Non-Destructive Current Sensing for Energy Efficiency Monitoring in Buildings with Environmental Certification

• Grant number: 15/17450-4
• Support Opportunities: Regular Research Grants - Publications - Scientific article
• Start date: September 01, 2015
• End date: February 29, 2016
• Field of knowledge: Engineering - Electrical Engineering - Electrical, Magnetic and Electronic Measurements, Instrumentation
• Principal Investigator: Alexandre de Assis Mota
• Grantee: Alexandre de Assis Mota
• Host Institution: Centro de Ciências Exatas, Ambientais e de Tecnologias. Pontifícia Universidade Católica de Campinas (PUC-CAMP). Campinas , SP, Brazil

Abstract

Nowadays, buildings environmental certifications encourage the implementation of initiatives aiming the increase of energy efficiency in buildings. In these certification systems, increased energy efficiency arising from such initiatives must be demonstrated. Thus, a challenge to be faced is how to check the increase in energy efficiency related to each of the employed initiatives without considerable building retrofit. In this context, this work presents a non-destructive method for electric current sensing to assess implemented initiatives to increase energy efficiency in buildings with environmental certification. This method proposes the use of a sensor that can be installed directly in the low voltage electrical circuit conductors that are power feeding the initiative under evaluation, without the need for reforms that result in significant costs, repair and maintenance. The proposed sensor consists of three elements: an air-core transformer current sensor, an amplifying/filtering stage and a microprocessor. A prototype of the proposed sensor was developed and tests were performed to validate this sensor. Based on laboratory tests, it was possible to characterize the proposed current sensor with respect to the number of turns and cross-sectional area of the primary and secondary coils. Furthermore, using the Least Squares Method, it was possible to determine the efficiency of the air core transformer current sensor (the best efficiency found, considering different test conditions, was 2%), which leads to a linear output response. (AU)