Binary Search Based Flexible Power Point Tracking Algorithm for Photovoltaic Systems

Abstract

Grid-connected photovoltaic (PV) systems can provide grid support features by implementing flexible power point tracking (FPPT) strategies. Conventionally, the FPPT algorithms are based on linear search algorithms, such as perturb and observe. These solutions offer good practical results but usually lead to oscillations around the steady-state operating point. The main contribution of this article is to propose a binary search based FPPT (BNS-FPPT) algorithm. BNS is a computer-science-based searching algorithm that performs a logarithmic search within a sorted data array until the target voltage value is found. Compared to sequential searching algorithms, the proposed BNS-FPPT algorithm conducts a nonlinear search and avoids waving around the final value, reducing the steady-state error. In this article, the basics of the BNS-FPPT are described in detail. In addition, experimental results are conducted on a laboratory setup to compare the BNS-FPPT performance against a state-of-the-art solution. The results show that compared to linear search-based FPPT algorithms, the proposed BNS-FPPT is able to provide the required grid support functionalities, and avoid waving around the final operation point.