Control of a Grid-connected Inverter using Sliding Mode Control

Abstract

The rising popularity of grid-connected multilevel inverters with photovoltaic panels underscores the importance of effective modulation and control strategies for ensuring optimal power quality. The performance of these inverters hinges significantly on modulation and control approaches, specifically addressing issues like common mode voltage, harmonics, switching loss, and dynamic response. This study introduces a novel approach to mitigate current harmonics in these inverters by employing sliding mode control. Notably, this technique achieves harmonic reduction without necessitating an increase in the switching count. The presented technique eliminates phase-locked loop, current controllers, and carrier waves, thereby easing hardware computation. Beyond computational efficiency, this approach contributes to enhanced power quality and dynamic response within the inverter system. Simulation results affirm the efficacy of the proposed method when compared to the use of the phase opposite disposition modulation combined with the current controllers. In the nominal operational mode, the proposed method reduces the current Total Harmonic Distortion (THD), the highest magnitude of individual harmonics, and the switching count by 43.6%, 73.5%, and 19.6% respectively, compared with those of the method using the phase opposite disposition modulation combined with current controllers.