In this paper a modified BOOST converter is presented for maximum power point tracking (MPPT) with PI
controller to improve the performance of PV system. SEPI converter is proposed as interface between load and
PV module array as DC-DC converter. Whichis more advantageous over boost converter for step up and step
down operations. The P&O and PSO based BOOST converter proposed are main key factors for high
efficiency output at foul weather conditions. The MATLAB/SIMULINK power system tool box will be used to
stimulate the proposed system.