中文摘要：

H桥级联静止同步补偿器（STATCOM）直流侧电容电压的波动,会引起系统直流侧母线电压不平衡,从而影响系统的可靠运行。针对该问题,在直流侧电容电压三级平衡控制策略的基础上,采用比例谐振（PR）控制器对全局平均直流电压进行控制,以提高控制效果;采用自抗扰控制器（ADRC）对相间直流电压进行平衡控制,实现对外界扰动的动态补偿;采用上下平移每个功率单元调制波的方法,实现相内直流电压平衡控制,并配合载波相移调制策略（CPS-PWM）,易于FPGA数字实现。实验结果表明,提出的控制方法是有效的,且具有良好的动态性能和较强的鲁棒性。

英文摘要：

The DC capacitor voltage fluctuation of H-bridge cascaded STATCOM will induce the DC voltage imbalance and influence the reliable system operation,aiming at which,the PR（Proportional Resonant） controller based on the three-level balance control strategy of DC capacitor voltage is adopted to improve the average global DC voltage control;the ADRC（Active Disturbance Rejection Controller） is applied to realize the inter- phase DC voltage balance control and the dynamic compensation for outside disturbance;the modulation wave of each power unit is translated to realize the in-phase DC voltage balance control and,combined with the CPS-PWM（Carrier Phase Shifting PWM）,to facilitate the FPGA digital realization. Experimental results show that,being effective,the proposed control method has good dynamic performance and strong robustness.