基于APF的地铁供配电系统谐波补偿研究

Research on Harmonic Suppression for Improved APF in Metro Power Supply System

随着各种非线性用电设备的广泛使用,造成地铁供配电系统谐波含量不断增加。针对目前大部分地铁车站采用LC无源滤波装置这一谐波治理措施存在的只能消除特定的几次谐波、易产生谐波等缺陷这一问题,提出在地铁降压变电所0.4kV侧装设有源电力滤波器(active power filter,APF)方案,以对供配电系统的谐波进行补偿。阐述了APF的工作原理;引入均流调节器与基于瞬时无功功率理论的i_p-i_q谐波检测法中的低通滤波器级联提出一种基于级联低通滤波器的电流谐波检测改进型方法;引入模糊自适应PI控制器加以电流反馈形成电压闭环控制从而更好地稳定直流侧电容电压以提高谐波补偿效果;最后在MATLAB/Simulink平台构建仿真模型。仿真结果表明所提出的基于APF的地铁供配电系统谐波补偿系统在实现良好地稳定直流侧电容电压的情况下同时能够提高电流谐波的检测精度,具有更优的谐波补偿性能。

The harmonic content of metro power supply and distribution system increases along with the nonlinear electrical equipment were used widely. Currently most subway stations adopt the control measures of LC passive filter to suppressSthe harmonic,which the measures only can suppress specific harmonics and are easy to produce defects of harmonic wave. In order to solve this problem, active power filter （APF） is proposed to be installed in the 0.4kV side of the step-down substation to suppress the harmonic. The working principle of APF is expounded. By bringing in the average current regulator to cascade with low pass filter, an improved current harmonic detection method with a cascaded LPF based on the ip-iq algorithm of the instantaneous reactive power theory is proposed. To stable the DC side capacitor voltage well so as to improve the effect of harmonic compensation, this paper brings in the fuzzy adaptive PI controller and the current feedback to form a closed voltage loop control. Finally the simulation is built in the MATLAB/Simulink platform, and the simulation results show the harmonic compensation system for metro power supply and distribution system based on APF not only can stable the voltage of the DC capacitor well but also improve the accuracy of current harmonic detection, and its harmonic suppression performance is better.