Design and implementation of an isolated high-power high-voltage AC/DC converter with modular technology

This paper is on the development of a high-voltage high-power isolated AC-DC converter, which can be used as the charger or DC power supply of an electric vehicle charging station, and is based on modular technology. The proposed architectural structure is similar to the design of high-voltage solid-state transformers, and it can significantly reduce the size and weight of the charging station framework as well as enhance the ability to meet the future smart grid performance requirements. This paper adopts the cascade structure for the proposed input stage, followed by independent high-frequency transformer based DC-DC converters. As the cascade input has the same input current, the voltage and power balance control needs to be considered, particularly in the case of the rear stage output variations. Since the output side is parallel, the appropriate current sharing control must also be considered. Finally, a prototype of the two modules cascaded system is achieved to verify the control idea. Each module is about 400W and consists of a single phase rectifier sourced by AC 110V input and DC 200V output, and a second stage of 200V / 48V with high-frequency transformer. © 2020, National Taiwan University of Science and Technology. All rights reserved.