Research
Flying Capacitor Multilevel Converters in DC-AC/AC-DC Applications
The flying capacitor multilevel (FCML) converter is a type of hybrid switched capacitor converter that is known for high efficiencies and volumetric power densities. This is accomplished through the use of lower voltage, high figure-of-merit switching devices. The FCML converter performs much of its energy conditioning via energy-dense capacitors that enable higher volumetric power densities, which is essential in volume-sensitive applications such as electrified transportation. In some of my work, I have explored how variable switching frequencies can be used to improve converter efficiency without violating key component current and voltage ripple constraints.
6-level gallium-nitride based FCML inverter used in a 2-stage microinverter solution.
Electromagnetic Interference for High Performance Converters
Electromagnetic interference (EMI) is critical in all application where power converters are connected to other equipment. In my work I have explored how EMI can be improved through variable frequency control in FCML converters. I have additionally analyzed fundamental EMI generation for FCML converters, and developed analytical models describing this.
EMI test bench.
EMI scan results showing the reduction in switching-frequency harmonic peaks as a result of variable frequency control.