A boost converter‐based MPPT steady‐state oscillation‐free fast tracking control strategy for photovoltaic power systems

Abstract

Abstract With the conventional perturbation and observation (P&O) method, photovoltaic (PV) converters have long maximum power point (MPP) tracking times and three‐point oscillations at the steady state that can lead to output power losses and inefficiencies in grid connections. To overcome these drawbacks, a fast tracking and steady‐state‐oscillation‐free control strategy is proposed. The strategy first stores four random duty cycle values on the basis of the duty cycle variation characteristics of the PV panel power adjustment, then calculates the odd and even duty cycle difference and judges the steady state by varying the duty cycle difference threshold. The strategy next obtains the MPP duty cycle using a median filtering algorithm (MFA) to suppress the steady‐state oscillation and improves the tracking speed by resetting the appropriate duty cycle step according to the slope of the PV curve of the PV panel output and the corresponding adaptive coefficients. The proposed algorithm was simulated and experimentally validated under various irradiance conditions, and the results show that the algorithm can improve the PV panel output efficiency compared to both the conventional P&O and the adaptive P&O methods.