Step-Up/Step-Down Switched Capacitor Direct AC-AC Converter

This work introduces a patent-pending inductorless switched capacitor (SC) ac-ac converter capable of operating in either step-down or step-up mode, offering distinct voltage gains depending on how the source and load are connected to the circuit. A simple drive circuit can be used to generate three clock signals shifted by 120° for the active switches. The topology proves to be a prominent choice for replacing conventional bulky autotransformers in residential and commercial applications. The qualitative and quantitative analysis of the converter is presented in detail. A laboratory prototype rated at 110/330–330/110 V@60 Hz, 25 kHz, and 600 W is designed, whereas experimental results are thoroughly discussed to validate the theoretical claims.