A 4.16kV/750kVA MV Power Conditioning System for Distribution System Applications

Distribution system applications encompassing a wide range of technologies from established ones like grid-connected battery energy storage systems (G-BESSs) to emerging solutions like ultra-fast charging stations are growing. These applications normally rely on bulky and heavy line-frequency transformers (LFTs). However, medium-voltage power conditioning systems (MV-PCSs) do not require LFTs, have potentially higher system efficiency and improved volumetric and gravimetric densities. A SiC-based 4.16 kV, 750 kVA MV-PCS is investigated to assess its feasibility in supporting an 800-V G-BESS. The MV-PCS two stages are an MV active front-end converter (MV-AFEC) and an MV isolated bidirectional dc-dc converter (MV-IBDC). The AFEC is based on 3.3 kV SiC MOSFET power modules, and the IBDC on 1.2 kV and 3.3 kV SiC MOSFET modules. The primary objective is to evaluate the developed MV-PCS in terms of the selected figures of merit, including system losses, volumetric power density, and gravimetric power density aided by PLECS software. A MV building block prototyped using custom 3.3 kV, 200 A SiC MOSFET modules was characterized by performing static, dynamic, and thermal analyses as well as extracting the module main parameters.