Desenvolvimento de uma plataforma para medição de consumo de energia elétrica com monitoramento via sistema web

Abstract

Residential customers have no control over energy quality in their consumer units, because this task is left to the regulatory bodies. Electrical equipment can, for various reasons, present a faulty, causing efficiency losses and an increase in energy consumption. Solutions capable of evaluating the behaviorwith respect to electrical quantities can, above all, be useful in diagnosing a possible problems, avoiding energy waste and accidents. Since most electrical instrumentation equipment is not capable of measuring different quantities simultaneously and energy analysis devices are expensive, solutions linked to the Internet of Things are alternatives to be explored for residential energy monitoring. Methods for measuring electrical quantities differ in terms of signal collection and how these data should be treated after being measured. In this work, a step-down transformer and a current sensor based on the Hall effect were used to measure voltage and electric current, respectively. A prototype capable of measuring energy consumption in equipments connected to a low-voltage network, at 220 V RMS, was built using a PIC microcontroller, for data collection and processing, communicating with a device capable of providing information on a private internet network to be accessed by a web application used as a visualization interface. The RMS values of voltage and current were calculated, and the power factor, as it is an important parameter in energy efficiency. Tests with linear loads, with resistive and reactive property, were carried out in order to verify the behavior of the prototype in different situations. The obtained results were compared with theoretical calculations, multimeter and oscilloscope. In general, errors related to voltage and current were around 5% in most tests. In the case of current, the best results were found for loads with consumption greater than 1 A. The power factor calculation method, using the microcontroller comparator module, showed results with waveforms consistent with the phase difference of the measured signals.