A novel voltage-current characteristic based global maximum power point tracking algorithm in photovoltaic systems

This paper presents a new global maximum power point tracking algorithm based on the voltage-current characteristic curves of solar panels. This algorithm consists of two sub algorithms that are used in uniform irradiance and partial shading conditions. First, voltages of the bypass diodes are measured for checking the partial shading condition. In the sub algorithm developed for uniform irradiance conditions, convergence time is reduced by suggesting a new approach based on the ratio of current of maximum power point and short circuit current. With the help of this ratio, proper initialization of duty ratio is aimed. On the other hand, a novel approach is introduced by employing average equivalent resistance of solar panel for the purpose of global maximum power point tracking in partial shading conditions. In this approach, characteristics of solar panels are used. So as to validate the performance of the proposed algorithms, a single ended primary inductance converter is modelled in MATLAB/Simulink. Simulation results show that proposed algorithm finds the global maximum power point in partial shading. It operates faster than P&O in uniform irradiance condition. It is worth noting that sub algorithm developed for partial shading can be used in uniform irradiance condition. It performs better than P&O algorithm in this condition.