In this paper a maximum power point hacking (MPPT) system based on the single ended primary
inductor converter (SEPIC) and hill-climbimg approach is introduced. 'SEPIC converter is a
comprehensive buck-boost converter and has minimum ripple content in the input current that
suitable for PV application. The proposed MPPT system is designed and components of SEPIC
converter are sized and selected. The conholler is so fast and no fluctuation around the MPP is
introduced. A current and voltage of the PV array are sensed and a pulse width modulation (PWM)
signal is produced from the controller to conhol the duty ratio of the converter. The simulation
results show that three tests are carried out on the system; a suddenly insolation level increasing,
decreasing, and load resistance variation. The controller establishes robustness for all the three
cases and the maximum power available fiom the PV array are transferred to the load irrespective
of load or environmental condition variations.