Abstract

To integrate large scale distribution consumers and distributed energy resources, new revolutionary features have to be implemented in power distribution networks such as access to low voltage (LV) DC interconnection points, reconfigurable power flow management, smart protection, higher resilience, lower failure rate, fault/disturbance isolation, low power losses, high reliability and high power quality. In this paper, an innovative topology for a Solid State Transformer (SST) based on family of modular converters is proposed. The proposed modular SST addresses all the above features aimed for future hybrid distribution systems. Moreover, to increase power density and avoid the use of several distributed Medium Frequency Transformers (MFTs), such as SSTs based on dual active bridge (DAB) configuration, the proposed topology uses a centralized high power MFT between the modular converters, which reduces the overall footprint of the SST. Simulation results validate the proposed topology performing excellent steady-state and transient operation to regulate output voltages and control bidirectional power flows among its three ports.