Linearly Scalable Cost-efficient Parallel Method for High-power Wide-bandgap-based Converters

The emergence of wide bandgap (WBG) power devices promises to revolutionize next-generation high-power converters for applications such as electrified transportations and renewable energy systems. Therefore, paralleling operation either at device level or converter level is essential. However, parallel-connected devices cannot utilize the full capability due to current imbalance and switching-speed reduction, while converters in parallel lead to the bulky interphase inductor and complex control because of circulating current. To maximize the value of individual WBG device in high-power converters, this paper proposes a linearly scalable cost-efficient parallel method enabled by WBG-based functional block with decoupling filter and gate drive network First, the architecture of this method together with its features is presented. Then, the design methodology is given. Finally, a case study is performed using Synopsys/Saber simulation with a silicon carbide (SiC) MOSFET behavior model. The results show that using the proposed parallel method, the dynamic current imbalance is less than 1% versus 11% of the device-level parallel solution while inductors used for suppressing circulating current have 2-3 orders of magnitude reduction as compared to the converter-level parallel. Also, no dedicated control is needed for the proposed solution.