中性点不接地系统中铁磁谐振产生的机理及抑制

在中性点不接地电网中,经常发生由于电磁式电压互感器引起的铁磁谐振现象.文中在分析铁磁谐振机理的基础上,研究了各种铁磁谐振的现象、特征,并对抑制铁磁谐振的各种措施进行了比较,指出4PT接线方式是抑制铁磁谐振的根本措施.     

非有效接地系统中电压互感器防谐振措施研究

铁磁谐振是非有效接地系统中常见的一种现象。HAROLD A. PETERSON建立了铁磁谐振的经典研究模型。本文阐述了谐振产生的机理,对西安电网07年上半年的谐振进行了统计分析,应用PETERSON铁磁谐振经典模型对电压互感器的各种防铁磁谐振措施的原理和其优缺点进行了分析,并对西安电网的此类问题提出了解决方法。     

中压电网铁磁谐振及TV高压保险熔断分析与抑制措施

电力系统运行经验表明,在中性点不接地电网中,经常发生铁磁谐振和电磁式电压互感器(TV)高压保险熔断现象.铁磁谐振和TV高压保险熔断都会严重影响系统的安全、稳定及可靠性.详细地阐述了铁磁谐振产生的机理,并建立了分析铁磁谐振的系统等值电路.在Matlab/Simulink仿真系统中搭建了由分布参数构成的中性点不接地系统的仿真模型,对铁磁谐振现象进行准确仿真.分析了TV高压侧保险熔断的根本原因.针对中压电网中经常发生的铁磁谐振、TV高压侧保险熔断现象.结合TV高压保险熔断的限本原因.对现有的各种防治铁磁谐振措施进行了比较,从中确定了既能抑制铁磁谐振.又能防治Tv高压侧保险熔断的有效措施.     

电磁式电压互感器铁磁谐振消谐措施的研究

在对配电系统电磁式电压互感器铁磁谐振数值仿真的基础上，进一步探讨各种铁磁谐振消谐措施的机理，对其作用效果进行数值计算和分析，所得结果为配电网电磁式电压互感器铁磁谐振的抑制和消除提供理论和实算依据。     

电压互感器谐振过电压分析及预防措施

对电磁式电压互感器引起铁磁谐振的原理进行了分析,对电力系统中发生谐振的分类做了介绍,并将各种谐振对电力系统运行中造成的危害做了阐述。最后,就如何有效预防PT引起铁磁谐振提出了一些限制性措施。     

电力系统铁磁谐振分析综述

铁磁谐振是配电网运行中的一种常见现象,多发生在中性点不直接接地的配电网中。谐振导致的过电压和过电流往往会使电压互感器(TV)过热烧毁,影响线路的正常运行。文章针对铁磁谐振的发生机理及其分类进行了概述,并对当前研究铁磁谐振的各种方法和消谐措施做了总结。     

断路器断口并联电容引起谐振的防止

介绍了铁磁谐振过电压的特点和断路器断口电容与电压互感器产生谐振的成因，并对防止此类谐振的各种措施进行了分析。     

35 kV母线压变零序TV的应用

简述了引起35kV系统铁磁谐振过电压的原因及其危害，总结多年来防止35kV系统铁磁谐振过电压的各种措施，提出采取35kv零序TV防止35kV系统铁磁谐振过电压的最佳措施。同时对35kV母线压变加装零序TV前后和可能出现的各种异常运行状况作了对比分析，并且提出了加装35kV零序TV的具体实施方案。     

配电网电磁式电压互感器谐振过电压抑制方法综述

对配电网中电压互感器铁磁谐振现象进行了研究,指出电压互感器现场运行的主要问题是铁磁谐振过电压。阐述了铁磁谐振过电压的产生机理,对常用消除谐振的措施加以分析对比,提出了防止铁磁谐振过电压的建议。     

Fuzzy理论在电力系统铁磁谐振研究中的应用

根据电力系统铁磁谐振的模糊性,应用Fuzzy理论对电力系统发生铁磁谐振的可能性、影响因素及防止措施进行了研究.这种新方法对补充和完善铁磁谐振问题的研究具有重要的意义.     

A review of ferroresonance in capacitive voltage transformer

Ferroresonance incidences in electrical power system have been commonly regarded as unexplained phenomenon, which is not critical for utility engineers. As a result, research conducted in this area is limited and the awareness on ferroresonance is relatively low among utility engineers. However, as the electrical system evolves, its complexity increases in line with the increasing risk of ferroresonance. As a result, this paper provides a consolidated review on the research conducted on ferroresonance to highlight its importance. This paper covers the fundamental inductor–capacitor pair for ferroresonance initiation and the modes of ferroresonance, followed by ferroresonance in capacitive voltage transformer (CVT), constituting its impact, initiation, and suppression techniques. The core focus in this paper is ferroresonance in CVT due to switching events, on which the documented literature is very scarce. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

中性点接地系统铁磁谐振非线性动力学分析

为了有效地抑制电力系统中铁磁谐振经常发生并严重威胁系统运行安全的复杂现象,应用非线性动力学中相平面、庞加莱截面、Lyapunov指数等方法分析了一典型110kV变电站中由断路器均压电容、系统设备对地电容及电磁式电压互感器铁心电感构成的铁磁谐振电路。通过对不同参数条件下系统中出现的基频谐振、分频谐振及混沌谐振的计算分析,可知应用非线性动力学相关理论及分析方法研究铁磁谐振现象,可确定不同谐振类型及其谐振区域。该法也将为深入理解系统铁磁谐振物理机理,有效防治铁磁谐振提供理论依据。     

断线故障引发铁磁谐振的验算分析

对某变电站不接地系统中1条馈出线因断线故障引起的铁磁谐振进行了分析,并对各种可能的断线故障所引起的分频、基频、高频谐振分别进行了验算。总结了不接地系统的断线谐振的规律,并提出有关预防措施和对策。     

Analysis of Ferroresonance Modes in Power Transformers Using Preisach-Type Hysteretic Magnetizing Inductance

The magnetic hysteresis phenomenon plays an important role in the ferroresonance behavior of a transformer. However, most existing transformer models for the analysis of the ferroresonance phenomenon either ignore the hysteresis effects or represent it based on the hysteresis major loop and scale it for lower current levels. Such a modeling approach does not reflect the actual physical behavior of the magnetic core with respect to the ferroresonance phenomenon. This paper, based on Preisach theory, introduces an accurate model of hysteretic inductor to represent a single-phase transformer for the investigation of the ferroresonance phenomenon. Based on the developed model, time-domain simulation studies show that even in the case of a single-phase transformer where no magnetic coupling exists between the three-phases, all known types of ferroresonance, including fundamental, sub-harmonic, quasi-periodic and chaotic modes, may occur. The effects of hysteresis and its initial conditions, grading capacitors and transformer winding capacitance on occurrence of ferroresonance and its change of mode are also discussed     

基于ARM+DSP结构的PT铁磁谐振智能消谐装置设计

电磁式电压互感器在电网监测系统中是相当重要的设备。由于PT铁磁电感的饱和引发铁磁谐振从而产生长时间的过电压是电力系统中较为常见的一类问题。为了解决该问题,设计了一种新型的基于ARM+DSP结构的智能铁磁谐振抑制装置。利用DSP芯片通过快速傅里叶变换算法对配电网电压数据进行分析,判断铁磁谐振是否产生,并与ARM芯片通信。利用ARM控制阻尼电阻的投切来完成对铁磁谐振的抑制以及对相关谐振信息的显示、存储和上传。该装置充分利用DSP的运算能力和ARM的控制能力从而准确快速检测出铁磁谐振是否发生并对其进行快速抑制和存储。     

铁磁谐振过电压原因分析及预防

对铁磁谐振产生的危害、原因、条件、现象及运行中发生铁磁谐振如何处理进行了阐述：并结合产现场实际发生的一次铁磁谐振现象,分析了具体原因,并制定了切实可行的防范措施。     

Fuzzy理论在电力系统铁磁谐振研究中的应用

根据电力系统铁磁谐振的模糊性 ,应用Fuzzy理论对电力系统发生铁磁谐振的可能性、影响因素及防止措施进行了研究。这种新方法对补充和完善铁磁谐振问题的研究具有重要的意义     

Analyzing the stochastic behavior of ferroresonance initiation regarding initial conditions and system parameters

Power quality and power disturbances are the most important increasing factors throughout electrical networks. Ferroresonance as one of these disturbances can cause quality and security problems. This paper analyzes the stochastic behavior of ferroresonance as a nonlinear resonance phenomenon of the erratic nature and difficult prediction. Furthermore, the impact of different parameters on the initiation of ferroresonance is investigated. It is illustrated that a small change in the initial conditions leads to a large difference in the long-term behavior of the system, and this makes the future of the system unpredictable. Based on the stochastic behavior of ferroresonance some papers took different parameters into account and attempted to identify the basins of attraction for different ferroresonance regions. Here, according to real condition it is illustrated that these basins are highly depending on the initial conditions and there are no transparent boundaries for them. Also, by changing different parameters and initial conditions, the probability degree of ferroresonance initiation is calculated and depicted. Moreover, the impact of source angle on the ferroresonance initiation is investigated.     

TV谐波铁磁谐振检测方法的探讨

铁磁谐振引起系统过电压,常造成继保装置误动。为准确判断铁磁谐振类型,用消谐装置有效消谐,分析了谐波谐振的谐振条件,详细介绍了检测各种谐波成分的两种算法原理,即插值FFT算法和Prony算法,为判别谐振类型提供了有效手段。通过构造多种频率共存的谐振信号,利用算法编程进行数值仿真和谐振信号的频谱分析,以验证算法原理的正确性。结果表明:两种算法估计的信号中各种频率成分的幅值、相位误差较小,能为消谐装置提供有效的铁磁谐振类型检测方法。     

SST在铁磁谐振过电压模态参数辨识中的应用

铁磁谐振过电压幅值大,易对电网造成破坏性冲击,为此将同步挤压小波变换(synchrosqueezing wavelet transform,SST)运用于铁磁谐振过电压模态识别中。首先应用SST和相关系数法提取出铁磁谐振过电压的主模态量;然后对主模态量进行希尔伯特变换计算其瞬时频率、瞬时幅值,实现主模态量的类型、幅值及其激发时刻的准确描述,实现铁磁谐振过电压的有效识别。仿真及实例分析结果表明该方法的可行性、有效性和准确性,为铁磁谐振过电压的有效治理奠定基础。