A Switched-Capacitor Based Single-Stage Multi-Port DC Collector for Wave Energy

Wave energy is a typical renewable energy, transferred into electric energy by permanent magnet synchronous generator (PMSG), and integrated in DC form. Thus, this paper proposes a switched-capacitor based single-stage multi-port DC collector for wave energy. A single-stage step down converter based on switched-capacitor is proposed as submodule, by integrating and simplifying the traditional two-stage converter by buck converter and switched-capacitor converter. The large electrolytic capacitor for DC voltage is eliminated, and the interleaving buck converter is employed to achieve a high voltage gain and high power delivery, due to the complementary conduction in series switches in switched-capacitor converter. Moreover, the high voltage ports of submodules are series to achieve a higher DC voltage, and the low voltage ports are distributed for multiple generators. The operation frequencies for switched-capacitor and buck modules are independent to achieve a wide voltage range. Then, the characteristics of proposed multiport collector are discussed, such as voltage gain, power delivery, voltage stress. Finally, the stable operation and comparison results are discussed to verify the correct and effect of proposed multi-port DC collector.