A novel DVR based on parallel-connected diode-clamped modular multilevel converters

The dynamic voltage restorer (DVR) is a fast and efficient solution to voltage sag problems. This paper proposes a new configuration of DVR which is based on the parallel diode-clamped modular multilevel converter (parallel-DCM2C). In the parallel-DCM2C topology the capacitor voltages distributed in the sub-modules (SMs) can be balanced automatically without any balancing control algorithms. Additionally no SM capacitor voltage sensors are required. In this paper the compensation strategy is also developed with the new configuration. Experimental results verified the voltage self-balancing performance and compensation functionality of this novel DVR.