交直流混合微电网并联双向互联变换器环流抑制与功率控制

Circulating Current Suppression and Power Control of Paralleled Bidirectional Interlinking Converters in Hybrid AC/DC Microgrid

针对交直流混合微电网中多台双向互联变流器(Bidirectional interlinking converter,BIC)并联运行时功率流动、分配以及环流问题,提出一种用于多并联BIC的分布式电源管理控制策略,其中每个BIC设计有独立的局部分布式控制器,计算出各自的功率参考值,并可根据不同功率额定值按比例分配,实现两子网间功率流动及不同BIC间的功率分配;此外,在零矢量前馈控制策略的基础上,提出一种虚拟BIC概念,以实现多并联BIC环流抑制。仿真与硬件在环试验结果表明该策略可有效控制两子网间的功率流动及多模块间环流抑制。

Aiming at the power flow, distribution and circulation problems when multiple bidirectional interlinking converters(BICs)are operating in parallel in AC-DC hybrid microgrids, a distributed power management control strategy for multi-parallel BICs is proposed. Each BIC is designed with an independent local distributed controller, which calculates its own power reference value, and can be allocated proportionally according to different power ratings to realize the power flow between the two sub-networks and the power distribution between different BICs. In addition, based on the null vector feedforward control strategy, a virtual BIC concept is proposed to realize the multi-parallel BIC circulating current suppression. The simulation and hardware-in-the-loop experimental results show that the strategy can effectively control the power flow between the two sub-networks and suppress the circulating current between multiple modules.