A control method for inductor current balancing in current source modular multilevel converter

Current source modular multilevel converter (CSMMC) is a potential topology for the high-power applications with low-voltage and high-current requirements. One of the most challenging issues associated with the CSMMC is the submodule inductor currents imbalance if it is not properly controlled. This paper presents a control method for submodule inductor currents balancing in a CSMMC. The control method is implemented using carrier phase shifted sinusoidal pulse width modulation (CPS-SPWM) as a switching technique and is based on a proportional controller. The validity of the proposed control method is confirmed by the simulation of a three phase five level CSMMC using PSCAD/EMTDC. The obtained results exhibit the effectiveness of the proposed inductor current balancing control for the CSMMC under both steady state and dynamic conditions.