Diseño y simulación de un sistema fotovoltaico de dos etapas acoplado a la red eléctrica trifásica.

Abstract

This work presents the design and simulation of a two-stage three phase PV system connected to the grid. The system consists of a photovoltaic panel connected to a DC-DC SEPIC converter which is responsible for energizing a two-level three-phase DC-AC inverter that is connected to the grid through an L filter. The design of this system consists in the analysis of the SEPIC converter with the sizing of the elements that make it up. This converter is controlled by a Maximum Power Point tracking algorithm (MPPT) that measures the voltage and current of the PV panel. Based on these measurements, the algorithm calculates the working relationship that the DC-DC converter must work with, to extract the maximum power from the photovoltaic panel at any irradiance and temperature. The design of the inverter consists in the analysis of the switching states that must be carried out using the SVPWM modulation technique to generate sine currents and voltages at the output of the inverter and the sizing of the filter. The inverter is controlled by a cascade loop technique, where the internal loop controls the current that is injected into the grid in both, the rotational and stationary reference frames, finally the external loop is responsible to control the input voltage of the inverter. In order to simulate the system and check its efficiency and energy quality injected to the grid Matlab-Simulink software is used.