Solid state transformer based on the flying capacitor multilevel converter for intelligent power management

Abstract

Future grids will consist of large scale of integration of both renewable and other distributed energy sources. Therefore, advanced power electronics converters for critical loads will be needed in order to enhance power quality, and to ensure proper and secure operation of future grids. These power converters must be able to provide intelligent power management as well as ancillary services. This paper proposes a solid state transformer (SST) which consists of medium frequency transformer and three-level flying capacitor (FC) topology for intelligent power management. It is tested under various grid events such as voltage excursions, phase jumps and frequency variations. Moreover, it is tested against load disturbances such as load transients and non-linear loads. The SST enhances power quality compatibility and provides good isolation of perturbances between the grid and the loads. The SST is also able to deliver ride through capabilities, which can isolate short term disturbances from the grid to the loads and vice-versa. The Power quality enhancement features are validated under various source and load conditions using computer simulation.