Improved transient response control strategy and design considerations for switched-capacitor (SC) energy buffer architectures

Switched-capacitor (SC) techniques have been proposed for energy buffering applications between DC and AC grids. These techniques have been implemented using film or ceramic capacitors and have been shown to achieve high energy utilization and comparable effective energy density to electrolytic capacitors. Practical applications require control schemes capable of handling transients. This paper takes a comprehensive view of the SC energy buffer design space and examines tradeoffs regarding circuit topology, switching configuration, and control complexity. A two-step control methodology that mitigates undesirable transient responses is proposed.