A method of power decoupling for long life micro-inverter

In this paper, the relationship between voltages of the decoupling capacitor and its value is investigated. It demonstrates the natural way to reduce size of decoupling capacitor is intentionally increasing capacitor voltage. As a result, film capacitors can be adopted instead of electrolytic ones and a long life power supply is achieved. An auxiliary circuit added into a photovoltaic grid-connected micro-inverter is studied, and the capacitor in it can endure higher voltage than that PV panel outputs. Therefore, power decoupling function and small value of capacitors are reached. Moreover, a control method based on this system is also analyzed in details. Finally, the effectiveness of the inverter is confirmed through PSIM simulation on a 100W system.