On Dynamic Characterization Evaluation and Control of Active Gate Drivers for SiC power MOSFETs

Abstract

Silicon Carbide (SiC) powerMetal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs) bear the potential of revolutionizing power electronic converters in regard to high efficiency, but also high power density converters and converter in harsh environmental conditions. These devices switch at unprecedented speed that can easily cause interference and risk to the surrounding circuitry. Power MOSFETs require gate driver circuits to be switched on or off. Conventionally, Two Level Voltage Source Gate Drivers (VSGDs) have been used to realize this functionality. However, both the static and dynamic behavior of SiC powerMOSFETs strongly depends on the operating conditions, such as DC voltage and load current. Two Level VSGDs cannot account for these changes, which results in suboptimal utilization of the powerMOSFETs in a wide range of operating conditions. Active Gate Drivers (AGDs), as opposed to conventional Two Level VSGDs, can be adjusted during the run time of the converter and therefore adapt the powerMOSFET behavior to changing operating conditions. AGDs will therefore be of major importance to optimally utilize the advantages of SiC power MOSFETs in future power converters. This work presents contributions concerning the accurate dynamic SiC powerMOSFET characterization, AGD design and evaluation methodologies by means of two concrete examples, as well as control signal delivery to AGDs. The outcomes in these three subtopics are: • A Low-Inductive Test Platform for accurate dynamic characterization of SiC powerMOSFETs driven by conventional or active gate drivers, • TwoMultilevel Voltage Source Gate Drivers (MLVSGDs) offering switching slope and loss control as well as synchronous rectifier overshootvoltage suppression, and • A systematic method ofWireless Communication Technology (WCT) adaptation in Power Electronics Systems (PES) demonstrated by the example of Bluetooth Low Energy (BLE) for wireless control of an MLVSGD.