This paper presents High-gain power conditioning system for grid connected PV applications. The construction of the proposed system consists of high-gain Switched Inductor Quadratic Boost Inverter (SIQBI) and five-switch h-bridge inverter. The proposed system is controlled to satisfy the following criteria: extract maximum power from PV module, boost dc voltage to higher level and inject sinusoidal current in phase with the grid voltage. Proportional Resonant Controller (PRC) is used to control the inversion stage to inject sinusoidal current into the grid. Simulation results and detailed analysis are discussed in details through this paper. Experimental prototype is built, samples of the experimental results are figured out and discussed.