A low-cost power quality meter for utility and consumer assessments

Power quality has become a major concern, in particular, to the domestic consumers because the reliability, efficiency and liability of their devices very much rely on the quality of the electric supply. However, up to now, there is no cost-effective instrument for power quality measurement. It is partially due to the lacking of a world-wide accepted indicator, power performance index (PPI) in the authors' case, and partially due to the conventionally high cost of power quality measurement equipment. In this paper, a good performance index, PPI, is proposed for the consideration by the power industry. Individual components arriving at the PPI are defined and the method of calculation is explained in detail. Such PPI will also be useful to assess the supply quality of independent power providers, especially for deregulation purposes. All algorithms have been implemented on a cost-effective power quality meter (PQM) while both hardware and software designs are described in this paper.