针板型电晕稳定开关的电晕稳定性

设计了一款可用于触发和自触发的针板型电晕稳定开关,其中针电极直径为2 mm,主间隙距离为10 mm,触发间隙为5 mm。通过静电场的模拟得知其场强的不均匀系数大于7,并且通过大量实验数据得出：开关起晕电压和击穿电压分别为6.8 kV和19.3 kV,由此得知电晕稳定开关的电晕稳定因子为0.55,这说明开关具有较好的电晕稳定性。     

针板型电晕稳定开关的电晕稳定性

设计了一款可用于触发和自触发的针板型电晕稳定开关,其中针电极直径为2 mm,主间隙距离为10 mm,触发间隙为5 mm。通过静电场的模拟得知其场强的不均匀系数大于7,并且通过大量实验数据得出:开关起晕电压和击穿电压分别为6.8 kV和19.3 kV,由此得知电晕稳定开关的电晕稳定因子为0.55,这说明开关具有较好的电晕稳定性。     

高压电晕特性的研究

介绍应用图像增强技术解决高压电晕观测中存在问题的实验原理和依据,分析高压电晕图像的特性,讨论利用图像增强技术研制的高压电晕观测仪器的特点,举例说明该系统在输电导线电晕放电特性研究中的应用,最后指出图像增强技术在高压电晕观测中的应用前景。     

主变室外部声场分布主要影响因素对比研究——以220kV户内变电站为例*

为了解决城市户内变电站噪声对环境的影响问题,研究户内变电站主变室外噪声分布状况,该文采用RAYNOISE软件对220 k V户内变电站不同类型的门窗和进风口进行模拟分析,主变室内放置1台主变压器。模拟结果显示,是否设置隔声门对室外声场的影响不大,而消声百叶对室外声场的影响较大,比普通百叶的降噪效果高3～4 d B;同时设置隔声门和消声百叶的降噪效果比普通百叶和金属门高5～6 d B。该文通过一系列的模拟计算,推导出了户内变电站主变室外部三维空间的噪声预测模型,以期为变电站的噪声控制和改造工程提供科学指导和技术支持。     

电晕放电演示仪的研制与应用

介绍了一种新的教学演示仪器－电晕放电演示仪。     

高压脉冲波的电晕电流测量方法

在观测高压脉冲电晕放电时，因脉冲电晕电流中除了有离子电流外，还有位移电流，并且位移电流是比离子电流大2—3个数量级，因此，受到位移电流很大影响，给测量工作带来很多困难，本文介绍一种对高压脉冲电晕电流的测量方法，它能解决位移电流对电晕电流的波形测量的影响，能定量的测出离子流的平均电流，离子电流的逐值，离子电流峰值到接收极的时间等参数．一、实验装置本实验装置如图1，它是由高压脉冲电源”’、电晕线、金属屏蔽网、接收极、直流电源、电容C、取样电阻等组成．二、出且原理与方法高压脉冲电源能方便地改变高压脉冲输…     

一种抗干扰变电站1/3倍频程噪声测量方法*

针对变电站噪声测量容易受外界干扰的问题,提出了一种抗干扰变电站噪声测量系统实现方法,利用最小值控制递归平均算法实时估计每个时频点变电站噪声存在概率,再综合成每个1/3倍频程中外界干扰信号存在概率;对干扰信号存在的1/3倍频程,不进行1/3倍频程噪声更新,从而避免外界干扰信号对变电站噪声测量的影响。仿真结果证明,该方法可以有效减小瞬态干扰对变电站噪声的影响。     

120 kV下常压空气纳秒脉冲电晕放电特性

使用上升沿15 ns、脉宽30~40 ns的重复频率纳秒脉冲电源对120 kV下大气压空气中管-板电极结构电晕放电进行了实验研究,通过电压电流测量、放电图像拍摄和X射线探测分析了纳秒脉冲电晕放电特性。结果表明:纳秒脉冲电晕放电中存在X射线辐射,但辐射强度较弱,X射线辐射计数随着气隙距离的增大而减少,随着脉冲重复频率的增大而增多;放电空间的残余电荷加强了下一个脉冲到来时的局部电场,从而导致高重复频率下易于出现分散的电晕通道。     

120 kV下常压空气纳秒脉冲电晕放电特性

使用上升沿15 ns、脉宽30~40 ns的重复频率纳秒脉冲电源对120 kV下大气压空气中管-板电极结构电晕放电进行了实验研究,通过电压电流测量、放电图像拍摄和X射线探测分析了纳秒脉冲电晕放电特性。结果表明：纳秒脉冲电晕放电中存在X射线辐射,但辐射强度较弱,X射线辐射计数随着气隙距离的增大而减少,随着脉冲重复频率的增大而增多;放电空间的残余电荷加强了下一个脉冲到来时的局部电场,从而导致高重复频率下易于出现分散的电晕通道。     

气体介质对多间隙气体开关电晕均压与自击穿特性的影响

快脉冲直线变压器型驱动源（FLTD）是近年来快速发展的新型脉冲功率源技术,多采用多间隙气体开关作为开关器件。电晕均压措施有利于提升开关击穿性能,但不同气体中电晕放电有显著区别。本文首先研究了空气中针电极对单间隙电晕放电特性的影响,确定了电晕针电极的尺寸,之后研究了N₂,CO₂,SF₆/N₂混合气体、C₄F₇N/N₂混合气体中的电晕放电特性,研究了电晕均压6间隙气体开关击穿电压及其稳定性随气体种类和气压的变化规律。实验结果表明,N₂中电晕电流较大且不稳定,空气中电晕电流比N₂中低,且电晕放电较为稳定,微量强电负性气体加入会极大降低电晕放电电流。当采用空气和N₂作绝缘介质时,气体开关击穿电压随气压升高线性增加,但存在低值击穿,微量强电负性气体混合N₂可显著提升击穿电压的稳定性。1%SF₆/99%N₂混合气体在0.18 MPa时,击穿电压约为197.33 kV,标准偏差占击穿电压比例为1.50%,1% C₄F₇N /99%N₂混合气体在0.15 MPa时,击穿电压约为190.42 kV,标准偏差为0.55%。这表明,微量环保替代气体C₄F₇N与N₂的混合气体对于提升多间隙气体开关击穿电压稳定性有显著作用。     

墨粉灌装车间噪声测试分析与控制

本文应用峰值频率声压级对比方法并结合相干分析技术对某墨粉灌装车间主噪声源进行了诊断，分析了声源特性，在此基础上提出了经济合理的治理措施，实施后取得了满意的结果，车间噪声达到了相应的国家标准。     

Comparative study of two different measuring methods for corona current pulses

Based on a designed coaxial cylindrical corona discharge platform, this paper compares two methods for the measurement of corona current pulse, namely from cage side and conductor side both at low potential. It is found that the corona pulse can be obtained from both methods and the waveform of the current pulse is highly dependent on the sampling resistor. Then two simplified models are proposed to interpret the experimental results and the relationship between the two measurement methods. It shows that the key point in accurately measuring the corona current pulse is the selection of suitable sampling resistor.     

Experimental investigation and modeling of corona characteristics under lightning impulses

An experimental study is conducted on the corona characteristics under lightning impulses. The charge-voltage characteristics, i. e. the Q-U curves, are measured in a corona cage. The impulse waveshapes are varied to investigate their influence on the Q-U curves. Meanwhile, a corona model is proposed to compute the Q-U curves. The ionized zone is simplified as a cylindrosymmetric geometry and a one-dimensional subdivision is made in the radial direction. The Q-U curves can be given by performing an efficient computational procedure. The computed results are compared with the measured ones to check the validity of the model.     

Influence of the corona-wire diameter and length on corona discharge characteristics of a cylindrical tri-axial charger

In this paper, the corona discharge characterization in terms of current–voltage relationships of a unipolar cylindrical tri-axial charger on the effects of the corona wire diameter and length have been experimentally studied and discussed. A commercial computational fluid dynamics software package, COMSOL Multiphysics™, was used to predict the electric field distribution in the ion generation and charging zones of the charger and the ion penetration through the perforated screen opening on the inner electrode of the charger. It was found from experimental results that both positive and negative charging currents in the charging zone of the charger increased with increasing corona and ion-driving voltages. At the same corona and ion-driving voltages, both positive and negative coronas were decreased with increasing diameter of the corona-wire. Compared with the corona-wire of 22 mm in length, the magnitude of both positive and negative charging currents were markedly higher for corona-wire of 11 mm in length at the same corona voltage. It was found that the charging currents for negative coronas were about 1.2 times higher than those positive coronas at the same corona and ion-driving voltages. Numerical results of the electric field distribution and the ion and charged particles migrations in the discharge and charging zones of the charger is correlated to have the same direction with the experimental results of the current–voltage relationships. Also, this can be used to guidance in describing the electric field distribution and the behavior of ion and charged particle trajectories that cannot be seen from experiments in order to improve the applicably design and refinement of a unipolar cylindrical tri-axial charger.     

Modeling of corona under positive lightning surges

A novel corona model for predicting the corona characteristics under positive lightning surges is proposed. The ionization process is described by a series of successive generations of electron avalanches. A simplified method is presented for computing the electric field in the ionization zone. With a discrete treatment for the ionization process in time and space, the proposed model computes the total charge of corona from the applied surge voltage and so the q–u curves can be obtained. A laboratory measurement of q–u curves is also made by a coaxial cylindrical electrode to check the validity of the proposed model.     

噪声主动控制研究的发展与动向

本回顾了噪声主动控制的典型设计方法和常见的算法,结合当前较新的鲁棒控制方法,指出今后噪声主动控制的一些发展动向,为这一技术的实用性提供借鉴。     

Temperature and humidity behaviour of a corona based smoke sensor

Ionization smoke sensors are amongst the best smoke sensors; however, the little radioactive source that they include is no longer desirable since recycling gets more complicated. In this paper we discuss an electrostatic system in which corona phenomena is used to generate the ions needed to smoke detection. We show how the velocity of ions is reduced in our system for a better interaction between smoke and drifting ions. Influence of smoke, temperature and moisture is studied. It is shown that the proposed sensor has a good sensitivity compared with conventional ionic and optical smoke sensors.     

INTER-NOISE 95会议噪声控制进展综述

本文介绍了美国加州ＮＥＷＰＯＲＴＢＥＡＣＨ召开的１９９５年国际噪声控制工程会议简况，并根据会议报告及论文集，对当前国际上噪声控制学科的进展作出综述。     

Influence of corona on strike probability of grounded electrodes by high voltage discharges

This paper presents the results of an investigation into the influence of corona formation processes at the tips of grounded rod electrodes on the probability of those rods being “struck” by high-voltage discharges. Experiments simulating the final stage of the attachment process were carried out with a composite voltage comprising a simultaneously applied impulse and DC potential of different levels to grounded rod electrodes simulating lightning rods, featuring either a spherical or pointed (conical) tip. The experiments show that corona does not influence the probability of the electrode being struck until a critical electric field (EF) strength is reached.