一种用于VSC-HVDC谐波抑制的重复控制策略

摘要

In allusion to the high content of 5-,7-,11-and 13-order harmonics in the AC system of VSC-HVDC,a kind of control method is adopted by using series connection of modified repetitive controller and PI regulator,which has only half of the control period in traditional repetitive controller.Besides,it has smaller steady state errors and can achieve the function of eliminating the system odd harmonics largely.A VSC-HVDC system of two terminals was built in PSCAD/EMTDC,through the simulation and analysis on the harmonic contents of the AC current in the side of converter 1 and 2 without repetitive control added,with traditional repetitive control added and the modified one respectively.The result validates that the modified repetitive control has a better function of suppressing the harmonics.%针对VSC-HVDC交流系统中5、7、11、13次谐波含量较大,采用一种改进型重复控制与PI调节器串联的控制方法.该方法的控制周期仅为传统重复控制周期的一半,具有较小的稳态误差,可以大幅度地消除系统各次奇次谐波.在PSCAD/EMTDC中搭建一个两端的VSC-HVDC系统,对未加重复控制、添加传统重复控制和改进型重复控制三种情况下换流站1、2侧交流电流的谐波含量进行仿真分析,结果表明改进型重复控制具有更好的谐波抑制效果.