MPPT and PFC achievement in grid connected photovoltaic system based on a half bridge inverter

We consider the problem of controlling single-phase grid connected photovoltaic system based on a half bridge inverter. The control objectives are threefold: i) Maximum power point tracking (MPPT) of PV system. ii) Unity power factor in the grid. iii) Regulating the output voltage to a desired reference value. The considered problem is dealt with by designing a nonlinear controller using the sliding mode strategy based on an averaged nonlinear model of the overall controlled system. The system configuration includes a photovoltaic generator, DC-DC converter, DC-AC half bridge inverter coupled to grid. The system is controlling by acting on the control inputs of the boost chopper and the half bridge inverter. The performance of the proposed controller is evaluated through numerical simulation in terms of delivering maximum power and synchronization of grid current with grid voltage under changes in atmospheric conditions. It is easy to show, that the proposed controller achieves its objectives, through theoretical analysis and simulation results.