High induction, power dense transformers to enable adoption of SiC and GaN power electronic devices

The development of wide bandgap (WBG) devices, especially the silicon carbide (SiC) MOSFETs, enables new possibilities for power electronics conversion and integration in solar applications. Compared with their silicon counterparts, the fast switching speed and low switching loss of SiC devices allows for higher switching frequency, which leads to volume reduction on passives. Moreover, with similar power rating, the footprint of the SiC power module can be much smaller than the Si modules. In addition, the high temperature operating capability of SiC devices can also increase the converter system reliability. However, over the past years, the high cost of the SiC chips and/or modules is one of the major obstacles for adoption in the solar inverters. Recently, because of the booming electric vehicle industry, prices of the low voltage SiC chips, e.g., 900V and 1200V, are dropping significantly. Cost effective SiC based traction inverters have been adopted in many vehicle models from various automakers. This creates an opportunity for next-generation power electronics components in the solar industry to be designed around low-cost SiC devices and state-of-art high frequency magnetics. In addition, combined with advanced inverter topologies, such as isolated multi-port converters and solid-state transformers (SST), high performance transformerless PV-SST, as shown in Fig. 1(a), with advanced grid features can be compelling alternatives to today’s industry standard silicon-based inverters. In this project, the goal is to develop and demonstrate a high density high power isolated DC/AC converter, i.e., the Power Cell, which is the essential building block for the PV-SST system, through the use of the best in class planar form factor magnetics, SiC power electronic technology and a multi-objective electro-magnetic-thermal co-design approach. The objectives of the proposed program are to facilitate the commercialization of advanced power electronics converters for solar integration applications through enhancing the performance of current state-of-art with best in class and emerging nanocrystalline based soft magnetics.