In the sinusoidal alternating circuit that only contains an inductor, the voltage across the inductor leads the current through it by 90 °, and they have the same frequency. 在只含有电感的正弦交流电路中,电压超前电流90°,且它们具有相同的频率。
As high frequent pulse wave and voltage peaks when switching IGBT tubes are added to voltage and current waveforms, it leads to disadvantageous effects on welding power and welding processing control. 推挽正激变换器是低压大电流输入场合的理想拓扑之一,但其输出整流二极管上由于反向恢复产生很高的电压尖峰。
Research of voltage reflection of PWM Inverter-Fed Induction Motor with long motor leads PWM逆变器驱动异步电动机采用长线电缆时电压反射现象的研究
The voltage and flux errors at the sampling instant can then be compensated for in the next control period, so the errors are always kept small, which leads to small fluxes and torque ripple. 由于采样时刻的电压和磁链误差,可在下一个控制周期内得到补偿,因此转矩和磁链的误差始终很小,二者的脉动很小。
The reason of the capability of heterojunction device can be operated at reverse bias voltage is that enough high electric field leads to the tilt of energy band, then the tilt of energy band makes the injection barrier thin enough to be injected by carriers through tunnel. 反向偏压下器件获得发光的原因是高场强使得能带高度倾斜,高度倾斜的结果使得载流子的注入势垒变得足够薄从而被载流子隧穿,从而导致载流子的注入和复合。
Results Twenty-one cases were abnormal after chemotherapy, the abnormal rate was 31% ( 21/ 68), and the abnormal changes were T wave, sinus tachycardia, low voltage of limb leads, ventricular extrasystole and so on. 结果化疗后出现T波改变、窦性心动过速、肢导低电压、室性心动过速、室性早搏、左前分支阻滞等心电图改变21例,异常率为31%。
Methods The voltage of QRS wave were measured with 12 leads electrocardiogram by electrocardiograph. 方法应用心电图机描记常规12导联心电图,按心电图测量标准测量QRS波群电压。
The partial discharge can be generated continuously in the short oil capacitor under lower voltage, which finally leads to the damage of capacitor. 电力电容器缺油会在较低电压下产生持续局部放电,最终破坏电容器。
Because of its unbalanced direct current resistance, the four-helical structure of low voltage leads used by traditional power transformers resulted in circumfluence inside the transformer, which increased loss and reduced efficiency. 电力变压器传统的低压引线四螺旋结构由于直流电阻不平衡的原因,导致变压器内部产生环流从而增加了变压器损耗,降低了效率。
The study on various wave voltage amplitude values of ECG limb leads of medical students 医学生心电图肢体导联各波电压幅值的研究
All indicate that the higher RF power gives rise to a higher RF negative self-bias voltage and therefore a higher ion energy, which enhances the effect of ion bombardment and leads to a graphitization of a-C: H films and a reduction of the hydrogen content. 两者表明射频功率越高,射频自负偏压越高,离子能量越高,离子对膜的轰击作用增强,导致了薄膜石墨化和膜中H成分的减少。
This paper reports that the Studying of the change range of the voltage amplitude values of P, R, Sand T waves of ECG limb leads of the medical students. 本文对医学生心电图肢体导联中P、R、S、T波的幅值变化范围进行了研究。
The initial rotor position is estimated by a suitable sequence of voltage pulses intermittently applied to the stator windings at standstill and the measurement of the peak current values of the current leads to the rotor position. 转子初始位置估计是在电机静止时,在瞬间对定子绕组施加合适的电压脉冲序列,通过测量峰值电流获得转子位置信息。
The un modulated uni voltage reflector was used inside the flat cathode ray tube to realize the technical advantages, including fewer electrical leads, simple structure, and convenience for raster correction, in the design of the horizontal linear deflection. 提出了在扁平显像管内用非调制单电压反射极来实现水平线性偏转的设计,它具有引出线少、结构简单、易于光栅校正等优点;
To reduce the switching losses of IGBTs in PWM rectifier, a third order square wave is added to the phase voltage control signal on the basis of the Improved Period Average Model. This new control algorithm leads to no switching in about 1/ 3 cycle. 为降低PWM整流器的开关频率,本文在整流器的改进周期平均模型基础上,在相电压控制信号中叠加三次方波信号,使得整流器中的开关管有1/3时间不动作。
In the diode single-phase half-wave rectification capacitor filter circuit, the output voltage on the load resistance leads to errors in the measurement. 二极管单相半波整流电容滤波电路中,由于负载电阻上有脉动的输出电压,所以给负载电阻的测量带来很大的误差。
However, Applying a voltage step to a ceramic capacitor causes a large current surge that stores energy, in the inductances of the power leads. 然而,实际应用中的电压阶跃在陶瓷电容上可能产生较大的浪涌电流,并在电源电感中贮藏能量。
Therefore, the connection of several lower-level inverter elements may significantly improve the voltage-resistant level of the equipments. At that time, there will be the phenomena of uneven distribution of the voltage of each inverter, which leads to the damage to the device. 因此,将几个耐压等级较低的逆变器元件串联使用可以显著提高设备的耐压等级,但同时会出现各个逆变器上的电压分配不均的问题,从而导致器件的损毁。
Further increasing the applied voltage, the bifurcation of the square superlattice pattern to a hexagonal pattern makes the enhancement of the spatial symmetry of the system, while leads to the reduction of the temporal symmetry of the filaments. 进一步升高外加电压,超四边形斑图分岔为六边形斑图,此时斑图的空间对称性又有所提高,同时放电丝放电的时间对称性也大大的降低。
The effect of the gate voltage on boron doped ( 6, 0) is weakened when the bias is added on the both leads. 在两端加上偏压时,门电压对硼掺杂(6,0)管的影响有所削弱。
China will construct large interconnection power grid fundamentally based on the Ultra High Voltage ( UHV) power transmission lines. The complexity of power grid is being increasingly expanded, which leads to more complication of power flow control. 未来我国将建成以特高压网架为骨干的大型互联电网,交流电网的复杂程度不断增加,潮流控制问题变得更加复杂。
In order to facilitate analysis of the problems related to physical quantities of the induction motor phase voltage, it leads into such as the necessary coordinate transformation. 为了便于问题的分析,对感应电机的相关物理量诸如三相电压进行了必要的坐标变换。
The inverter generates high frequency common-model voltage, which leads to shaft voltage and bearing current and induces bearing failure. It affects the safety and reliability of the electrical drive system seriously. 尤其在应用PWM变频器后,由于逆变器在电机定子绕组中产生高频的共模电压,使电机系统产生轴电压、轴电流,导致轴承被损坏,严重影响了电气拖动系统的安全性和可靠性。