Low-cost digital system for power quality monitoring

Abstract

This paper describes the development of a low cost digital system used for power quality monitoring and power management. The system uses voltage and current Hall sensors, a standard data acquisition board, and has its processing system based in LabVIEW™, running on a regular PC. The system acquires data continuously, and storage in files the events that result from the anomalies detected in the monitored power system. Several parameters related to power quality can be analysed through 6 different applications: “Scope and THD”, “Strip Chart”, “Wave Shape”, “Sags and Swells”, “Classical Values” and “p-q Theory Values”. The acquired information can be visualized in tables and/or in charts. It is also possible to generate reports in HTML format. In this format, the reports can be sent directly to a printer, can be embedded in other software applications, or can be accessed through the Internet, using a web browser. It is also shown the potential of the developed system, namely the advantages of virtual instrumentation, regarding to flexibility, cost and performance in the scope of power quality monitoring and power management (after acquisition, processing and analysing of the information, data and warnings can be sent through Internet or wireless technology).