Performance Comparison of Stand Alone Solar PV System with Variable Step Size MPPT

Abstract

The maximum output power generated by the Photo Voltaic (PV) module varies with the environmental condition like irradiance and temperature. This drawback along with its low energy efficiency no way can provide reliable electric energy to the consumer. The role of maximum power point tracking technique in transferring maximum available power to the electric load under any environmental condition of the PV module is remarkable. The requirement of electric load to fetch the maximum power from a PV source under any input condition can be attained by including a power interface in the system.  The role of this power interface, the converter is to make its input impedance constant irrespective of the change in load. The purpose of transferring maximum power to load is achieved by the incorporation of a Maximum Power Point Tracking (MPPT) controller in the PV system. In this paper, a standalone PV system is modelled with three different converters topologies and its performance is analyzed using variable step size MPPT.  Performance comparison is done in terms of input current ripple, output voltage ripple, output power ripple and efficiency. A detailed simulation is done for different conditions of environment in MATLAB/Simulink and the results obtained are presented in this paper.