Rede de monitoramento IoT aplicada em plantas de microgeração fotovoltaica

Abstract

The IoT monitoring network developed in this thesis project proposes the reduction of costs associated with hardware and software of dataloggers and commercial sensing modules that are imported, have high costs with control and data storage through proprietary software. Additionally, they have limited sensor connections with low expansion flexibility, restrictive maintenance to the manufacturer and long cable communication distances. The developed IoT network was implemented and tested in three photovoltaic (PV) plants grid connected: Fortaleza - CE, Maracanaú - CE and Cologne - Germany. The IoT monitoring network applied to PV microgeneration plants installed in different locations can be considered as the main innovation of this thesis project. The proposed IoT embedded systems are based on free software, allowing online distribution, free usage and communicate with a server in the Cloud wirelessly via WiFi. The use of open source and cross-platform (Linux, Windows® and Mac OSX) allows greater interaction and accessibility to the user. The proposal made it possible to program the ESP 32 remotely through OTA (over the air) and to store the data offline using the SPI Flash File System (SPIFSS) in the case of problems with the server or with WiFi connection. A web page called Web Monitor was developed for online data consultation and for real-time monitoring of the three plants. The temperature monitoring of individual PV modules has the objective of providing data for the analysis of electric generation efficiency and for failure detection in relation to the overheating of the PV cells. Meteorological data such as solar irradiance, ambient temperature, relative humidity and wind speed were also monitored to allow a more complete analysis of the effect of these variables on the temperature response of the modules. In the obtained results it was verified that the average daily irradiance from March to July 2018 in Fortaleza (4.9 to 5.5 kWh/m²) is higher than in Maracanaú (4.1 to 5.1 kWh/m²), resulting in greater electric generation in Fortaleza. The capacity factor (CF) of the plant in Fortaleza in June and July reached values around 21%, with a minimum of 16% in February, rainy season. In Maracanaú, the maximum FC was 17.5% in March and the lowest, 13.8% in May. The maximum wind speed in Maracanaú was 3.4 m/s in July and in Fortaleza, 0.55 m/s. The maximum monthly temperature of the PV modules in Fortaleza reached 65ºC, while in Maracanaú, 50ºC. Temperature measurements show that the edge of the PV module is 1.5ºC below the center.