Using GaN Switching Devices for Common Mode EMI Reduction in Power Converters

• Main Authors: Jhe-yu Lin, 林哲宇
• Other Authors: 陳德玉
• Format: Others
• Language: en_US
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/wnxkgy

博士 === 國立臺灣大學 === 電機工程學研究所 === 105 === The gallium nitride (GaN) cascode switch has received much attention recently for line-operated medium-high frequency (200 kHz to 500 kHz) applications. Because of its device structure, there are two package options available with regard to the tab internal connection; either the drain terminal or the source terminal is electrically connected to the metallic plate of the device package, unlike the conventional vertical power Si based MOSFET in which the drain terminal can be connected to the device metallic plate. It is proposed in the dissertation that taking advantage of the unique feature of GaN devices packages mentioned above and using a proper combination of the GaN devices in a converter circuit converter common mode noise can be reduced. As a result, the converter conducted EMI can be reduced. The theory is explained and the rule for proper package selection are described in the dissertertation. A 240-Watt LLC power converter with a front-end power-factor-correction (PFC) circuit was built for experimental verification. In the experiment, significant reduction in the conducted EMI was observed. The proposed strategy can be applied to other converter or inverter configurations. GaN devices provide an option, unavailable in power MOSFET devices to significantly reduce the converter conducted EMI.