基于阻尼谐振型LCL滤波电路的无变压器型混合电力滤波器的设计与稳定性的研究  

Design and Stability of Transformerless Hybrid Power Filter Based on Damped Resonant LCL Filter Circuit

作　　者：陈岗 张武娟 李俊 王锋 CHEN Gang;ZHANG Wu-juan;LI Jun;WANG Feng(Willfar Information Technology Co.,Ltd.,Changsha 410205,China)

机构地区：[1]威胜信息技术股份有限公司,长沙410205

出　　处：《电力学报》2021年第3期200-218,共19页Journal of Electric Power

基　　金：工信部国家重点研发计划:数字电网关键技术(2020YFB0906000)。

摘　　要：混合滤波器具有谐波滤除率高、补偿容量大、成本低、无谐振风险等优势,是一种性价比高的中高压无功补偿与谐波滤除的方法,可应用于高压、谐波电流含量高、无功负荷大的应用环境中。当高压混合有源滤波器中有耦合变压器时,会造成系统滤波特性降低;去掉耦合变压器,又会带来系统中的高、低压模块间电压匹配不均衡、有源输出开关谐波电压没有被隔离等影响系统稳定性的问题。为此,提出了一种带阻尼谐振型LCL滤波电路的无变压器型混合滤波器的拓扑结构,并基于此结构阐述了提高系统滤波特性与稳定性的关键因素,建立了详细的电路模型,提出了提高系统滤波特性与稳定性的方法,给出了系统关键参数的设计方法。系统主要结构为上下两个LC滤波器串联,中间并联LCL输出滤波器,再串联有源电力滤波器和并联无源电力滤波器。主要作用是通过串联LC滤波器分压,输出滤波器滤除高次开关谐波,有源电力滤波器滤除高次谐波,无源电力滤波器滤除低次大电流谐波。该结构能去除耦合变压器,且能保证抑制高次开关谐波的输出。在这种结构中,系统阻抗和K1值的变化与滤波效果呈正比,系统阻抗和K1值的变化都会影响V_(1h)/U_(Th)在基波处的比值变化,系统阻抗和K_(1)值的变化呈反比,系统的稳定性则与无源和有源连接点V_(1h)的电压有直接关系。因此,当系统阻抗不能改变的情况下,适当增加K1的取值有助于提高系统的滤波特性,同时,输出滤波器对高次开关谐波的滤除效果得到了很好的体现,且不受系统阻抗及K1变化的影响,无源串联基波谐振支路的谐振点尽量与基波保证一致。通过MATLAB幅频特性仿真证明了系统设计与方法的合理性与可行性。同时,进行了样机验证实验:谐波补偿试验表明,装置滤除效果良好,可以很好地跟踪负载,实时性能良好;谐波+无功补偿�Hybrid filter has the advantages of high harmonic filtering rate,large compensation capacity,low cost and no resonance risk.It is a cost-effective means of reactive power compensation and harmonic filtering in me-dium and high voltage,which is applied to high voltage,high harmonic current content and large powerless load.When there is a coupling transformer in the high voltage hybrid active filter,the filtering characteristics of the sys-tem will be reduced.Removing the coupling transformer will also bring problems such as unbalanced voltage matching between high and low voltage modules in the system high and low voltage modules in the system,and the harmonic voltage of the active output switch is not isolated.Therefore,this paper presents a topology struc-ture of transformerless hybrid filter with damping resonant LCL filter circuit.Based on this structure,the key fac-tors to improve the filtering characteristics and stability of the system are expounded,the detailed circuit model is established,the method to improve the filtering characteristics and stability of the system is proposed,and the de-sign method of the key parameters of the system is given.The main structure of the system is that the upper and lower LC filters are connected in series,the LCL out-put filter is paralleled in the middle,and then the active power filter and the parallel passive power filter are con-nected in series.Its main function is to filter out high-order switching harmonics through series LC filter voltage divider,output filter,active power filter and passive power filter,respectively.This structure can remove the cou-pling transformer and ensure the suppression of the output of high-order switching harmonics.In this structure,the change of system impedance and K1 value is proportional to the filtering effect,and the change of system im-pedance and K_(1)value will affect the ratio change at the V(1h)/U(Th)fundamental wave.The change of system imped-ance and K1 value is inversely proportional,and the stability of the system is dire

关 键 词：混合有源滤波器 耦合变压器 阻尼谐振 滤波特性 电压匹配 开关谐波 电压隔离 系统稳定性 

分 类 号：TN713[电子电信—电路与系统]