Design and Control of a Compact 7.2 kW GaN-Based Bidirectional Isolated On-Board Charger (OBC)

This thesis presents significant advancements in bidirectional onboard chargers (OBCs) for electric vehicles, addressing critical challenges in power factor correction, efficiency, and power density. The research introduces innovative control strategies and hardware designs by incorporating high power GaN switches that substantially improve OBC performance and compactness. The thesis introduces three major contributions: First, a novel Zero Crossing Voltage Control (ZCVC) strategy for Power Factor Correction (PFC) applications is developed. This approach ensures a consistent sinusoidal AC current, eliminates second harmonic distortions without notch filters, and achieves stability within 1.5 grid cycles during operational changes. The ZCVC method demonstrates a near-unity power factor, minimal Total Harmonic Distortion (THD), and reduced computational burden. Second, an innovative Zero Voltage quasi-Zero Current Switching (ZVqZCS) scheme is proposed for non-resonant isolated Dual Active Bridge (DAB) converters. This method achieves full Zero Voltage Switching and 75% quasi-Zero Current Switching across a wide range of input and output voltages while minimizing inverse power flow and significantly reducing di/dt in power loops. The proposed buck-boost ZVqZCS scheme is implemented in both charging and discharging modes, as well as constant-current (CC), constant-power (CP), and constant-voltage (CV) operations. Burst mode is introduced to further increase the range of full ZVS and 75% qZCS. Finally, the research presents remarkable hardware design improvements, achieving ultra-high power densities of 14kW/L for Totem-Pole PFC, 37 kW/L for DAB, and 10 kW/L for the overall OBC, representing 2X, 5X, and 3X improvements over latest reference designs from Texas Instruments, ST Microelectronics, and WolfSpeed, respectively. Peak efficiencies of 99% for interleaved PFC, 98.8% for DC-DC isolated DAB stage, and 97.8% for the overall OBC are demonstrated. These advancements significantly contribute to the development of more efficient, compact, and reliable OBCs using GaN technology supporting the ongoing transition to sustainable transportation.

Name thesis:degree_name

Doctor of Philosophy (Ph.D.)

Level thesis:degree_level

Doctoral

Discipline thesis:degree_discipline

Engineering, Electrical and Computer

Grantor dc:publisher

Carleton University

Year dc:date.issued

2025

Author dc:creator

• Jalalabadi, Esmaeil

Statement dc:rights

• Copyright © 2025 the author(s). Theses may be used for non-commercial research, educational, or related academic purposes only. Such uses include personal study, distribution to students, research and scholarship. Theses may only be shared by linking to the Carleton University Institutional Repository and no part may be copied without proper attribution to the author; no part may be used for commercial purposes directly or indirectly via a for-profit platform; no adaptation or derivative works are permitted without consent from the copyright owner.

Language dc:language.iso

en

DOI

10.22215/etd/2025-16575

OAI identifier oai:identifier

oai:carleton.scholaris.ca:20.500.14718/43942