Feasibility of Quasi-Square-Wave Zero-Voltage-Switching Bi-Directional DC/DC Converters with GaN HEMTs

Furkan Karakaya,Ozan Keysan,Özgür Gülsuna

doi:10.3390/en14102867

Furkan Karakaya, Ozan Keysan + Show 1 more

Open Access

https://doi.org/10.3390/en14102867

Copy DOI

Journal: Energies	Publication Date: May 16, 2021
Citations: 4	License type: CC BY 4.0

Affiliation: Middle East Technical University

Abstract

There are trade-offs for each power converter design which are mainly dictated by the switching component and passive component ratings. Recent power electronic devices such as Gallium Nitride (GaN) transistors can improve the application range of power converter topologies with lower conduction and switching losses. These new capabilities brought by the GaN High Electron Mobility Transistors (HEMTs) inevitably changes the feasible operation ranges of power converters. This paper investigates the feasibility of Buck and Boost based bi-directional DC/DC converter which utilizes Quasi-Square-Wave (QSW) Zero Voltage Switching (ZVS) on GaN HEMTs. The proposed converter applies a high-switching frequency at high output power to maximize the power density at the cost of high current ripple with high frequency of operation which requires a design strategy for the passive components. An inductor design methodology is performed to operate at 28 APP with a switching frequency of 450 kHz. In order to minimize the high ripple current stress on the output capacitors an interleaving is performed. Finally, the proposed bi-directional converter is operated at 5.4 kW with 5.24 kW/L or 85.9 W/in3 volumetric power density with air-forced cooling. The converter performance is verified for buck and boost modes and full load efficiencies are recorded as 97.7% and 98.7%, respectively.

Highlights

Each power converter application has its own needs and requires picking a feasible and reliable topology for a well-suited design
Jafari et al propose a Dual Active Bridge (DAB) topology with a very high power density for photovoltaic applications in [2]. 97.4% peak efficiency is achieved with GaN High Electron Mobility Transistors (HEMTs) where the switching frequency is 300 kHz
All waveforms are recorded by a digital oscilloscope, Waverunner 44xi (Teledyne LeCroy, New York, USA) and the current waveforms are measured by a current probe, TCP305A (Tektronix, Bracknell, UK)

Summary

Introduction

Each power converter application has its own needs and requires picking a feasible and reliable topology for a well-suited design. Different power electronics topologies with isolation or not can address those needs in terms of volume, cost, efficiency, gain, device utilization, power and easiness of implementation. Wide band-gap (WBG) devices like Silicon–Carbide (SiC) and Gallium–Nitride (GaN) switches can boost the performance of converters while shrinking their sizes significantly. The Dual Active Bridge (DAB) converters are widely used for different applications. 97.4% peak efficiency is achieved with GaN High Electron Mobility Transistors (HEMTs) where the switching frequency is 300 kHz. More interestingly, the proposed converter utilizes a tapped transformer where the voltage regulation span enlarges without losing the soft-switching [3]. SiC MOSFETs are preferred to increase the switching frequency in [4]

Methods

Results

Discussion

Conclusion