Active Power-Decoupling Methods for Photovoltaic-Connected Applications: An Overview

Abstract

This study compares ripple port, stacked switched capacitor, and capacitive energy storage architectures for active power decoupling, comparing the number of components, performance, energy density, DC-link capacitor reduction, efficiency, and frequency operation to highlight their main benefits and drawbacks for single-phase grid-connected applications. The overview reveals equivalent effective energy density without electrolytic capacitors, as well as enhanced simplicity, performance, and durability, thereby providing stacked switched capacitors as an attractive power-decoupling alternative for multi-stage connected applications, based on the principle that its individual buffer capacitors absorb and deliver energy without tightly constraining their individual terminal voltages, while maintaining a narrow range voltage at the buffer DC port.

A New LCL Filter Design Method for Single-Phase Photovoltaic Systems Connected to the Grid via Micro-Inverters

“…The basic block diagram of a typical single-phase PV is shown in Figure 1. This system consists of a photovoltaic panel, a DC-DC converter, a link capacitor between the DC-DC converter and the inverter, an output filter, and the grid [4,7]. The blocks shown are those present in a commercial PV system.…”