Modeling and Efficiency Evaluation of a Grid-Connected Solar Inverter via MATLAB/Simulink

Abstract

This study presents a simulation-based methodology for evaluating the efficiency of a grid-connected solar inverter. The proposed model emulates a complete alternating current (AC) cycle under defined solar irradiance and temperature conditions, allowing the identification of optimal electrical parameters. Specifically, for an irradiance of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$1000 ~\mathrm{W} / \mathrm{m}^{2}$</tex> and a panel temperature of 20° C, the model determines ideal operating points of 342 VDC input and 20.05 A AC output. Efficiency evaluation is conducted through two independent approaches: the first calculates the power conversion efficiency as the ratio between AC output and DC input over a full AC cycle; the second estimates internal power losses by leveraging MATLAB Simulink's component-level logging capabilities. The observed discrepancy between the two methods is primarily attributed to the integration techniques applied-namely, the use of a trapezoidal integration routine in the custom script versus a variable-step solver within the Simulink environment. The proposed simulation framework enables accurate assessment of inverter performance and provides a reproducible basis for technical validation and design optimization in photovoltaic applications.