Grid-Connected Three-Phase Inverter System with LCL Filter: Model, Control and Experimental Results

This paper implements a grid-connected two-level three-phase inverter with both active and reactive power flow capabilities. This inverter is an effective power electronic interface for renewable energy systems. An average model is proposed for the inverter system, meanwhile the design of the current controllers is performed taking the dq reference frame into account. The system has been implemented using a NI SB-Rio development board, a high voltage DC-link, a Phase Locked Loop (PLL) algorithm, and a LCL filter. The experimental results validate and corroborate the theoretical analysis carried out.