Evaluation of GaN Power Transistor Switching Performance on Characteristics of Bidirectional DC-DC Converter

Abstract

The paper deals with the experimental analysis of the switching performance of selected GaN (Galium Nitride) power transistor, whose use is then expected in bidirectional buck/boost DC-DC converter. The switching performance was evaluated through highly accurate and verified simulation models of GS61008P transistor from GaN systems. Experiments have been provided for a wide spectrum of switching frequency and load current in order to verify transistor performance. Then, based on the results, it was expected that high-frequency operation (above 500 kHz) should not distort the efficiency performance of the designed bidirectional converter. This was confirmed after laboratory measurements of the efficiency of the proposed DC-DC converter, while operation under very high switching frequency was more effective compared to low-frequency operation. Over 95 % of efficiency was achieved for both buck and boost mode (125 W), even switching frequency was above 500 kHz.