Beyond-Nominal Operation of GaN-Based Converters for High-Power Density Applications

There is zero-tolerance for failure in various critical applications, including aerospace, naval ships, and electric vehicles where power converters are crucial for system operation. Uncertain scenarios, such as sudden converter unit failures may push these systems to operate beyond-nominal conditions and stress other converters on the power system. The loss of even a single converter can risk critical operation capabilities. A 1-MHz buck converter is assumed to be a fully functional component in a damaged power system, and its reliability under a high-stress, beyond-nominal operating condition is investigated to enable full power system capabilities with reduced components. The converter was designed for a maximum current rating of 6.5 A and nominal operation of 5.5 A and tested up to 30% above the nominal current rating. Operating a converter beyond-nominal test conditions places each component at risk of degradation or failure which needs to be monitored in these conditions. For example, the change in on-resistance is an important factor to consider for beyond-nominal operating conditions in switching devices for monitoring health. Therefore, a simple and accurate method to measure the dynamic on-resistance is also provided with experimental results.