GRID INTEGRATION OF SOLAR PANEL WITH POWER CONVERTERS

Abstract

This paper simulates a grid-connected photovoltaic system in MATLAB/Simulink and then a hardware implementation of the same is presented. The system consists of a PV cell, an MPPT controller, a DC/DC boost converter and a DC/AC inverter connected to a grid of 230V. The paper starts with the electrical approximation of a photovoltaic cell. The PV cell model is 40 easy, accurate, and takes external temperature and solar radiation into consideration. It also proposes two maximum power point tracking (MPPT) algorithm which are Perturb and Observe and Incremental Conductance. The algorithm incorporated in a DC/DC converter is used to track the maximum power of PV cell. Finally, the DC/AC inverter is used to regulate the output ) voltage of DC/DC boost converter and connects the PV cell to the grid. Simulation results show that the inverter current is in phase with the grid current which is of utmost importance while connecting a system to a grid. It also depicts that the model can effectively realize the actual physical characteristics of a grid-connected PV system. Next, a hardware has been implemented which uses IGBT switches to create a single phase inverter which is interfaced with a grid. For the switches, it incorporates a TLP250 optocoupler for the transfer of signals to the IGBT. The gating signals to the switches have been provided by interfacing the hardware with dSPACE DSI 104. The output obtained from the inverter shows that the grid has been interfaced properly with the inverter and can be provided to an AC load.