Analysis and output voltage control of a cascaded switched-capacitor converter under ZVS condition

Abstract

Performance analysis and output voltage regulation of a cascaded step-up switched-capacitor converter (SCC) under zero voltage switching (ZVS) condition is analyzed in this paper. The ZVS condition (converter operation above its resonant frequency) provides 1) zero-voltage switching, which leads to a relatively higher efficiency compared to zero current switching (ZCS) under the resonant frequency in MOSFET-based converters and 2) operating in a higher frequency, which reduces the size and increases the power density of the converter. It also provides output voltage regulation compared with previously proposed SCCs in ZCS condition. This paper proposed a cascaded switched-capacitor converter (CSCC) that provides a high voltage gain. For this structure, it proposes a mathematical analysis to calculate the output voltage characteristics of the converter. This study is then employed to design a control loop for the output voltage of the converter. The simulation results for a 110–160 V and 500W SCC converter confirm the proposed analysis and the designed control loop.