Experimental Evaluation of Internal Model Control for 3ϕ Grid-tied Solar PV Inverter

Abstract

The control performance of the 3-phase grid inverter decides the quality and quantity of power transfer from solar panels to the utility grid. Therefore, performance enhancement of control techniques of grid-tied photovoltaic system has practical significance. The objective of this work is to enhance servo control of the grid-tied PV system using a multi-variable internal model control (IMC) technique. The design guidelines of IMC for the grid-tied photovoltaic system is clearly presented. The filter model of the voltage source inverter is employed to design the IMC. Experimental results are demonstrated for two conditions. In one of the conditions, cascaded control of DC-link capacitor voltage and grid current has been carried out. The current reference for the IMC is generated from the PI controller which controls the capacitor voltage. Maximum power of the PV is tracked by generating suitable reference voltage for the DC-link voltage control. In the other condition, only IMC performance is verified assuming constant DC source. The experimental setup is explained in detail and concluding remarks are presented.