[paper] GaN-HEMT Compact Model

Ke Li¹, Paul Leonard Evans², Christopher Mark Johnson², Arnaud Videt³, and Nadir Idir³

A GaN-HEMT Compact Model Including Dynamic RDSon Effect

for Power Electronics Converters

MDPI Energies 2021, 14, 2092.

DOI: 10.3390/en14082092

1 Centre for Advanced Low-Carbon Propulsion Systems, Coventry University, Coventry CV1 2TL, UK
2 Power Electronics, Machines and Control Group, University of Nottingham, Nottingham NG7 2RD, UK;
3 Laboratoire d’Electrotechnique et d’Electronique de Puissance, Université de Lille, France;

Abstract: In order to model GaN-HEMT switching transients and determine power losses, a compact model including dynamic RDSon effect is proposed herein. The model includes mathematical equations to represent device static and capacitance-voltage characteristics, and a behavioural voltage source, which includes multiple RC units to represent different time constants for trapping and detrapping effect from 100 ns to 100 s range. All the required parameters in the model can be obtained by fitting method using a datasheet or experimental characterisation results. The model is then implemented into our developed virtual prototyping software, where the device compact model is co-simulated with a parasitic inductance physical model to obtain the switching waveform. As model order reduction is applied in our software to resolve physical model, the device switching current and voltage waveform can be obtained in the range of minutes. By comparison with experimental measurements, the model is validated to accurately represent device switching transients as well as their spectrum in frequency domain until 100 MHz. In terms of dynamic RDSon value, the mismatch between the model and experimental results is within 10% under different power converter operation conditions in terms of switching frequencies and duty cycles, so designers can use this model to accurately obtain GaN-HEMT power losses due to trapping and detrapping effects for power electronics converters.

Fig: GaN-HEMT device structure and its compact model

Acknowledgments: The authors would like to acknowledge Loris Pace for technical discussions and experimental support. This research was funded by the UK Engineering and Physical Sciences Research Council (EPSRC) through research grant [EP/K035304/1 and EP/R004390/1] and French State Region Plan Contract Intelligent Integrated Energy Converter (CPER-CE2I) project.