A Fast and Efficient Maximum Power Tracking Combining Simplified State Estimation With Adaptive Perturb and Observe

Abstract

This paper proposes a fast and efficient maximum power tracking approach, which synthesizes simplified model-based state estimation (SMSE) with adaptive alpha perturb-and-observe (α-P&O) method, to further raise the capability and efficacy of maximum power point (MPP) tracking (MPPT). Only any two sampling points, in the first stage, on the operating characterization curve are needed to estimate the irradiance and temperature based on SMSE. In the second phase, the operation point is moved directly to the operating voltage command (OVC) derived from the fitting relationship between the voltages at MPP under various insolation intensities, and then the α -P&O method takes over the next tracking to pinpoint the exact MPP. Performances are demonstrated through simulations and experiments. Experimental results reveal that tracking accuracies exceed 99.2 % in all test scenarios. Comparing with conventional and variable step-size P&O methods, the tracking time is shortened by 84.6 % and 76.0 %, improvement of 1.26 % and 0.03 % in tracking accuracy can also be achieved, and the tracking energy loss is reduced by 68.0 % and 52.7 %, respectively.

Keywords

• Maximum power point tracking
• photovoltaic generation system
• perturb and observe
• state estimation