A Dual-Function Power Decoupling Circuit for Single-Stage Grid-Connected PV Inverter
Elaheh Heydari, Ali Yazdian Varjani, Demba Diallo
Abstract
Photovoltaic energy is one of the most widespread renewable sources of electrical energy. At the heart of the power conversion system is the grid-connected interface converter based on power electronics. Single-stage systems offer higher efficiency and lower cost and size. However, they suffer from a reduced operating range due to the effects of irradiation and temperature. In addition, especially for low-power single-phase systems, pulsating power is an additional handicap. A dual-function decoupling circuit is proposed to mitigate these drawbacks. It compensates for the pulsating power and increases the lifetime of the system. In addition, the proposed low-power interface compensates for the voltage drop due to low irradiation and increases the operating range. A 1 kW test bench is designed, and experimental results show that when injecting power into the grid, the compensator attenuates 85% of the power oscillations and perfectly compensates up to 20% of the voltage drop due to low.