Analysis of a Switched-Capacitor Converter with Output Voltage Regulation and Soft Switching Capabilities

High power density of switched-capacitor converters (SCCs) is due to absent of inductive components. But, this subject leads to output voltage regulation problem and hard switching characteristics due to high current spikes, which increase switching losses and noise and limit the power rating. Although, performances of some SCCs have been improved recently by including some small inductors in their topologies, but, only few of them can regulate output voltage and have soft switching characteristics. Here, by combining an active clamp and a boost SCC, both output voltage regulation and soft switching characteristics are achieved, even when wide input voltage and load variations are applied. So, switching frequency can be increased to reduce inductors and capacitors values, due to low switching losses and noise. It reduces the converter volume and also improves its performance, because small inductors and capacitors have better high-frequency characteristics, practically. Therefore, the modified converter is practically much better than the conventional configuration, especially at high power ratings. Here, the modified converter has been analyzed, mathematically, and to verify the given analyses, it has been simulated and implemented at 200kHz for regulating a 400V output voltage, even when wide input voltage (50-100V) and load (400Ω-8kΩ) variations are applied.