International Journal of Science, Engineering and TechnologyAuthors- Md Roknuzzaman, Shinichi Hamasaki
Abstract- A transformer-less hexagonal modular multi-level converter (H-MMC) has been introduced for variable frequency regulation in the power generation side. A control algorithm based on the phase-locked loop (PLL) strategy is proposed in this paper to deal with variable frequency on the generation side. Regarding the control to keep balancing the capacitor voltages, the circulating current model is proposed in this paper to control the module current. This research proposes a power flow control strategy considering the current flow between the two sides of the H-MMC. In addition, a modified neutral offset voltage injection method is presented for suppressing the module capacitor voltage by balancing the branch energies.
