地铁车辆空调系统变频改造及谐波抑制方案技术研究

Technical study on variable frequency transformation and harmonic suppression of metro air conditioning system

随着城市轨道交通行业的飞速发展和国家对“节能减排”的重视,地铁列车空调系统的节能性变得尤为重要。早期地铁空调系统基本为定频空调,在不改变原有定频空调主体结构的前提下,通过换型为变频压缩机、增加变频器,以及开展相关的电路及结构改造可升级为变频空调,从而降低能源消耗。文章以某地铁公司变频空调改造项目为例,分析地铁车辆空调变频改造技术,针对变频改造中线性负载变为非线性负载时谐波电流注入导致谐波电压畸变超标,衍生出的SIV与空调匹配性问题,设计谐波抑制方案,通过在空调输入侧增加电感降低谐波分量,并叠加LC谐振回路对含量相对较高的5次方和7次方谐波进行反向振荡削减其谐波含量,有效将谐波电压降低在设计标准5%范围内。

With the rapid development of urban rail transit industry and the national emphasis on“energy saving and emission reduction”,the energy saving performance of metro air conditioning system has become particularly essential.In the early period,the metro air conditioning system was fixed frequency basically.Under the premise of not changing the main structure of the original system,it can be upgraded to variable frequency air conditioning system by replacing with the variable frequency compressor,adding the frequency converter and carrying out relevant circuit and structural modifications,thereby reducing energy consumption.This paper takes the example of a metro company variable frequency air conditioning system transformation project,analyzes the variable frequency transformation technology of metro air conditioning system.Aiming at the matching problem between SIV and air conditioning system caused by excessive harmonic voltage distortion due to harmonic current injection during linear load transform from non-linear load,we designed a harmonic suppression scheme includes adding inductors on the input side of the air conditioning system to reduce harmonic component,and executing reverse oscillation though superimposing LC resonant circuit to reduce the relatively high content of 5th and 7th harmonics’harmonic content,thus the harmonic voltage is effectively reduced to within 5%of the design standard.