Integral Backstepping Control of Three phase Grid Connected Photovoltaic Systems for Power Optimization

We propose in this paper a nonlinear controller to optimize the operation of a photovoltaic device consisting of a PV generator, a three-phase inverter, and an LCL filter. Unlike traditional systems, this system is reliable and is not expensive, thanks to the absence of the DC-DC converter. In reality, we are trying to achieve two goals: (i) Search track and extract the maximum power from the PV generator (MPPT requirement); (ii) Inject this power into the network in the form of an alternating current which has the same pulsation as that of the network (UPF requirement). To achieve these objectives, the proposed controller was designed using non-linear design techniques, based on the nonlinear modeling of the photovoltaic system. Numerical simulation and its results showed the performance of the nonlinear controller and its ability to confront the challenges described in this article (MPP and UPF requirement), external disturbances and abrupt climatic changes.