<b>Impact of modified perturb and observe control on MPPT of PV/battery fed three - port DC‐DC converter

Abstract

This paper presents the modified perturb and observe (P&O) maximum power point tracking (MPPT) method for photovoltaic (PV) fed three-port DC‐DC converter in PV/battery hybrid system. The proposed MPPT technique reduces the drift problem which occurs in the conventional MPPT methods by including the data of change in current (ΔI) in addition to the data used in the conventional P&O algorithm. The drift phenomenon and its effects are clearly demonstrated in this paper. The ability of the proposed P&O method to address this issue is proved by comparing the conventional P&O algorithm in different modes of operation. The performance assessment includes peak overshoot, settling time, MPP ratio and stability. The experimental validation was implemented using DSPIC30F4011 microcontroller. From the analysis and results, it could be seen that the modified P&O showed better performance in terms of accuracy in tracking the maximum power, less tracking time, high MPP ratio and reduced drift in the changing weather conditions.

Keywords

• current-voltage characteristics
• DC‐DC power converters
• drift
• photovoltaic systems
• power demand
• pulse width modulation.