电能

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。

In energy loss calculation, a method named equivalent resistance is introduced.

电能损耗计算中运用等值电阻法计算电能损耗，它将配电网中由线路和变压器绕组产生的可变损耗等价为两个等值电阻上的损耗，同时根据实际电网中负载的变化对这两个电阻进行修正，最后计算出网络的电能损耗。

For increasing the electric power quality of power system,a power quality management system based on electric power Wide-area Net is established,which is a classified and destributed management system,divided into three layers,that is terminal layer;local net power quality data management system;and central data management system,the WAN is used as a communication medium between layers.

摘 要：为了提高电力系统供电的电能质量，江苏电网已建立了一套网络型电能质量管理系统。该系统是一个分层、分布管理系统，系统分成三层，即监测终端、地区电网电能质量数据管理系统和中心数据管理系统，以广域网为层间通信介质。

Developed a computer controlled energy utilization ratio measuring system with which every part's energy consumption in a EDM system could be tested at the same time, including general input, pulse generator and spark gap, dielectric system and servo system.

该系统可以同时测试一个EDM系统中各部分的电能消耗，包括总的输入电能，消耗在脉冲电源和火花间隙中的电能，以及工作液循环系统，伺服系统等部分消耗的电能。

The calculation formula of the reactive power is concluded by means of the Fourier analysis method. The physical meaning of every item in formulaes is analysed. Finally the article analyses the influence of the reactive power in the nonsinusoidal condition on two primary reactive energy measurement technology. The analysis show that reactive power definition produces which in the standard IEEE100-1996, having a bigger deviation with two kind of reactive energy measurement technology to measure reactive energy.

本文采用傅立叶分析方法，导出非正弦电路的无功功率的计算公式，分析了公式中每一项的物理意义，并就非正弦无功对目前主要的两种无功电能计量技术（电磁感应式无功电能计量技术，电子式无功电能计量技术）的影响进行了理论分析，得出在IEEE 100-1996标准给出的无功功率定义下，用两种无功电能计量技术测量无功均会产生较大偏差的结论。

The physical meaning of every item in formulae is analysed. Finally the article analyses the influence of the reactive power in the nonsinusoidal condition on two primary reactive energy measurement technology. The analysis show that Reactive power definition produces which in the standard IEEE100-1996, Can have a bigger deviation with two kind of reactive energy measurement technology to measure reactive energy.

并就非正弦无功对目前主要的两种无功电能计量技术（电磁感应式无功电能计量技术，电子式无功电能计量技术）的影响进行了理论分析，得出在IEEE100-1996标准给出的无功功率定义下，用两种无功电能计量技术测量无功均会产生较大偏差的结论。

As the use of digital technology, time-sharing billing energy meter, prepaid energy meter, energy meter multi-user, multi-function watt-hour meter debut one after another, and further use of electricity to meet the scientific and rational use of electricity demand; electromechanical watt-hour meter is induction Watt-hour meter as the base table, through the acquisition of electronic circuit of the principle of pulse power meter measurement.

由于应用了数字技术，分时计费电能表、预付费电能表、多用户电能表、多功能电能表纷纷登场，进一步满足科学用电、合理用电的需求；机电式电能表是用感应式电能表作为基表，通过电子线路采集脉冲的原理进行计量的电能表。

In this paper ,the influence of harmonic to the accuracy of potential transformer and current transformer is studied firstly, and then through some experiments, the new equipment-multifunctional metering of electric energy equipment based on virtual instruments technology and traditional induction Watt\|hour meter to measure the power at different harmonic situations.

首先探讨谐波对仪用电压电流互感器精度的影响，然后通过具体实验，利用新研制的基于虚拟仪器技术的多功能电能计量装置与传统的感应式电能表在不同的谐波条件下同时计量电能，对二者结果进行对比分析，得出谐波对感应式电能表计量影响的准确数据，并总结其规律。

Then the error sources of the reaction type and electron type electric energy mete were analyzed and the theory analysis result through the concrete test have been proved. At last, the main conclusion has been drawn. When the induction type electric energy meter measures harmonics energy, the negative error characteristic appears. The higher the frequency of harmonics is, the greater the error is. The electron type electric energy meter can measure harmonics energy accurately in general cases. Except thermo-electrical conversion type electron type power meter, reaction type and electron type electric energy meter can measure direct current power.

本论文通过分析感应式和电子式电能表的工作原理推导出了电能表计量电能的数学模型；分析了感应式和电子式电能表的误差来源以及谐波对计量的影响，并通过具体的试验对理论分析结果进行了验证；得出了如下谐波对电能表计量影响的主要结论：感应式电能表计量谐波电能时，呈现负的误差特性，谐波频率越高，误差越大；电子式电能表在其频响范围内可以准确计量谐波电能。

In order to reduce the production process mill system power supply system of the impact of power quality,improve the stability of equipment to meet national standards and power quality of the electricity sector of the target requirements,in the rolling mill factory production lines to install a set of 30kv side bus SVC.It restrained the molestations of power plants lines,make important roles of improve power quality,improve power factor,and level off the run level of electric web.

为了减轻轧机系统生产过程中非线性冲击负荷对供电系统电能质量的影响，提高设备运行的稳定性，满足国家标准和电力部门对电能质量指标的要求，在生产线30kV母线侧，装设了一套静止无功补偿装置，结果是把生产线对供电系统电能质量的干扰抑制到一个较低水平，对改善供电系统的电能质量，提高功率因数，稳定电网运行水平起到了极其重要的作用。

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％。