Driving solutions for power semiconductor devices are experiencing new challenges since the emerging wide bandgap power devices, such as silicon carbide (SiC), with superior performance become commercially available. Generally, high switching speed is desired due to the lower switching loss, yet high dv/dt and di/dt can result in elevated electromagnetic interference (EMI) emission, false-triggering, and other detrimental effects during switching transients. Active gate drivers (AGDs) have been proposed to balance the switching losses and the switching speed of each switching transient. The review of the in-existence AGD methodologies for SiC devices has not been reported yet. This review starts with the essence of the slew rate control and its significance. Then a comprehensive review categorizing the state-of-the-art AGD methodologies is presented. It is followed by a summary of the AGDs control and timing strategies. In this work, using AGD to reduce the EMI noise of a 10 kV SiC MOSFET system is reported. This work also highlights other capabilities of AGDs including reliability enhancement of power devices and rebalancing the mismatched electrical parameters of parallel- and series-connected devices. These application scenarios of AGDs are validated via simulation and experimental results.

State-of-the-art silicon carbide (SiC) power devices provide superior performance over silicon devices with much higher switching frequencies/speed and lower losses. High switching speed is preferred for achieving low switching loss, yet high dv/dt and di/dt can result in high EMI emission during switching transients. These switching dynamics can be controlled by the device gate driving strategy. The multi-level active gate driver (AGD) approach is able to tradeoff the switching losses with the dv/dt and di/dt for each switching transient. A novel three-level (3-L) AGD for SiC power mosfet trajectory control is introduced. Its turn-off profile has a shorter turn-off delay compared to any existing methodology. Accordingly, a comprehensive datasheet-driven trajectory model for the online model-based optimization of the 3-L turn-off is introduced. The main factors that impact the 3-L turn-off performance are analyzed with this model. The experimental results of double pulse tests validate the approach. Additionally, the benefits of the proposed 3-L AGD method over two-stage turn-off and conventional gate drivers on the market are illustrated through experiments.

Power semiconductor devices are often connected in parallel to increase the current rating of the power conversion systems. However, due to mismatched circuit parameters or semiconductor fabrication discrepancies, the current of paralleled power semiconductor devices can be unbalanced, which potentially leads to accelerated aging and long-term reliability issues. The fast-switching speed of silicon carbide (SiC) devices aggravates this problem due to its higher sensitivity to parasitic parameters. Numerous efforts have been dedicated to analyzing and addressing the current imbalance issue of paralleling SiC devices. This article comprehensively summarizes and presents state-of-the-art research regarding the current imbalance in paralleled SiC devices. Degree of imbalance is proposed to comprehensively quantify the current mismatch. Starting with mechanism analysis, different types of current imbalance are categorized. Various device parameters and the package layout that impact the current distribution are investigated. The existing solutions including passive methods and active methods are concluded and categorized. This work also incorporates insight into the future development needs of high-power multichip SiC module packaging and driving technologies.

Using silicon carbide (SiC) power devices can potentially improve the efficiency of the power electronic system, but it may also introduce severe electromagnetic interference (EMI) problems due to the fast switching speed. The conventional gate driver cannot provide the flexibility to adjust the switching speed of SiC dynamically. To address this issue, an intelligent versatile active gate driver (AGD) is proposed to achieve an optimized switching trajectory for power devices. The proposed AGD has five operation modes, i.e., faster/normal/slower the turn-on process and slower/normal turn-off process. The availability of multiple operation modes offers an extra freedom to improve the switching performance and enable it to be versatile. The proposed AGD can provide more switching speed adjustment resolution than the other AGDs and this feature will allow the proposed AGD to fine tune the switching speed of SiC power devices. In addition, a novel model-based trajectory optimization strategy is proposed to determine the optimal gate driver output voltage by trading the EMI noise against the switching energy losses. The functionalities of the multi-level AGD are validated with the experimental results. The hardware design consideration is also given for the product commercialization purpose.

Application of wide bandgap power devices enables the power electronics system to achieve higher efficiency, improved power density and reduced weight. Wide range LLC resonant dc/dc converters are extensively applied in multiple scenarios, such as electric vehicle charger and renewable energy generation. In this article, the design process of a high-frequency wide-range LLC resonant dc/dc converter using gallium nitride HEMTs and silicon carbide diodes is demonstrated in details. To increase the operation range, variable dc-link voltage control is utilized and investigated via analyzing the impact of the dc-link voltage on the operation point. The power loss model of the system based on the characterization results is presented and validated via simulation study. A 3.7 kW and 500 kHz experimental prototype is built to verify the proposed design process. The experimental results reveal that variable dc-link voltage control can increase power efficiency of LLC converter in all the operation range.

With the fabulous growth of the renewable energy industry, silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors ( mosfet s) are increasingly finding applications in various scenarios. To ensure the safe operation of SiC mosfet s, there is a pressing need for fast and reliable short-circuit protection methods. This article aims to give a detail overview of the existing short-circuit protection technologies for SiC mosfet s regarding their merits and limitations. First, the challenges associated with short-circuit protection are comprehensively analyzed. Subsequently, thorough comparisons of state-of-the-art short-circuit detection methods and soft turn- off strategies are conducted, respectively. Finally, this work outlines the prospects of short-circuit protection technologies in the aspects of deficiencies and optimization of short-circuit protection in multichip power module with paralleled SiC mosfet s.