculation and experimental research with specific parameter of the system, a comparison is made between predicted and experimental characteristics, experimental measurements are shown to compare closely with corresponding theoretical result it is compared with some variable frequency adjus table speed system comprising inverter and single - phase induction motor from the system efficiency torque pulsation and the effect of two - phase inverter capacitance based on the conclusion, harmonic cancellation pulse width modulation control of a two - phase inverter - fed induction - motor drive system is researched, which cancelled the low harmonic and improve the system performance
通過對電機的kron變換和對稱分量變換，建立了系統較精確的數學模型，編制了系統動態及穩態運行的模擬計算程序分別計算系統的動態和穩態性能。通過對系統的具體參數進行了模擬運算和實驗研究，實驗和模擬結果進行比較，說明實驗和理論較為一致，並從系統效率、轉矩脈動及兩相逆變器電容的影響等方面與各種逆變器和單相異步電動機組成的變頻調速系統加以比較。在此基礎上，對兩相逆變器供電-異步電動機系統使用諧波抑制pwm控制進行了研究，由於減少了低次諧波，改善了系統性能。 -
Traditional laser iff has poor security because of low frequency of laser beam coded pulse. this can be greatly improved when the pulses are modulated by continuous wave laser, but the power of this laser beam output is so low that it ’ s difficult to be detected and received by laser warning subsystem
傳統的激光敵我識別器激光編碼脈沖頻率低，通信保密性差，使用連續波激光器經調制后激光編碼脈沖頻率高，保密性好，但輸出激光功率較低，難以達到激光告警分機探測接收的要求。 -
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 main circuit is consisted of 18 thyristors circuit and protection circuit. with the help of control subsystem, it can get the output of low frequency voltage ( current ) with the shape of sine wave ; the core of the control subsystem is the cpu of 87c196kc, and the synchronization circuit, the pulse - widen circuit, and the power - enlarged circuit form the accessorial subsystem of the control system. it possesses all the functions of digital triggering, digital tuning, analog / digital conversion ; the input transfer can isolate the input and output ; and the circumfluence reactor can reduce the circumfluence
主迴路採用由18個晶閘管組成的三相零式電路，並輔以晶閘管的保護電路，通過控制可以得到低頻正弦波的電壓（電流）輸出；控制迴路主要以87c196kccpu為核心，其外圍電路包括同步電路，脈沖拓寬電路，功率放大驅動電路等，完成了數字觸發、數字調節、模數轉換等功能；進線電源變壓器具有變壓和隔離作用；環流電抗器則實現了有效抑制主迴路瞬時脈動環流的功能。 -
The variable polarity power supply circuit uses two stages full - bridge inverter, the former inverter is regarded as a constant - current source with fast dynamic response, and supplys energy for the second one, and the latter one is to produce variable polarity current excellently, and low - frequency pulse current by variable polarity power supply is used to reduce input energy and control the shape of weld bead while welding. a series of high - frequency pulse current is superposed on direct - current - electrode - negative ( dcen ) current through the high - frequency pulse power supply, which is used to compress the arc and improve process of crystallization
其中變極性電源採用二次全橋逆變結構，一次逆變提供快速的響應速率並給二次逆變提供能量，二次逆變提供良好的變極性性能，使輸出能量最優化，並用其低頻電流特性減小電弧線能量，控制焊縫成形;高頻脈沖電源提供的高頻電流疊加在反極性電流dcen上，利用電流的高頻特性壓縮電弧，改善焊縫金屬結晶過程。 -
In this paper the methods of chronically implanting microelectrodes, combined electrophysiology with behavioral learning in vivo, were used to study the effects of low frequency stimulation ( lfs ) of the dorsal norepinephrine bundle ( dneb ) on the learning - dependent long - term potentiation ( ld - ltp ) at the hippocampal mossy fiber synapses onto ca3 pyramidal neurons. paired - pulse technique at the intervals of 75 - ms, 150 - ms and 300 - ms was used as the test stimulation. the results showed as follows : 1
本實驗運用慢性微電極埋植技術和電生理學結合行為學的在體研究方法，以配對脈沖檢測（間隔分別為75ms ， 150ms ， 300ms ）為檢測手段，探查了低頻（ 1hz ， 5hz ）刺激去甲腎上腺素背束（ dorsalnorepinephrinebundle ， dneb ）對大鼠苔蘚纖維- ca3 （ mf - ca3 ）突觸上習得性長時程增強（ learning - dependentlong - termpotentiation ， ld - ltp ）及動物行為習得的影響。 -
Then the pulse is modulated by pwm. after the modulated signal through a low pass filter, we can get the change of the frequency that related to the capacitor
對頻率變化的脈沖進行寬度調制，通過低通濾波就可以輸出頻率變化量，也就可以得到相應的加速度值。 -
Finally, the rules used to design the induction motor and set the inverter v / f curve are summarized to improve the stability of the system movement in the forth part of the dissertation, three measures are brought forward to eliminate the system low frequency oscillation. the first measure adopts pulse based dead time compensation to suppress the oscillation. as second measure, considering the motor and inverter as an integration, the discontinuous space vector modulated strategy named dpwm3 is proposed for the first time to suppress the oscillation
措施一是在總結常用死區補償方法的基礎上，提出脈沖為基礎的死區時間補償法（ pbdtc ）對死沈陽工業大學博士學位論文區進行補償，抑制系統的低頻振蕩;措施二是從逆變器與電機的機電一體化配合更加完善的角度，首次提出採用不連續空間矢量調制策略dpwm抑制系統的低頻振蕩;措施三是通過對系統中電機參數的調節，達到抑制系統低頻振蕩的目的;最後進行了實驗驗證。 -
The three - phase high - frequency ac pulse density modulation ( pdm ) converter, which is proposed in this paper, can efficiently synthesize low - distortion variable frequency variable amplitude low frequency voltage signals from the fixed - frequency voltage of the high frequency link
本文闡述的高頻交流脈沖密度調制（ pdm ）的控制策略能夠較容易地將高頻交流信號低失真地合成幅值和頻率變換的低頻信號。 -
Pin diode used as thermo sensor and heating component in this method, low frequency pulse power amplifier is used to substitute rf power in thermo - resistance measurement, and pulse wide compensation is used in dissipation measurement, then equipment require reduced and flexible of equipment rising
該方法以pin二極體作為感溫元件和發熱元件，採用功率脈沖源來代替射頻功率放大器對器件進行加熱進行熱阻測試，使用占空比補償法進行功耗測試，大大降低了設備要求，提高了測試設備的通用性。 -
A system for the weld power source was established with digital signal processor ( dsp ), and variable polarity power supply output, high - frequency pulse current, protection and process control were fulfilled with the software all, and modulate low frequency pulse current by means of amplitude modulation, through which it could also control the shape of weld seam like the low frequency pulse current welding
在模擬控制器基礎上引入了dsp數字控制技術，用軟體編程實現了電源的變極性輸出、高頻脈沖電流的疊加及保護和電源的時序控制，使之能夠在大尺度上調制出低頻脈沖，控制焊縫成形。 -
The main advantage of this pdm converter is that one half - cycle of the high - frequency voltage becomes the basic unit of synthesis of the low - frequency signals. the area difference under the reference signal and synthesized signal and the next pulse with the polarity will reduce thi s difference
Pdm技術的特點是將高頻交流脈沖信號的一個半周期作為合成低頻信號的基本單元，通過比較同時刻參考波形和輸出波形的面積差，使得兩個曲線包圍的面積可以基本維持平衡。
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