Decentralized Control Using Wireless Signal Communication for Multi-Port EV Charger with Multiple Cells

Abstract

This paper proposes a decentralized control scheme of a multi-cell AC/DC converter for electric vehicle (EV) charger applications. The multi-cell topology effectively achieves high scalability by connecting cells in series and parallel. Generally, the multi-cell topology requires a lot of signal lines between the master control and slave controllers in order to control the power-sharing between the cell converters. Thus, the maintainability of the power converters is restricted with these wires. The proposed control scheme with a wireless communication for the EV charger requires no signal wires between master and slave controllers. The features of the proposed decentralized scheme are; 1)it allows communication delay of several hundred milliseconds, 2)each unit, which consists of three single-phase AC/DC converters, has an independent the slave controller. The proposed method is verified by with six units. The power-sharing is demonstrated by the the 7.2-kW prototype. The imbalance rate of the input current is suppressed by 7% or less.