基于重复控制的三相并网控制系统前馈方法

摘要

The disturbance of the grid causes the harmonic current when grid-connected power recovery system is working. The feedforward method is usually used to counteract the influence of utility grid.A three-phase gridconnected power recovery system is designed,the theory of how the utility grid cause the harmonic current is analyzed. By analysing the existing grid current control scheme,a new feedforward method combined repetitive control is proposed to restain the periodic influence and the sudden change of the grid, the accuracy of the grid current is improved.The control strategy is proved to be simple and effective by experiment results,the system is of better dynamic response and lower harmonic current.%蓄电池的能量回收系统在向电网馈电的过程中,电网的波动将会使其输出电流畸变,特别是系统工作于轻载时,通常采用电网电压的前馈控制来抵消电网的影响.在此设计了一套能量回收三相并网系统,在现有并网电流控制方法的基础上,提出将重复控制引入到电网电压前馈计算,以抑制电网周期性的扰动和电网突变对系统前馈的影响,提高并网电流的跟踪精度.实验结果表明,该控制方法易于实现,系统工作时动态响应好,并网电流谐波含量低.