MPPT ALGORITHM USING DECREMENTED WINDOW-SCANNING METHOD FOR HOME SCALE PHOTOVOLTAIC-BASED POWER SUPPLY SYSTEMS

This paper presents a hardware implementation of a novel method to operate
a photovoltaic-based electric power system at its maximum power point. A maximum
power point tracing (MPPT) algorithm named decremented window-scanning (DWS) is
proposed and validated in real experiments. The scanning process operates based on
perturbing signal with variable duty ratios of the pulse-width modulated signal applied to a
DC-DC converter circuit in the MPPT module. The characteristic of the proposed MPPT
algorithm is its simplicity to implement on a microcontroller device. It consumes 11,518
bytes memory, or 37% of total 30,720 byte available memory slots in the microcontroller.
The MPPT algorithm is tested using 100Wp photovoltaic (PV) panel under three different
partial shading conditions. The experimental results show that the MPPT unit can find
the expected duty ratios that can turn the PV unit to operate at its maximum power
points.
Keywords: Maximum power point tracing (MPPT) algorithm, Power electronics, Scanning-based MPPT algorithm, Photovoltaic systems, Decremented window-scanning