Design of a GaN-based, 9-level flying capacitor multilevel inverter with low inductance layout

Multilevel inverters such as the flying capacitor multilevel inverter (FCML) hold large potential benefit in applications where the size and weight of the inverter is constrained. This work presents the design and implementation of an inverter module which incorporates two individual 9-level FCML single-phase inverters in an interleaved design. Each inverter utilizes GaN FETs switching at 100 kHz, for an effective inductor ripple frequency of 800 kHz. The implementation features an innovative dual-sided integrated switching cell layout which decreases the effective commutation loop inductance of the inverter and enables fast switching with minimal ringing while also simplifying efficient double-sided cooling.