基于模间干涉的光学电压互感器的设计

针对电力工业向高电压,大容量的输配电电网发展的需求,提出了一种新型的光学高压电压互感器.该方法是根据保偏光纤模间干涉原理,采用石英晶体的逆压电效应的方法.该光学电压互感器的工作原理是在圆柱形石英晶体上施加交流电压使其产生压电形变,使缠绕在圆柱表面的椭圆芯双模光纤中的LP<'01和LP<'11模的相位差发生变化,最终得到被测电压.根据群模态折射率差与归一化频率的关系,对光纤的参数进行了研究.通过实验对该互感器的设计进行了可行性研究.实验结果表明,本案具有较好的精度和线性度,为光学电压互感器的研究提供了理论基础.     

电压互感器示值误差测量结果的不确定度评定

一、测量条件与方法 依据JJG314—194《测量用电压互感器》检定规程，使用0．01级HJ10型标准电压互感器作标准，变比为10000V／100V：被测电压互感器型号为HJ47／4．准确度为0．05级．变比为10000V／100V。测量时环境温度为＋25℃，相对湿度为60％。     

1000kV特高压长治站1000kV电容式电压互感器浅析

1000kV特高压长治站1000kV电容式电压互感器足目前国内电压等级最高的电容式电压互感器，在世界范围内处于领先地位，由桂林电力电容器有限责任公司负责研制生产。本文从1000kV特高压艮治站1000kV电容式电压互感器原理出发，对本站1000kV电容式电压互感器进行分析与说明，结合常规电容式电压互感器的结构特点及运行中的易发故障，提出1000kV电容式电压互感器在设计及运行管理中需注意的问题。     

电压互感器二次回路断线查找与分析

电压互感器（英文缩写PT）是电力系统中重要设备之一，为继电保护装置提供电压数据，供其对故障分析与判断，然而非电压互感器自身原因引起的PT断线在电力系统中发生较多，严重影响了继电保护装置的可靠运行，由此想谈一下电压互感器与PT断线查找方法和技巧。     

110kV电容式电压互感器的故障分析

本文介绍了电容式电压互感器的结构,常见故障类型及防范措施,并结合实例分析了一起电压互感器的二次电压异常事故。     

浅谈交流高电压的测量方法

高电压的测量在工业领域，尤其在电力系统方面经常遇到，但有时所要测量的高电压常常比现有电压互感器的额定电压高许多，本文正是针对此类问题分析比较其他测量高电压的常用方法。     

电压互感器单相接地指示异常分析

本文了分析电压互感器单相接地故障现象，对我厂北变油建线10kv电压互感器指示异常的原因进行分析。     

电压互感器V-V接线分析

本文主要对电压互感器v—v接线错误进行分析，遇到电压互感器v—v接线不正确时，能找到错误的原因并及时改正进行电费的追补。     

6kV供电系统二次回路电压互感器谐波问题研究

针对太原钢铁有限公司峨口铁矿6kV系统电压互感器二次回路电压异常，理论分析了电压互感器的磁路，研究了电压互感器中性线缺失后电压波形畸变、三次谐波产生机理。通过理论分析和实验验证，中性线接地有效解决了电压互感器谐波干扰问题和实际生产中的供电难题，同时其改进经验和方法在其它变电所得到了推广应用。     

保护用互感器的质量评定

一、前言 传递电流信息或电压信息给保护和控制装置的电流互感器或电压互感器,分别称为保护用电流互感器或保护用电压互感器。在电力系统中使用的电流互感器和电压互感器通常有两个二次绕组,其中一个二次绕组接测量仪表,从测得的二次绕组上的电     

新型智能路灯照明调控系统

路灯照明光源通常是高压钠灯和汞灯,调控设备具有变压与稳压的双重功能,通过控制电路和时控电路,实现最优化的智能控制。智能照明调控装置,通过补偿变压器、多抽头变压器,实现主回路输出电压的增减。智能照明调控设备结合节能产品的优点,并克服存存的缺陷。     

A wide-band active current transformer and shunt

An active current transformer and shunt with high accuracy and wide frequency range is described. The transformer, which uses two three-stage core transformers with two two-stage feedback amplifiers, can be used in the audio frequency band. It has a wide range of current ratio (0.01-1) and can dissipate 10 W in the external burden. If the external burden of the transformer is an AC standard resistor, it becomes an AC current to voltage transducer that can be used in many electrical measurements. The relative uncertainty (3σ) in the current ratio of the new transformer is between (1+j1) p.p.m. to (8+j8) p.p.m. over the frequency range from 40 Hz to 10 kHz     

基于改进型两次平衡对检法的感应分压器自校准方法

介绍了参考电势变压器和指零仪变压器设计原理,分析了屏蔽间泄漏对测量结果的影响;对常规两次平衡参考电势对检法进行了改进,使零平衡和段平衡测量过程中,参考电势和测差电路均可实现等电位保护;对自校准方法进行了推导,校准结果仅与段平衡和零平衡时锁相放大器测量的电压差值相关,与参考电势变压器、指零仪变压器、辅助变压器等的误差无关,屏蔽间泄漏的影响也得到消除。对1kV感应分压器进行了校准实验,并对校准结果进行了测量不确定度分析,其相对扩展不确定度的评估结果为5.4×10^-8(k=2)。     

Positive and negative effects of dielectric breakdown in transformer oil based magnetic fluids

The transformer oil based magnetic fluids can be considered as the next-generation insulation fluids because they offer exciting new possibilities to enhance dielectric breakdown voltage as well as heat transfer performance compared to pure transformer oils. In this study, we have investigated the dielectric breakdown strength of the fluids with the various volume concentrations of nanoparticles in accordance with IEC 156 standard and have tried to find the reason for changing the dielectric breakdown voltage of the fluids from the magnetic field analysis. It was found that the dielectric breakdown voltage of pure transformer oil is around 12 kV with the gap distance of 1.5 mm. In the case of our transformer oil-based magnetic fluids with 0.08% < Φ < 0.6% (Φ means the volume concentration of magnetic nanoparticles), the dielectric breakdown voltage shows above 40 kV, which is 3.3 times higher positively than that of pure transformer oil. Negatively in the case when the volume concentration of magnetic nanoparticles is above 0.65%, the dielectric breakdown voltage decreases reversely. From the magnetic field analysis, the reason might be considered as two situations: the positive is for the conductive nanoparticles dispersed well near the electrodes, which play an important role in converting fast electrons to slow negatively charged particles, and the negative is for the agglomeration of the particles near the electrodes, which leads to the breakdown initiation.     

压电变压器的研究进展

压电变压器利用压电陶瓷材料自身的压电和逆压电效应来实现升降压，同传统的电磁变压器相比较，具有体积小、无电磁污染、升压比随工作频率和阻抗变化的特点。本文详细评述了用于压电变压器的铁电陶瓷材料的电畴特性、性能参数和掺杂改性的方法，以及压电变压器的变压原理、一般等效电路图和各种各样的压电变压器，分析了现阶段压电变压器存在的问题，并展望了压电变压器的发展方向。     

35kV母线电压不平衡原因探究

电网电压不平衡影响电能质量,由于运行方式改变后消弧线圈补偿度不够,导致35kV母线电压不平衡,分析了电压不平衡原因,总结了孝路接地、电压导感器高压高压熔丝熔断、铁磁谐振、电压互感器原因造成35kV母线电压不平衡,并提出了解决办法。     

Effect of transformer type on estimation of financial loss due to voltage sag - PSCAD/EMTDC simulation study

The fault in transmission and distribution lines of the power system creates voltage sag. This paper focuses on estimating the financial loss due to such voltage sags. The transformer in a system has great impact on the estimated number of voltage sags at the sensitive load due to faults in the system. So the financial loss in a system due to sag will be affected by the type of transformer in that system. The financial losses for different types of transformers are calculated in probabilistic manner for different types of load groups. Effect of the transformer in the system, on financial loss due to voltage sag is presented in this paper.     

Precise Calibration of Ratio Transformers

The output voltages of a ratio transformer are defined at open-circuit coaxial connectors. A special socket and a difference transformer, wound with coaxial cable, are used to construct a voltage comparator accurate to 1 in 1010. Subdivided transformers are calibrated by comparing the voltage difference between taps with that of an isolated winding on the same transformer. Two similar transformers are compared directly using two voltage comparators.     

Leakage Inductance and Interwinding Capacitance in Toroidal Ratio Transformers

The small, but often significant, voltage ratio error of a ratio transformer is caused by leakage of magnetic flux and the flow of displacement currents around the windings. A model of the flux leakage pattern within a toroidal transformer is used in conjunction with an analysis of the effect of interwinding capacitances to predict the change of voltage ratio with frequency. Reasonably close agreement between this prediction and measured values of voltage ratio suggest that the theory is essentially correct.     

Theoretical modeling of a thickness-shear mode circular cylinder piezoelectric transformer

We propose a piezoelectric transformer operating with thickness-shear modes of a circular cylinder and perform a theoretical analysis on the transformer. An exact solution from the three-dimensional equations of piezoelectricity is obtained. The output voltage, input admittance, and efficiency of the transformer are determined. The basic behaviors of the transformer are shown by numerical results.