Geometrical Interpretation of Incremental Conductance MPPT Algorithm for a Stand-alone Photovoltaic System

This paper explores the geometrical interpretation of incremental conductance (INC) maximum power point tracking (MPPT) technique for a stand-alone photovoltaic (PV) system. The geometrical analysis is done considering I-V characteristic curve of the PV module. It depicts how the maximum power operating point (MPOP) shifts on the I-V curve under different operating conditions. Though, several research have been done to explain the mathematical aspect of the algorithm through equations and flowcharts, a graphical interpretation will help in visual realization of the core concepts of the MPPT algorithm. Furthermore, the geometrical analysis considers both constant and varying irradiance conditions to validate this approach. Also, simulation and experimental study of INC MPPT algorithm is carried out to check its functionality in real-time using the dSPACE rti1103 digital controller. The steady-state and transient behaviour of the algorithm is analyzed during varied irradiance and load change condition. Both simulation and experimental results confirm that classical INC algorithm works fine under varying operating conditions.