改进的级联STATCOM直流侧均压控制策略

针对级联静止同步补偿器(STATCOM)直流侧各H桥模块因损耗差异易产生电压不平衡的问题,在分层控制及能量交换思想的基础上,提出一种改进的相间及相内均压控制策略。在全局稳压控制所得的调制波基础上,通过在相间、相内均压控制时分别叠加一个与有功电流方向平行的误差分量,使触发角微小相移,从而使能量在各相、各H桥模块之间合理分配,达到均衡相间及同相各H桥模块直流侧电压的目的。仿真结果表明,所提方法可以有效均衡STATCOM直流侧相间、相内电压。

An Improved STATCOM DC Side Voltage Control Strategy

In view of the flaw of voltage imbalance due to differences in loss exhibited by H bridge module on the DC side of the cascade static synchronous compensator (STATCOM), and based on the notion of hierarchical control and energy exchange, an improved interphase voltage equalization control strategy has thus been proposed. Based on the modulation wave obtained from the global voltage regulation control, an error component parallel to the direction of the active current has been superimposed, thus shifting the tiny angle of the trigger angle, which enables a reasonable allocation of the energy between each phase and each H bridge module, and thus achieving the purpose of balancing the DC side voltage of H bridge modules. The simulation results show that the control strategy can effectively balance the inter-phase and phase voltage on the DC side of STATCOM.