Performance of an Anisotropic Magneto-Resistive Sensor Electrical Energy Meter

This paper presents a digital electrical energy meter based on an Anisotropic Magneto-Resistive (AMR) current sensor and an Arduino micro microcontroller. This study aimed at designing and fabricating a digital electrical energy meter using the AMR sensor which overcomes some of the shortcomings of traditional current sensors used in most energy meters, display electrical energy, consumer‟s terminal voltage, supply current, power factor and „real-time‟ power consumption. The study was carried out in the Department of Electrical and Control Engineering, Egerton University between September 2018 and December 2020. The meter was designed using Proteus 8 Professional software and fabricated on a printed circuit board. Algorithms were developed in C-language and stored in the microcontroller to continuously sample voltage and current signals derived from a successive supply voltage divider and the AMR current sensor, respectively. The sampling frequency was 2 kHz and every 10,000 samples were carried out to compute the Root Mean Square (RMS) values of voltage and current. The fabricated meter digitally computed the cumulative electrical energy in kilo-Watt-hours (kWhrs) and the other variables and displayed them on a 16×2 Liquid Crystal Display (LCD) after a consumption of every 0.01 kWhrs. Statistical results on the displayed variables indicated that the meters tested were not significantly different at 0.95 confidence level implying that those meters had similar performance. The extra displays are important and useful to power consumers and service providers in energy utilization and improvement of the quality of the power supplied. Power factor is an exceptional feature in the prototype meter beneficial to both consumers and power agencies in the decision-making process of reducing bills and power distribution costs leading to improved efficiency and service delivery.