Loss Characterization and Analysis of High Voltage E-mode GaN HEMT in Soft-switching Application

Application of wide band gap (WBG) devices are getting a sharp rise in the recent power electronics sector, due to their superior performance when compared to silicon. Even though GaN devices provide a promising efficiency and power density numbers, but high frequency operation limits these benefits. This leaves behind a space for the realization of high frequency based soft switching topologies, which in combination with the GaN makes the converter size smaller and simultaneously efficient. In this unique combination, an accurate design and analysis to estimate the overall losses of the converter is necessary. Typical converter design process starts with the detailed loss estimation analysis, wherein the semiconductor based losses shares the major portion. Traditional analytical way of estimating the soft-switching semiconductor loss is not precise as it mainly depends on the instantaneous circuit conditions. In case of the soft-switching topology, the instantaneous switch voltage and current needs to be monitored to determine the switching loss accurately. This will result in a more realistic semiconductor loss evaluation, which will further ease in improving converter design and analysis. Hence, in this paper the soft-switching condition loss characterization and analysis involving an enhanced-mode (E-mode) GaN implemented in a conventional topology is investigated and verified.