This document presents a nonlinear current control method for a single-phase grid-connected photovoltaic (PV) system. Partial feedback linearization is used to design the controller, which linearizes the system partially and enables controller design. The controller regulates the inverter switches to track the reference current from the maximum power point tracking system. Simulation results show the proposed controller performs well under changing conditions like atmospheric changes and faults, regulating the grid current better than hysteresis control. Experimental validation of the control scheme is also presented.