光学电压传感器分压结构的缺陷及改进方法

现有的光学电压传感器多基于光功率检测模式,其测量范围与测量灵敏度受到电光晶体半波电压的限制。纵向调制的多片晶体叠层结构可以解决半波电压限制的问题,但仅适用于1 000 kV电压等级。此外,仿真结果表明这一结构中晶体内的电场分布极不均匀,受震动与热胀冷缩等因素的影响,光路或晶体的相互位置易产生偏移而引入积分电压误差。文中以110 kV电压等级为例,对多片晶体叠层结构进行了改进,简化了传感系统的结构,并将MgTiO₃陶瓷按照一定的要求安装在锗酸铋(BGO)晶体的外部以改善晶体的内电场分布,可以把积分电压误差从0.275%降低至0.01%以下。改进后的结构可用于各种电压等级。最后,通过实验验证了新方法的有效性。     

自愈光学电压传感器

为解决光学电压传感器测量精度的温漂问题,提出采用增加基准测量源的方法,根据对基准源的测量结果来调整实际测试结果,从而实现了对传感参数的实时自动补偿。应用该方法设计了自愈光学电压传感器,并进行了精度检测。检测结果表明:在常温下,自愈光学电压传感器的线性度可达0.2级;当环境温度引起工作光强波动或传感参数漂移时,自愈光学电压传感器的测量精度比补偿前有大幅提高。该方法原理简洁,容易实现,为高性能光学电压传感器的设计提供了新的解决思路。     

配电网故障指示器中电压测量的研究

配网故障指示器中电压的准确测量是故障识别的重要依据之一。仿真分析了配网不同接地方式下各种接地故障的电压特征,故障相或非故障相的电压变化特征可作为故障指示器故障识别的判据之一。设计了一种基于故障指示器机械结构,利用耦合电容分压的电压传感器,分析了配网线路对地架设高度不同及温度变化对电压传感器测量结果的影响。样机测试结果表明传感器在测量范围内的线性误差在±3. 8%之内,其作为电压变化特征的识别准确度足够。     

光电集成强电场测量系统及其应用研究

为研发高性能强电场测量系统,在分析高压电场测量的特殊要求后,介绍了光电电场测量系统的基本原理、最新进展及其在高压测量领域的优势。通过对光电集成电场测量系统及传感器体系结构、关键参数的分析,研制了一种光电集成强电场传感器并测量它的输入输出特性。用研制的测量系统测量棒板间隙击穿过程冲击电场与复合绝缘子工频场,证明光电集成电场测量系统在高压测量研究领域的广阔应用前景。     

750kV交流系统用MOA电位分布试验分析

随着电压等级的不断升高,无间隙MOA各电阻片对地的杂散电容对其运行电压下的电位分布的影响也不断增大。对MOA的电位分析尤其是试验分析在生产实践中就显得尤其重要。笔者采用试验的方法对750 kV交流系统用MOA的电位分布进行分析。首先,介绍了自主研发的光纤测量系统,该系统由电流传感器、光纤、信号处理单元和计算机4部分组成。经过实验室校正取得了良好的结果,完全能满足工程需要。接下来,采用该测量系统对750 kV交流系统用MOA在运行电压下进行试验,取得了电流分布图,经过简单的处理,转换为电位分布图。最后,采用有限元分析软件ANSYS进行理论计算,将实测结果与计算结果进行比较,二者在反映电位分布趋势上取得了良好的一致性,证明了该试验方法的有效性。     

实现线性测量的光学电压传感器设计

设计了一种采用径向偏振光栅实现线性测量的光学电压传感器。将光学晶体的电光相位延迟角转化成环形光斑的同步旋转,由图像转换器将环形光斑转换为条形光斑,通过图像采集系统定位条形光斑暗纹的中心位置来获得被测电压值。应用琼斯矩阵证明了光斑暗纹中心位置与晶体电光相位延迟角之间的线性关系,给出了计算方法,并给出了锗酸铋(BGO)晶体和铌酸锂(LN)晶体的实验验证。结果表明该光学电压传感器的测量模式与光强无关,可直接测量172°的电光相位延迟角,测量误差小于0.5%,实现了对电压的线性测量。     

特快速暂态过电压光学测量系统的设计

提出一种应用Pockles效应的特快速暂态过电压(VFTO)光学测量方法。通过光学敏感头感应一次VFTO信号,并将电压的变化信息通过光缆传输至电气单元进行解析,最终得到实际电压。该传感器采用光学测量方式,具有可靠性高、抗干扰能力强、测量精度高、测量频带宽的优点。设计制作的新型光学传感器的低频截止频率低于10 Hz,高频截止频率高于1 GHz。对隔离开关操作所引发的VFTO进行了测量试验,通过同步触发装置同时采集两侧安装的光学传感头和电容式传感头信号,对比验证了VFTO光学测量方法的可行性。试验结果表明:光学测量方式与电容式测量方式均反映了刀闸分合闸的过程,2种方式的分合闸持续时间测量结果吻合较好;电容式测量方式测得的VFTO振荡幅度明显小于光学方式的测量结果,光学测量方式在高频段性能要优于电容式测量方式。     

全光纤电流传感器的原理及应用

全光纤电流传感器在高压电网中常用作监测保护和计量,具有重要的实际工程价值,且容易解决高压绝缘和高频电流的测量难题.详细介绍全光纤电流互感器的原理、结构和技术性能.     

Remote sensing system for spatial electric field strength using free space light transmission

Most of the breakdowns in an electric power system are caused by lightning to the tower used for high‐voltage transmission wires. To avoid accidents due to lightning, it would be desirable to develop a measurement system for the spatial electric field distribution around the tower. We have developed a new system that can measure the electric field around the steel tower for electric power transmission by using an optical electric sensor. In conventional methods, the sensor is generally illuminated by light transmitted by optical fibers. On the other hand, the new measurement system illuminates the Pockels sensor directly by using a laser to measure the far electric field. Furthermore, our newly proposed feedback system makes it possible to measure the spatial electric field without concern for the change of Pockels sensor's operation point influenced by temperature change. This system is applicable as a remote sensing system to monitor the spatial electric field around a high‐voltage transmission line. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 162(2): 10–19, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20552     

Accurate voltage measurement with electric field sampling usingpermittivity-shielding

This paper introduces permittivity-shielding which enables the measurement of voltage with very few electric field sensors. Voltage sensor designs using permittivity-shielding can exploit existing optical sensor technology without the need for the expensive and potentially hazardous insulation found in many modern optical voltage transducers (OVTs). Numerical simulations demonstrate that a voltage sensor consisting of 100 MΩ shielding and six electric field sensors, or less, mounted inside an "off-the-shelf" stand-off insulator can achieve IEC 60044-2 0.2 metering class accuracies (<0.2% magnitude error and <10 minutes phase error) even in the presence of strong stray field effects     

Development of a laser wavefront sensor for measurement of discharges in air

A laser wavefront sensor of the Shack‐Hartmann type capable of simultaneous measurement at two wavelengths was constructed. The sensor uses a single optical path, and is suited for applications such as high‐voltage discharges in air, in which large insulation distances are necessary. The sensor was used to detect optical path differences due to an impulse discharge in air across a needle–plane electrode gap of gap length 17 mm. Optical path differences were measured at laser wavelengths of 532 and 1064 nm at 1.6 µs after insulation breakdown across the gap. From the difference in optical path differences at the two wavelengths, a line‐integrated electron density distribution in the direction perpendicular to the gap was obtained near the high‐voltage electrode. The distribution had a peak value of 1.4 × 10²⁰m^?2 and a full width at half maximum of 4.4 mm. Because of the coverage of a large observation area including the entire gap, the spatial resolution was 1.4 mm, which was inadequate to obtain the precise form of the electron density distribution. However, the results show the possibility of applying laser wavefront sensing to electron density measurement. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 146(4): 10–17, 2004; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10247     

高电压环境下的温度测量及补偿方法研究

针对高电压、强磁场环境中的温度测量,提出了基于光纤温度传感器的温度测量方案,设计了新型的光纤温度传感器,通过双波长光源和补偿回路的设计,提高了测量精度和稳定性。理论证明和多次试验验证表明,该方案能够实现精度较高的温度测量,并且具有绝缘性好、抗电磁干扰能力强、成本低、体积小、便于安装等优点。     

Experimental proof of voltage‐current waveform sensor output of resin molded type for measurement of power factor and harmonics in general power distribution system

We have proposed a voltage‐current sensor of resin molded type for measurement of the power factor and harmonics. To understand the characteristics of the conventional prototype sensor and the problems of its practical use, we conducted a finite element analysis. Problems involving the cost and practical usage of the sensor were identified. Therefore, we have redesigned the prototype sensor, incorporating the current sensor designed on the basis of the FEM and a ready‐made voltage sensor. In this paper, we describe feasibility field experiments with the present sensor in a practical 6.6‐kV distribution system and show that the sensor can measure the power factor and harmonics of horizontal and vertical power line systems successfully. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 178(3): 1–10, 2012; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21213     

基于保偏光纤模间干涉的光学电压互感器

为了满足高压及超高压电网对新型电压互感器的迫切需要,研究了一种基于保偏光纤模间干涉原理的高压电压互感器。用缠绕了保偏光纤的石英晶体圆柱作为电压传感头,被测电压通过石英晶体的逆压电效应来调制保偏光纤中2个低阶线性偏振模间的相位差,进而改变模间干涉输出光强的分布,通过探测模间干涉输出光强实现对被测高电压的测量。系统通过调整压电陶瓷的驱动电压使得模间干涉静态相位差为正交状态,并采取引入参考光路的方案剔除光源强度波动对测量精度的影响。实验研究结果表明,该互感器在额定被测电压附近能够达到0.2%的测量精度,能够同时反映被测高压的幅值和相位信息,满足高压测量领域对暂态变化的测量要求。     

Calorimetric measurements of optical signals in electrostaticdischarge studies

A method based on calorimetry and an instrument are described for the absolute measurement of the energy contained in optical radiation, especially in the optical signatures of electrostatic discharge. The optical emission of a spark gap, comprised of two stainless-steel spheres, was collected by an optical condenser system and focused on the calorimeter sensor. The system was calibrated using a set of light-emitting diodes and tested using either single-pulse discharge or a continuously operating optical source. The calorimeter system detectivity, in terms of output voltage related to the input energy, was determined to be 4.3 × 10⁷ V·J^-1 and its detection limit was 2.3 × 10^-13 J. The system has application for nonintrusive characterization of optical emissions associated with discharge events     

Design and research of a three‐phase voltage sensor based on D‐dot principle

In the design of three‐phase D‐dot voltage sensor based on electric field coupling, both effects of both the adjacent phase electric fields and distribution parameters on measurement should be taken into consideration. This paper builds a simulation model and a physical measuring system of a three‐phase sensor, measures the effect of the distribution parameters by the simulation model, and finally finds the transfer function between the input and output voltage signals of the circuit. The measured voltage waveforms and parameters can be reflected by the physical measuring system. Our results provide a theoretical basis for the design of a three‐phase D‐dot voltage sensor. And the measuring system can achieve multipoint synchronous acquisition and ensure less distortion. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

采用LED光纤传感器的绝缘子串泄漏电流测量方法

测量绝缘子串的泄漏电流是目前监测输电线路绝缘子串表面污秽状态的主要手段之一,然而由于输电线路环境的复杂性,常常会伴生出大量的电磁干扰,会在泄漏电流的采集源头产生噪声从而导致采集失真。为提高传感器测量绝缘子泄漏电流的抗干扰能力和准确度,采用廉价稳定的光学器件—发光二极管(light emitting diode,LED)设计并制作了1套光纤传感器装置,利用光电转换和光信号的稳定性,以3片XP-160绝缘子串为试验对象,取盐密为0.05～0.2mg/cm2,在同一相对湿度(85%)下,采用逐渐加压法监测绝缘子串的泄漏电流。经试验验证,该光纤电流传感器可以实现选择性测量泄漏电流的正半周波或者负半周波,经过改进使用差分电路后可以实现测量全波泄漏电流,其零休时间<1ms,波形响应时间<0.1ms,测量电流的灵敏度达到40V/A,线性拟合度均>99.94%,频率响应在1～10kHz范围内,可以满足对泄漏电流测量的基本要求。     

Development of high voltage harmonic measuring instruments for distribution systems using optical voltage sensor and current sensor

Application of an optical measuring technique was attempted in order to develop harmonic voltage and current measuring instruments for distribution systems. To develop the harmonic voltage measuring system using a Bi₁₂GeO₂₀ crystal as a sensing Pockels cell for high‐voltage distribution lines, zinc oxide elements were adopted as a voltage divider. Also, an optical current sensor system was improved on the harmonic current measuring system using an R₃Fe₅O₁₂ film as a Faraday device. In practical three‐phase distribution systems, the developed high voltage harmonic measuring devices using the optical voltage sensor and current sensor were compared with conventional harmonic analyzers for low voltage. As a result, it was confirmed that the developed high voltage harmonic measuring devices had satisfactory characteristics for practical use. © 1999 Scripta Technica, Electr Eng Jpn, 128(4): 84–93, 1999     

基于模间干涉的全光纤电压传感器设计

介绍了一种新型的光纤电压传感器结构和工作原理,分析了系统中椭圆芯双模光纤的传输模式和模间相干光斑的变化,采用熔接的方式进行相干光接收来获得正交相位漂移信号,根据模间群折射率差与光程差的关系设计调整光纤的长度,依据石英晶体和空气的绝缘强度进行传感光纤匝数设计,讨论了含源零差探测法的相位跟踪原理,给出了相位检测框架图及实验结果,分析表明该设计方案能达到相位跟踪的目的。     

基于光学电压互感器稳定性的分析与研究

在69KV～765KV的供电系统中,光学电压互感器可提供模拟量或数字量输出,适应电力系统微机化、网络化、保护和测量智能化的要求,且体积小、重量轻、无爆炸危险,是一种理想的、新型电压互感器。但受BGO晶体双折射、传感器结构以及环境温度等的影响,使光学电压互感器的稳定性下降,因此要采取有效措施,提高其工作稳定性,保证电力系统的正常运行。