Power quality: a utility and industry perspective

The widespread use of electronics in everything from equipment in the home to the control of huge and costly industrial processes has raised the awareness of power quality, issues and concerns over the last few years. The definition of power quality or more specifically, a power quality disturbance, is generally accepted as any change in the power (voltage, current, or frequency) that interferes with normal operation of electrical equipment. It is the susceptibility of the end-use equipment that defines the necessary level of power quality. The intent of this paper is to present information on power quality issues as they affect end-use equipment. The goal of industrial customers is, of course, to stay competitive in the production of their particular product or service. One effective way of accomplishing this is to reduce downtime and thus production loss by limiting the effects of power disturbances. The goal of electric utilities is to maintain a healthy and effective relationship with customers while also promoting the use of electrical energy. It is essential that industrial customers and the utility work together to provide solutions to power quality problems. This paper defines power disturbances in industry accepted terms, examine the sources and effects of these disturbances (for both the utility and the industry), and explore economical solutions based on the compatibility of the equipment and the electrical environment.