Robust low cost energy meter

This paper consists of the development of a robust low-cost energy meter. The paper aims to use an alternative method to the one existing for reading currents with high slopes, this existing method consists on capturing the high-frequency components. Focusing in the lower frequencies provides a robust yet accurate reading, as most of the power is contained in the fundamental frequency. This new approach provides robustness against electromagnetic interferences and allows to use lower-cost components. An ESP32 microcontroller programmed in C is used to get the readings from a low- cost current transducer (SEN0211) and a differential voltage probe. Some experiments with traditional linear loads and modern non-linear loads are made to validate the system. The deviations obtained stay under 1% in linear loads and range between 3.24% to 74% for the most complex non-linear load setups, probably due to the low sampling frequency used. The paper discusses the project’s design, measurements and results, giving explanations and guidelines for better understanding and future improvements in these measurements.