Peak Arm Current Minimization of Modular Multilevel Converter Using Multiple Circulating Current Injection

Conventional circulating current (CC) control schemes of the modular multilevel converters (MMC) typically suppress CC to zero reduce system loss. However, non-zero can also bring additional benefits. In this paper, a peak arm minimization method MMC using multiple injection (MCCIC) is studied. Specifically, second-order (SOCC) and fourth-order (FOCC) are used achieve purpose. Firstly, amplitude phase angle SOCC determined shape into saddle wave. Next, FOCC studied further cut flat crest wave minimize current. The feasibility boundary for proposed strategy discussed quantitatively. Moreover, decoupling developed precise FOCC. end, techniques verified via both PSCAD/EMTDC simulation RTLAB&RTU-BOX hardware-in-the-loop experiment. results show that operating with high power factors be reduced by about 23% its handling capacity increased 30%.