应用于配电网三端柔性互联的三角形交交变换器

针对配电网三端柔性互联,提出了一种三端口三角形交交变换器.首先,介绍了三端口三角形交交变换器的电路拓扑,其与三端口背靠背模块化多电平换流器相比桥臂数量减少了一半.然后,分析了三端口三角形交交变换器的工作原理,建立其数学模型,并采用相量图法研究其运行特性.之后,结合柔性多状态开关的应用需求设计了控制策略,利用第3个桥臂的电流调节特性,在满足输出馈线功率需求的基础上,实现了2条输入馈线上的功率灵活分配.最后,采用仿真验证了所提出的三端口三角形交交变换器拓扑和数学模型的正确性及其控制策略的有效性.

Delta AC/AC Converter for Three-port Flexible Interconnection of Distribution Network

A three-port delta AC/AC converter is proposed for the three-port flexible interconnection of distribution networks. Firstly, the topology of the three-port delta AC/AC converter is described. Compared with the three-port back-to-back modular multilevel converter (MMC), the number of bridge arms in the proposed topology is reduced by half. Secondly, the working principle of the three-port delta AC/AC converter is analyzed, and its mathematical model is established, while its operation characteristics are studied by phasor diagram method. Thirdly, the control strategy is designed according to the application requirements of flexible multi-state switch (FMSS). According to the current regulation characteristics of the third bridge arm, the flexible power distribution between the two input feeders is realized based on the power demand of the output feeder. Finally, the validity of the proposed topology of the three-port delta AC/AC converter and the mathematical model, as well as the effectiveness of the control strategy, are verified by the simulation.