The importance of Power Quality Monitoring

Power Quality Analyzers are used to diagnose problems that may affect the quality of the power grid. For instance, when there are significant changes in the voltage and current waveforms, Power Quality Analyzers detect and record the main problems characteristics that could determine, by a further analysis, the origin of those problems. The characterization of problems is done according to certain standards, for example the standard NP EN 50160 which defines the voltage characteristics of the electricity supplied by public distribution systems.

Power Quality Analyzers can be used for energy consumption profile optimization, for preventive maintenance and also for choosing the best equipment to mitigate the problems related with the Power Quality.

While there is many Power Quality Analyzers available in the market, the most sophisticated ones are still expensive and, due to their complexity, the interface with users isn’t as friendly as it should be. There are many manufacturers who have solutions for Power Quality Analyzing, namely Fluke, Schneider, Dranetz, etc.

Power Quality Analyzers developed by GEPE

In the last decade, the Group of Energy and Power Electronics has developed low-cost Power Quality Analyzers. The first prototype was developed in 2003 and was based on a common personal computer with a data acquisition board connected to the PCI bus. The whole software for processing data was developed using LabView, as well as the graphical user interface. This prototype wasn’t yet a portable solution due to its dimensions and weight.

First prototype of a Power Quality Analyzer developed by GEPE.

The following prototype was developed in 2008 in scope of project SINUS. In comparison with the previous prototype developed, the overall dimensions and power consumption were improved, with the objective to include all parts in a portable case. It was also developed a variant to embed in a Shunt Active Power Filter. Relative to software, the entire architecture was sustained and some of functionalities were improved.

Second generation of Power Quality Analyzers developed by GEPE: (left) Portable variant; (right) Fixed variant to embed in Shunt Active Power Filters.

Actually, GEPE is developing a new prototype of a low-cost and small-sized Power Quality Analyzer. This version is constituted only free software, excluding the necessity of acquiring software licenses. In this variant, the conditioning and acquisition circuits were developed from the scratch. The interface between the user and the Power Quality Analyzer is done through touch-screen 10’’ LCD.

Power Quality Analyzer in development stage.