Conductive EMI Attenuation of GaN-Based Bi-Directional Grid-Tie Inverter for Ultra-High-Speed PMSM Application

The integration of WBG based high frequency inverters with ultra-high speed Permanent Magnet Synchronous Machines (PMSMs) presents unique challenges in managing Electromagnetic Interference (EMI), crucial for ensuring electromagnetic compatibility (EMC). This work presents the design and validation of EMI filters for a high frequency WBG-based bi-directional grid-tie inverter, specifically developed for ultra-high-speed PMSM applications. Without EMI filter, the inverter cannot meet the conducted emission limits in the relevant standards. By Utilizing the grid and machine side filters, the system complies within the strictest category 1 limits of IEC61800-3 for use in residential areas. Test results confirm that the new filter significantly enhances electromagnetic compatibility, reducing EMI below industry limits while maintaining inverter efficiency and dynamic response. The inverter developed and experiments conducted on ultra-high-speed 180,000 rpm, 3 kW, with 400V DC link developed on both SiC and GaN switching at 100kHz. The work’s outcomes not only further the integration of high-speed PMSMs into smart grids but also pave the way for future innovations in power electronics design. This work is expected to facilitate the wider adoption of WBG technology in critical energy infrastructure.