1 Department of Energy Technology, The Faculty of Engineering and Science, Aalborg University, VBN2 Electric Power Systems, The Faculty of Engineering and Science, Aalborg University, VBN3 The Faculty of Engineering and Science, Aalborg University, VBN
The modular multilevel converter (MMC) is attractive for medium- or high-power applications because of the advantages of its high modularity, availability, and high power quality. The voltage balancing of the floating capacitors in the cascaded submodules of the MMC is a key issue. In this paper, a voltage-balancing control method is proposed. This method uses the phase-shifted carrier-based pulsewidth modulation scheme to control high-frequency current components for capacitor voltage balancing in the MMC without measuring the arm currents. Simulations and experimental studies of the MMC were conducted, and the results confirm the effectiveness of the proposed capacitor voltage-balancing control method.
I E E E Transactions on Power Electronics, 2014, Vol 29, Issue 1, p. 66-76
Capacitor voltage balancing; Control method; Modular multilevel converter