System identification-based MPPT algorithm for PV systems under variable atmosphere conditions using current sensorless approach

摘要

In photovoltaic power systems operating under variable atmospheric conditions, the success of maximum power point tracking (MPPT) methods is very important for efficiency. Therefore, many different MPPT methods have been developed in the literature. The voltage-controlled MPPT method is one of the oldest methods that is easy to implement but operates with low efficiency in variable weather conditions. At variable radiation and temperature values, the voltage value that the system must generate in order to capture the MPP point was obtained by modeling the PV system by the system identification. Thus, using only system input and output information, a model was created without the need for system parameters. In this study, system modeling was performed using the Wavenet nonlinear function. The output of the system model gives the reference voltage required to capture the MPP point. Thus, the reference input voltage of the MPPT was made adaptive against changing weather conditions. By using the proposed voltage controlled MPPT method and the other conventional methods such as Incremental Conductance (IC), Perturb and Observe (PO), and Constant Voltage Controller(CVC) methods, various simulations (3 different scenario) were performed in Matlab/Simulink environment. The results obtained from simulations carried out for three different weather conditions were given comparatively. The performance of the proposed method was analyzed in detail at the change points of the temperature and radiation values, and at some other regions.