A Novel Maximum Power Point Estimation Algorithm for PV System Using Real-Time Short Circuit Current Calculation

Abstract

At the maximum power point (MPP), a photovoltaic (PV) system output voltage $(V_{MP})$ fluctuates in steady state due to a perturbing nature of its controlling algorithm, and unnecessarily causes power loss. To overcome this problem, the PV system must operate with a steady value of $V_{MP}$. This paper presents a solution to obtain a steady value of $V_{MP}$ in real-time. First, a real-time short-circuit current $(I_{SC})$ is determined using a power-law relation between the current and voltage of a PV module irrespective of the irradiance. Then, using $I_{SC}$, the value of $V_{MP}$ is obtained from a predetermined exponential relation between $I_{SC}$ and $V_{MP}$. The short-circuit current driven MPP (SCC-MPP) algorithm is examined using experimental tests for a 160 W polycrystalline silicon module connected to a resistive load through a boost converter. The SCC-MPP algorithm exhibits excellent performance than perturb and observe (P&O) algorithm in varying irradiance and a sudden load change conditions.