Bidirectional electric vehicle chargers connected to low-voltage grids: modeling, experimental assessment and study of supraharmonic distortions

• Grant number: 24/13330-3
• Support Opportunities: Regular Research Grants
• Start date: December 01, 2024
• End date: November 30, 2027
• Field of knowledge: Engineering - Electrical Engineering - Industrial Electronics, Electronic Systems and Controls
• Principal Investigator: Augusto Matheus dos Santos Alonso
• Grantee: Augusto Matheus dos Santos Alonso
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated researchers: Amilcar Flamarion Querubini Gonçalves ; Elisabetta Tedeschi ; Fernando Pinhabel Marafão ; Ricardo Quadros Machado ; Vilma Alves de Oliveira
• Associated scholarship(s): 25/06764-0 - Study and Computational Implementation of a T-type NPC Converter, BP.IC; 24/23012-9 - Modeling and Control of a T-NPC Inverter Applied to Bidirectional Electric Vehicle Chargers, BP.MS

Abstract

In recent decades, a strong transition towards the commercialization of electric vehicles (EVs) have been evidenced, being mainly motivated by sustainability aspects, resulting in significant changes to the electric power distribution and transportation sectors. Although plug-in EVs present the attractive feature of substituting fossil fuel by electricity, their dense penetration into low-voltage power grids leads to an increased energy demand burden, and power quality is also deteriorated by the interconnection of their switching power electronic converters (PECs). Currently, the bidirectional power flow capability proposed for some EV charger topologies have provided an interesting alternative to reduce their impact in power demand, allowing them to also dispatch energy to the grid. However, the technical literature does not present a clear discussion about the multi-stage modeling of such EV chargers, neither discusses the integrated design of the bidirectional power controllers employed within their PECs. Moreover, advanced studies on low voltage grids have recently pointed out an emerging power quality problem caused by such EVs, referring to the existence of supraharmonic distortions (i.e., those between 2 kHz - 150 kHz), which causes unwanted interactions between PECs and the deterioration of voltage quality. This project proposes a systemic modeling of the PECs adopted in a bidirectional EV charger, considering and implementation based on the integration of the Vienna/Type-T NPC and Dual Active Bridge topologies. In addition, this project also proposes the investigation of the controllers employed on such an EV chargers. Another additional research proposal of this project refers to the investigation of high frequency distortions caused by EV chargers, assessing the root causes and power quality consequences in a low voltage network. Theoretical and computational studies are expected for the development of the project, aiming to develop and validate the derived models for the targeted EV charger, also verifying the viability of the controllers designed for the PECs. Studies related to supraharmonic emissions/interactions will also be carried out based on computational and real-time simulations. Finally, an experimental prototype of the proposed EV charger will also be developed, on a laboratory scale, for validation purposes and practical studies. (AU)