单调谐滤波器的滤波特性与短路比的关系  

Relation between short-circuit-ratio and single-tuned filter performance

作　　者：同向前[1] 申明[1] 李牧[1] 

机构地区：[1]西安理工大学自动化与信息工程学院,陕西西安710048

出　　处：《电力自动化设备》2009年第9期62-64,69,共4页Electric Power Automation Equipment

摘　　要：单调谐滤波器在失谐或配置不当的情况下会发生并联谐振并引起电网谐波放大,该现象是由滤波器参数和电网参数共同决定的。引入了滤波器短路比这一新的特征参数,综合表征了滤波系统中的滤波器参数与电网参数。采用滤波器投入前后注入电网的谐波电流之比作为滤波效果的评价指标,通过分析电网不发生谐波放大的充要条件,揭示了电网谐波放大特性与滤波器短路比之间的简明的内在关系。在滤波器对所调谐谐波不发生放大的前提下,单调谐滤波器的最大允许失谐度与短路比成反比。为防止滤波器对调谐频率以下的各次谐波发生并联谐振,滤波器短路比必须避开某些禁值。给出了单调谐滤波器在19次以下谐波的短路比禁值以及合理取值范围。Single- tuned power filter with improper parameters or under detuning may cause serious harmonic current amplification due to the parallel resonance,which depends mostly on the parameters of both filter and distribution system. FSCR（Fiher＇s Short-Circuit-Ratio）,a new characteristic parameter,is introduced to synthetically denote whole filtering system,including fiher and distribution system. The ratio of system harmonic currents with and without filter operation is taken as an index of filter performance assessment. The relationship between harmonic amplification and FSCR is revealed by investigating the sufficient and necessary conditions of harmonic current amplification restraint. On the premise that there is no current amplification of tuned harmonic,the maximum allowable detuning of a single- tuned filter is inversely proportional to FSCR. The FSCR must be apart from some inhibitive values in order to avoid the parallel resonance at the tuned- frequency and below. The inhibitive and rational SCR values of single -tuned filter for 19th harmonic and below are given.

关 键 词：单调谐滤波器 滤波特性 失谐 谐波电流放大 短路比 

分 类 号：TM711[电气工程—电力系统及自动化] TM477