An Adaptive Sensorless Control Technique for a Flyback-Type Solar Tile Microinverter

Abstract

This article presents a novel sensorless control system for a solar tile microinverter employing the flyback topology. The elimination of current sensors from the circuit lowers the overall cost and reduces measurement noise introduced into the control system. The proposed control system eliminates both the high frequency inductor current measurement as well as the photovoltaic (PV) module current measurement. Additionally, an inductance observer is combined with the proposed technique to increase the accuracy of the high frequency inductor current estimation. A stability analysis proves the system to be stable. The proposed control system is experimentally validated on a microinverter prototype. Simulation and experimental results affirm the feasibility and performance of the control system. The experimental setup includes a grid simulator and a PV module simulator to test the system at varying irradiance levels. The proposed control system is also compared to methods presented in previous literature to demonstrate its superior characteristics.