Compact Single-Stage Micro-Inverter with Advanced Control Schemes for Photovoltaic Systems

• Main Authors: Yoon-Geol Choi, Hyeon-Seok Lee, Bongkoo Kang, Su-Chang Lee, Sang-Jin Yoon
• Format: Article
• Language: English
• Published: MDPI AG 2019-03-01
• Series: Energies
• Subjects: single stage micro-inverter; burst control; variable frequency control; maximum power-point tracking
• Online Access: https://www.mdpi.com/1996-1073/12/7/1234

This paper proposes a grid-connected single-stage micro-inverter with low cost, small size, and high efficiency to drive a 320 W class photovoltaic panel. This micro-inverter has a new and advanced topology that consists of an interleaved boost converter, a full-bridge converter, and a voltage doubler. Variable switching frequency and advanced burst control schemes were devised and implemented. A 320 W prototype micro-inverter was very compact and slim with 60-mm width, 310-mm length, and 30-mm height. In evaluations, the proposed micro-inverter achieved CEC weighted efficiency of 95.55%, MPPT efficiency >95% over the entire load range, and THD 2.65% at the rated power. The proposed micro-inverter is well suited for photovoltaic micro-inverter applications that require low cost, small size, high efficiency, and low noise.