Microcontroller Implementation of an MPPT Algorithm using Decremented Windows Size Scanning Method for Photovoltaic Systems

Abstract

This paper presents a hardware implementation of MPPT algorithm. SEPIC converter is proposed and designed as DC/DC converter. The control unit for MPPT using P&O based algorithm is namely decremented window/frame-size scanning. The global MPP is tracked by the MPPT algorithm by reducing the frame size of the domain scanning for every iteration. Duty cycle of a pulse-width modulation (PWM) signal is used as the scanning unit. The circuit performance monitoring is made by using an interface software that can generate real-time graphics. The system is real tested under three partial shading scenarios. The result shows that the MPPT circuit can reach maximum efficiency of 85 %. The number of iterative frame reduction step to reach global MPP is about 3 steps with 33 ms to finish all steps.