New Module with Isolated Half Bridge or Isolated Full Bridge for Modular Medium voltage converter

Abstract

This paper proposes a standard module of "Isolated Half Bridge (IHB)" or "Isolated Full Bridge (IFB)" and its application in MVDC/MVAC system by using modular structure. The fundamental and 2nd harmonic current ripple can be eliminated through connecting the DC links of three phase on the same level. Energy density and system efficiency can be largely improved since the capacitor size is reduced. In addition, energy storage devices can be integrated in the proposed topology and thus make it feasible for smart grid and marine applications. Detailed simulation results of comparison between proposed topology and traditional MMC have been presented. Moreover, medium voltage drive starting from zero frequency is also simulated. Modular DC/DC converters with energy storage are discussed as well.