CONSIDERATIONS FOR A WIDE-AREA POWER QUALITY MONITORING SYSTEM THE NEED FOR IMPROVED AWARENESS

ABSTRACT Power quality monitoring has evolved from device-specific analysis of an event to system-wide benchmarking and reporting. Whether THE NEED FOR IMPROVED AWARENESS While the 2003 blackouts in Europe and America brought media attention to power quality and reliability, the need for increased awareness of the state of the grid has been growing for much longer and with much less dramatic symptoms. As new distorting loads are added, system total harmonic distortion (THD) increases, degrading the life of both industrial and consumer hardware and approaching fuse limits. Rapid voltage changes (Flicker) at the edge of human perception lead to eye strain and reduced worker productivity. And an immediate cost is borne by the economy, where the U.S. Department of Energy estimates that "power outages and power quality disturbances cost the economy from $25 to $180 billion annually. There are also operational problems in maintaining voltage levels." If this economic loss is to be reduced, we must first understand the state of the grid today. To gather the necessary intelligence, a Wide-Area Power Quality analysis (WAPQ) system uses power quality monitors distributed throughout the grid to monitor, record and in some cases alarm on power quality phenomena. While this level of monitoring is useful for a minute-to-minute operational view, system software is required to deal with the volume of data and convert it to actionable information. In addition to the information obtained on overall grid status, a WAPQ system improves the ability of power quality departments to respond to customer complaints. Portable or temporarily installed power quality monitors have been used for this analysis in the past. When the problem observed by the customer was caused by a quasistationary and persistent condition, such as harmonics, or by periodic events, such as line-switching or motor start-up, installing a portable PQ monitor and evaluating its data would provide the necessary information to the customer. This approach, however, is not effective for spurious events which may not repeat after the installation of the portable device. Without information on these events, it is not possible to evaluate the source of a problem or the potential damage such an event may have caused to equipment. WAPQ systems can be effectively used to address one or more of three main needs: Standards compliance, System reliability improvements, and Customer satisfaction