Status of distribution reliability and power quality in the United States

Utility companies have always made major efforts to provide reliable power with good characteristics. The term "power quality", however, took on an entirely new meaning about 20 years ago resulting from concerns with sensitive loads such as computers, PLCs, digital clocks and VCRs. In these 20 plus years, no one has successfully been able to come up with a definition of what constitutes good power quality. Power quality, like beauty, seems to be in the eye of the beholder. While there is no agreed upon definition for good power quality, much work in the areas of harmonics, surges, voltage flicker, interruptions, etc. has taken place. The purpose of this paper is to update the reader on the status of all these areas that comprise the term "power quality". Much has been done in terms of measurement, standardization, surveys, and mitigation that this paper attempts to summarize.