查询词典 instantaneous power

Power system ; Three-phase circuit ; Nonsi-nusoidal circuit ; Unbalanced circuit ; Instantaneous reactive power

电力系统；三相电路；非正弦电路；不平衡电路；瞬时无功功率

The result indicates that the harmonic detection means based on instantaneous reactive power theory can detect harmonic and reactive component in three-phase current precisely and real-time, to supply reliable harmonic and reactive current for harmonic restraint and reactive power compensation.

仿真结果表明：基于瞬时无功功率理论谐波检测方法可以准确、实时地检测出三相电流中的谐波电流及无功电流，可为抑制谐波和无功补偿提供可靠的谐波及无功电流分量。

In order to let the active power filter could be used in 3-phase 4 wires circuits, a new method of harmonics detection is given in this paper, which is based on p-q method and ip-iq method of the instantaneous reactive power theory. This method remove the zero current.

综合运用瞬时无功理论中的p-q法和法，提出了一种新的基于瞬时无功理论的有效的三相四线制谐波检测新方法，此方法能将三相电流中的零序电流剔除。

First, this paper lists formula of active power by analyzing the composing of instantaneous power, then discusses the effect of prefilter to electric energy metering, how to measure electric energy in transient condition, and the influence of load type to the conversion of electric energy.

本文首先分析了瞬时功率的构成，得到有功功率的公式，接着探讨了前置滤波器对电能计量的影响、暂态情况下的电能计量问题和用户类型对电能转换的影响，最后对有功计费提出了一些建议。

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。

Unlike most of the existing schemes, this paper presented a novel quasi direct power control method for PWM rectifier in stationary frame based on instantaneous power theory.

通过分析电压型PWM整流器的瞬时功率，在两相静止坐标系下提出一种新型的准直接功率控制策略。

Limits of technical index frequency: 100kHz~50GHz, depend on probe power limits:- 70~+44dBm(100pW~25W), depend on probe power probe: As compatible as probe of HP8480 series power dynamic limits: 50dB, 10dB pace takes indication unit: Absolute power: W, DBm; Relative to power: Per cent, DB resolution: In resolution of logarithm mode optional 0.1, 0.01 with 0.001dB; 1% what perhaps be complete scale in linear mode resolution, 0.1% with 0.01%.

技术指标频率规模：100kHz~50GHz，取决于探头功率规模：-70~+44dBm(100pW~25W)，取决于探头功率探头：与HP8480系列功率探头兼容动静规模：50dB，10dB步进显示单元：相对功率：W，dBm；相对功率：百分比，dB 分辨率：在对数模式可选择的分辨率0.1，0.01和0.001dB；或者在线性模式分辨率为全刻度的1%，0.1%和0.01%。

In order to improve the power quality of distribution network system, one of the most effective methods is reactive power compensation. In this paper, the Distribution Static Synchronous Compensator for reactive power compensation was studied, and then the digital controller based on One-cycle control was designed. The waveforms of experimental device based on DSTATCOM of one-cycle control were given in this paper. It can be seen from the results that the fluctuation of DC capacitor voltage is lower, the dynamic response speed of DSTATCOM providing or absorbing reactive power is fast, and the accuracy of steady-state compensation can achieve the requirements of reactive power compensation in engineering basically

为了提高配电网系统的电能质量，对无功功率进行精确补偿是非常有效的方法之一；本文研究了配电网静止同步补偿器用于无功补偿，并设计了单周控制的数字控制器；文中给出了基于单周控制的DSTATCOM无功补偿试验装置工作过程中的波形曲线，从试验结果可见，本文设计的单周控制DSTATCOM无功补偿装置的直流侧电容电压在工作过程中波动较小，装置发出或者吸收无功功率的动态响应速度较快，稳态补偿精度基本能够达到工程中无功补偿的要求。

a kind of design project of multifunction electric power quality gauged instrument based on virtual instrument is put forward in this article.this system integrates virtual instrument programming and power electronics together,to realize diverse signals of current electric power quality field allin one.the integrated signal generator unit which carries out the collection of high speed digital data,d/ a conversion and analog output in four channels,unsymmetrical synchro control fifo etc.by fpga are introduced,the flow of electric power system various signal which generates by vc programming is elaborated,and the structural design of signal amplification unit is analysed.the experiment text result shows that this gauged instrument has attained current advanced high grade of accuracy and it will accelerate the steps of electric power quality calibration because of its accuracy and versatility.

摘 要：提出一种基于虚拟仪器技术的多功能电能质量标定仪的设计方案，采用虚拟仪器编程技术和电力电子技术相结合实现集目前电能质量领域的多样信号于一体。介绍采用fpga实现高速数字量采集、d/a转换及4通道模拟量输出、非对称同步控制fifo等的集成信号发生单元，阐述利用vc编程实现的电力系统多样信号的产生流程，分析信号放大单元的结构设计。实验测试结果表明该标定仪达到目前先进的高精度等级，由于其准确性和多功能性将加快电能质量标定的步伐。

Based on varying process of generator terminal parameters after excitation fault, shortages of excitation protective principle of static stability boundary and asynchronous impedance boundary are analyzed. It proposed that excitation fault research relates to large-disturbance stability. Because dynamic power-angle character of generator after excitation fault is non-sinusoidal, there are differences between dynamic power-angle character and static state power-angle character. So it isn't ideal to protective operation result based on small-disturbance stability and static stability boundary criterion. At the same time, it proposed that asynchronous boundary impedance criterion is a constant reactive power circle moving adown j Xd′. It can ensure complete loss-of-excitation generator measuring impedance enter into the circle, but can't ensure the other condition measuring impedance including impossible losing synchronism enter. So loss-of-excitation protection would be maloperation when system voltage drops short and recovers or generator rejects load.③Based on stability principle, it puts forward setting conditions and calculation method of generator loss-of-excitation protection by direct measuring power-angle.

以励磁故障后发电机端的相关参数的变化为基础，通过对以静稳定边界和异步阻抗边界作判据的两类三种现行励磁保护在原理上存在的缺陷分析，发现：励磁故障是一个大干扰稳定性问题，励磁故障后的发电机的动态功角特性与静态功角特性有很大的差异，已远非正弦曲线，因此基于小干扰稳定性原理、以静稳定边界作判据的保护必然动作不理想；异步边界阻抗判据是一个下移j Xd′的等无功阻抗圆，它可以保证完全失磁后的发电机测量阻抗能进入该阻抗圆，但不能保证完全失磁之外的其它状态不会进入该阻抗圆，因此在系统电压短时下降或发电机突然甩负荷等情况下可能启动该保护使之误动。

We got alerted a couple of times while we were down south that HETs were on the way to bring us back up north because things were going to go hot again, but it was just rumors.

南下的途中我们不只一次得到警告说重型装备运输车将拉着我们重新北上，因为局势正在变得重新紧张起来，但这只是谣传。

It's the one where they find the ghost in the salt mine.

这一集是演他们在盐矿找到鬼