The development of power electronic converters has brought tremendous change in photovoltaic (PV) system. The input voltage of converter is flexible compared to input current but it is more influenced by the nonlinearity in the PV characteristics under different climatic conditions. In this paper the flexible input voltage is controlled by employing cascade control technique in the PV Stand-alone system. First, the input voltage across the capacitor and the current through inductor of the converter are controlled by retaining linear cascade controller, which is liberalized by the PV Characteristics obtained by maximum power point (MPP) by the state space modeling. Finally, the PV System has instability, when the converter is operating at constant current region (CCR) and this problem poses a challenge to control the design. So as to resolve this issue, a non-linear control with Feedback Linearization Control (FBLC) technique is applied to the converter system. The control laws are derived and implemented to the boost converter. The result reflects better performance in the proposed FBLC technique, which is not influenced by PV operating conditions.