一种新型并联三电平注入式电流型变换器拓扑

A New Topology of Three-Level Reinjection Current Source Converter in Parallel

提出了一种三相并联型自换相三电平注入式电流型交直流变换器拓扑结构,给出了开关控制方案和进行了工作原理分析,该拓扑结构的电路完全满足多电平谐波注入原理的要求。基于PSCAD/EMTDC软件环境进行了仿真,验证了文中提出拓扑和控制方案的可行性。新型三电平注入式电流型变换器结构方便拓展到多电平,与现有的并联多电平电流型变换器拓扑结构相比,处于开通状态的注入电路开关平均分配直流输出电流,降低了对注入支路开关器件的电流容量的要求和开关通断时的电流变化率,为主桥开关提供了可靠的零电流开关条件,省去了设计制造大容量多抽头电抗器的不便。

A new topology of three-level reinjection current source converter in parallel is proposed. The control method and the operational principle are given. The circuit scheme with the proposed topology satisfies all requirements of multi-level harmonic reinjection principle. The EMTDC/PSCAD program is used here for the verification of the theoretical results derived earlier with the three-level configuration. The new three-level topology is easily extended to multi-level topology. Compared with the existing topology of multi-level reinjection current source converter in parallel, the reinjection switches being on-state average the dc output current, and therefore the rated current of the reinjection switches and the current change ratio during the switches transition are depressed. Also the steady zero current condition is provided to the main bridge switches by the reinjection switches, and the high capacity multi-taooed reactor can be eliminated.