Photovoltaic Cell (PV) is an environment-friendly source for electric power generation. A photovoltaic module (combination of PV cells) exhibit nonlinear V-I characteristics and maximum power points (MPP), that vary with solar insolation. Also, the PV module offers some impedance which does not match the impedance of the load. So, with the varying maximum power points, and mismatched impedance, load unable to extract maximum power that solar module generates in full day, due to which the overall efficiency of PV system decreases. To extract maximum power from the solar module, it is needed to operate the photovoltaic (PV) system always at the maximum power point (MPP) which is unique for every insolation and match the load impedance with PV module impedance. An intermediate circuit known as MPPT circuit can, therefore, maintain this operating point at MPP and hence ultimately increase the overall efficiency of the system. MPPT device when used with dc-dc converter matches the PV module impedance to the impedance offered by load and maintain the load line of the load at MPP line. This is known as Maximum Power Point Tracking (MPPT). This paper shows a system which provides maximum power to the load at every insolation. We present a simple circuit model of the dc/dc buck-boost converter connected to the photovoltaic systems controlled by incremental conductance algorithm of MPPT. The model has been implemented in PSIM (Powersim).