PROJECT TITLE :

A New Parallel ÐConnected Diode ÐClamped Modular Multilevel Converter with Voltage Self-balancing - 2017

ABSTRACT:

The modular multilevel converter (MMC or M2C) is an emerging enticing multilevel topology for medium-voltage high-power applications. The capacitor voltage balancing control and the improvement of output current rating are two difficult issues of MMC. This paper proposed a replacement parallel-connected diode-clamped M2C (DCM2C), in that every arm consists of 2 parallel-connected clusters. During this topology, the capacitor voltages will be balanced automatically while not any balancing control algorithms. Theoretically, no voltage sensors are needed to measure the capacitor voltages theoretically. So, the control of the converter will be simplified greatly. With a simple current-sharing management, an equal current distribution will be achieved between the 2 clusters. Furthermore, an extended parallel-DCM2C is proposed for larger current applications, and also the corresponding current-sharing management method is developed. Experimental results validated the voltage self-balancing capability of parallel-DCM2C and also the effectiveness of the proposed current-sharing control.