A novel generalized multilevel converter with the application in D-STATCOM

The multilevel converter is widely used in the industrial field of high-voltage and high-power. However, the active power of the cascaded multilevel converter cannot freely exchange among the three-phase bridge arm. For the problem, this paper proposed a novel generalized multilevel converter topology, which is composed of a cascaded multilevel converter and a three phase converter with a common capacitor of DC side. Based on this topology, the new Distribution Static Synchronous Compensator (D-STATCOM) can distribute the output voltage of the chain unit and the DC side common-capacitor unit. It is helpful for the realization of the active power exchange between the three phase bridge arms, and realizes the control of the unit DC voltage while realizing the three-phase unbalance compensation of the distribution network. The effectiveness and performance of this topology are verified by simulation and has been tested on a practical operation of 3.3kV equipment. It is possible for D-STATCOM to be used in industrial application of three phase unbalanced compensation in medium voltage distribution network.