Smart GaN-Based Inverters for Grid-tied Energy Storage Systems

Battery storage systems provide distributed energy storage capabilities for smoothing the load profile and coping with power fluctuations.A challenge in the utilization of battery systems is the manufacturing of high efficiency battery inverters.Traditional Silicon-based inverters do not offer high efficiencies and suffer from larger real estate requirements.Recent commercialization of low-cost Gallium-Nitride (GaN) and Silicon-Carbide (SiC) semiconductors has opened up an opportunity to manufacture high efficiency inverters that can operate at higher switching frequencies and demand smaller filtering elements.To this end, InnoCit proposed a modular smart GaN-based inverter (Ganverter) for integration of battery systems into industrial/residential 480Vac grids.During Phase I/II projects, InnoCit was able to design, develop, and demonstrate gird-tied battery inverters with both GaN and Silicone-Carbide (Sicverter, SiC, in addition to the original scope of the Phase II grant) technologies.InnoCit’s solutions offer a bidirectional transfer of 20kW between a 900Vdc battery rack and a 3-phase 480Vac grid in 3U rack chassis.Additionally, up to 10 Ganverter/Sicverters can be paralleled to achieve power levels of up to 200kW.InnoCit has successfully developed and tested the deliverables of its Phase II project and is currently working towards the final enclosure design and commercialization of the Ganverter.Currently, Ganverter is at TRL 7.The aim of this Phase IIB is to achieve a TRL 8 status with all the required certifications completed and to have the commercialization started during this Phase IIB project.In this Phase IIB project, InnoCit will finalize its design and perform in-house/3rd party lab.testing for UL/ETL certifications required for mass commercialization of Ganverter.Additionally, the final enclosure which is based on a standard IT rack will be developed.An objective of this Phase IIB project is to work with a rack manufacturer to develop a manufacturing plan/supply chain for Ganverter chassis.Lastly, a central controller and user interface will be developed to allow for local/remote control and monitoring of Ganverter.InnoCit’s Ganverter and Sicverter utilize printed circuit board-based design to minimize the wiring within the circuit to reduce the labor-intensive manufacturing processes.Modular 20kW units offer the user a variety of output power selections from 20kW up to 200kW per each central controller.As a result, instead of manufacturing multiple units at different power levels, our modular solution reduces the manufacturing cost and provide the user with the flexibility of selecting the right capacity for their application.Lastly, our solution is offered in both GaN and SiC technologies to minimize the risks associated with long term reliability concerns of wide bandgap technologies.Our GaN solution offers a CEC efficiency of 99% while our SiC solution offers a lower cost.Additionally, our modular design allows the user to utilize multiple battery racks/technologies as oppose to a single battery chemistry.Each 20kW unit can have a dedicated battery input while controlled in harmony with the rest of the system.Hence, Ganverter provides a better battery rack balancing and a higher availability compared to off-the-shelf products.