The diversification of the energy matrix in the countries around the world establishes a leadership role in the supply of renewable energy to photovoltaic and wind energy, so it is necessary to know precisely the model of the photovoltaic system in order to improve the conditions of operation and maintenance. This research work includes the methodologies to determine the characteristic parameters of the single-diode photovoltaic model using well-known methods in the scientific literature. The focus in this research is based on determining the accuracy of the methods, so a comparison between the measured power and the power values provided by the mathematical model was made, this work uses experimental data: irradiance, temperature, voltage and power, these were collected from on-grid 3 kWp photovoltaic system. The experimental information applied to the mathematical models and the values of the statistical indicators made it possible to determine the accuracy of the methods in partly cloudy sky and cloudless sky.