A Single-phase Power Conditioner with a Buck-Boast-type Power Decoupling Circuit

This paper presents a novel single-phase inverter with a buck-boost-type power decoupling function suitable for PV generation. The proposed buck-boost-type power decoupling circuit enables the reduction of the peak voltage at the DC bus of the PWM inverter. This enables the use of switching devices with lower voltage ratings, and the resultant switching loss and conduction loss of the PWM inverter can be reduced. Another feature of the inverter is that a power decoupling control method based on single-phase p-q theory is applied. The proposed control method provides a low ripple current at the DC input portion, and it enables the use of small long-life capacitors such as film capacitors instead of electric capacitors. The effectiveness of the proposed system is verified by experiment with a 1 kW setup.