Estudio comparativo de técnicas de control PI y difuso para la estabilidad de tensión de un inversor trifásico en sistemas fotovoltaicos, evaluando el voltaje en estado transitorio y estable

Abstract

This paper deals with a comparative study of two different control methods implemented to improve the voltage quality at the output of a three-phase photovoltaic DC/AC inverter. The study applies a classical PI control and a heuristic control by fuzzy logic, both independently controlling the duty cycle (PWM). For the comparison of the two controllers, three experimental cases have been considered, in each one the environmental conditions of temperature and irradiance of the photovoltaic panel have been modified. As a result of the investigation it was concluded that the fuzzy controller presents better quality, because its steady state error values are below 0.133%, on the other hand, its characteristic values such as peak voltage, over peak time and settling time, are more favorable than the classical PI control. The design of the controllers and the system has been implemented in Matlab-Simulink software, suitable for modeling dynamic systems. Finally, the use of fuzzy control is recommended for its advantages of stability at medium voltage levels, suitable for industrial applications.