Development of a low-cost monitoring system for the measurement of DC and AC electrical parameters in grid-connected photovoltaic systems based on IEC standards

Abstract

The rapid development of renewable energy sources, such as photovoltaic solar energy, makes it possible to sustainably cover part of the energy demand in different parts of the world. Thus, higher efficiency of photovoltaic systems is sought to provide higher yields, security, and stability in their operation and energy production. Therefore, it is crucial to monitor the variables of interest and verify the correct operation of photovoltaic systems. This article presents the development of a monitoring system that allows the acquisition and recording of the main electrical parameters, both in direct and alternating current, enabling the evaluation of the array and final yield of grid-connected photovoltaic systems. The developed monitoring system follows the concept of the Internet of Things for remote data analysis. In addition, it allows local data logging in a computer for data acquisition over a long period. The measurements of the developed monitoring system comply with the International Electrotechnical Commission standards specified in IEC 61724-1. This validation is performed after contrasting the measurements obtained by the developed system with those obtained by the high-precision WT5000 power analyzer, where the relative differences of each electrical parameter analysed are less than 2%. Finally, the system developed is characterised by its low cost, which is less than US$ 140.