查询词典 instantaneous voltage

By using this method, the angular frequency, amplitude, initial phase angle, decay constant of each component in transient voltage and/or current waveforms can be precisely extracted. Also, all other kinds of transient procedure can be analyzed by this method. Thirdly, a new definition of generalized instantaneous reactive power and generalized instantaneous reactive current in dq0 coordinates under any nonsinusoidal and unbalanced three-phase circuit is proposed for the first time. The detection and compensation method for different instantaneous reactive currents are also concerned.

本文首先提出了用于快速高精度频谱分析的一种改进快速傅立叶变换方法，该法具有速度快、精度高、抗混迭、不受采样定理约束、可以分析出谐次大于N／2的频谱系数等特点，可方便地应用于电力系统谐波分析及其它各类频谱分析；然后提出了基于非线性最小二乘优化法的电力系统暂态波形分析方法，可准确求出电力系统暂态电压、电流波形中各个分量的角频率、幅值、初相角及衰减常数，并可广泛应用于各类暂态过程波形分析。

According to the instantaneous value of transmission line voltage, the current instantaneous values of shunt reactors and 17 equivalent circuit capacitance can be calculated.

由线路电压瞬时值分别实时计算出流入并联电抗器和流入线路Ⅱ型等值电路两侧电容的电流瞬时值，再从线路每侧电流除去这两部分电流，用得到的新电流瞬时值作常规采样值差动和故障分量采样值差动保护计算。

Simulation and experimental results indicate that for the SPWM inverter based on instantaneous output voltage feedback control,the fundamental open circuit output voltage incr...

仿真和实验结果表明，对于采用瞬时输出电压反馈控制技术的SPWM逆变器，其输出电压在空载时随着死区时间的增加而增加，负载电流超过临界电流后其输出电压随死区时间增加而下降；其阻性负载时的外特性曲线是一条先下降后上升的曲线。

Based on the instantaneous output voltage and filter inductor current double closed loop feedback control and through sharing the same voltage regulator, the current sharing is achieved.

基于主从控制的逆变器并联系统由3个采用输出电压瞬时值和滤波电感电流瞬时值双闭环反馈控制的逆变器模块构成，通过共用电压调节器实现负载均分。

The instantaneous power theory was employed to analyze the instantaneous power of the control winding and the control scheme for the DWIG system with diode bridge load was obtained. The component of the currents on the control-winding flux determines the instantaneous reactive power, and the component on the perpendicular direction of the flux decides the reactive power. The former one influences the DC voltage of the diode bridge on power winding and the latter one influences the DC voltage of the static excitation controller of control windings.

基于瞬时功率理论，推导出按控制绕组磁场定向时控制绕组的瞬时功率，在此基础上分析了带整流桥负载的定子双绕组感应电机发电系统在宽转速运行时的电压调节机理，即：控制绕组电流在控制绕组磁场及其法线上的分量，分别决定着发电系统功率绕组整流桥直流侧电压和控制绕组静止励磁控制器(static excitation controller，SEC)直流侧电压，据此提出宽转速运行时DWIG发电系统电压控制策略。

It is introduced that harmonic current in the electric network and harmonic current detecting method based on instantaneous reactive power theory in the paper,and then it presents the current detecting method in the anisomerous mains voltage,aberrance circuit based on instantaneous reactive power theory .

通过对电网谐波和瞬时无功功率理论在谐波检测中应用的分析研究，作者给出了基于瞬时无功功率理论的检测方法在电网电压不对称、存在畸变时的电流检测方法。

Through theoretic reckoning and simulating analyzing, several control strategies for shunt APF were compared and chose ip-iq arithmetic ofthe instantaneous reactive power theory control strategy as the right scheme to produce the instructing current. Based on it, some new control arithmetic was subjoined to suppress the resonance in system and balance the dc side capacitor voltage. Two topologies of main circuit were compared and chose the three-phase voltage-source converter with a split-capacitor as its main circuit structure. The numerical scales of the dc side capacitor and inductance of reactors were calculated. The high-pass filters were designed to eliminate effectively the highfrequency harmonics produced by APF.

通过理论计算和仿真分析，比较了并联型APF的几种控制策略的优点和缺点，从中选择瞬时无功理论控制策略i_p-i_q计算方式为指令电流产生的算法，并在此基础上增加了抑制系统谐振和平衡直流侧电容电压的控制；比较了并联型APF主电路的两种常见形式，从中选择了三相电压型变流器的主电路形式；算出适合该APF的直流侧电容和出线电感的参数；设计出能有效消除APF产生的高次谐波的高通滤波器。

On the basis of instantaneous forced analysis to short circuit of power transformer and numerical value calculation using low voltage impulse analysis, the paper presents the essentiality of winding distortion after short circuit of power transformer. By contrasting the three main ways of the world such as low-voltage impulse、 short circuit impedance analysis and frequency response analysis , FRA is adopted for distortion testing. Then we design a new testing instrument of transformer winding distortion—testing system of transformer winding distortion.

本文首先在对电力变压器短路时的瞬时受力分析及所受电磁力的有限元法的数值计算的基础上，论证了电力变压器短路以后进行绕组变形测试的必要性；然后通过比较的方法对目前国内外主要使用的三种方法：低压脉冲法、短路阻抗法和频率响应法，进行了一一对比，并根据对比结果，确定在本课题中使用频响法；最后在理论研究的基础上，设计出了一种新型的变压器绕组变形测试仪——电力变压器绕组变形测试系统。

In order to solve this problem, a control strategy is developed. A control algorithm to suppress negative sequence current through ASVG caused by slight asymmetry of system is also developed based on the modeling method in function of switchings and the definition of instantaneous negative sequence voltage. The ASVG can generate a negative sequence voltage component against that in the system while it generating positive sequence voltage with this algorithm.

在系统轻度不对称时，本文提出了通过控制ASVG触发脉冲使其产生与系统电压负序分量大小和相角完全相同的负序电压以抵消系统电压负序分量，从而抑制ASVG负序电流的方法，并用&开关函数&建模法给出了具体的控制算法。

At first the current sampling values pass through virtual digital CVTs. And then the voltage and current sampling values are processed by a low pass filter. According to the instantaneous value of transmission line voltage, the current instantaneous values of shunt reactors and P equivalent circuit capacitance can be calculated. After removing these two kinds of current, sampling value differential protection based on all components and fault component can be applied.

由线路电压瞬时值分别实时计算出流入并联电抗器和流入线路Π型等值电路两侧电容的电流瞬时值，再从线路每侧电流除去这两部分电流，用得到的新电流瞬时值作常规采样值差动和故障分量采样值差动保护计算。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。