Guidelines for Power Factor Improvement Projects

Abstract

Power factor is an indication of electrical system efficiency. Low power factor, or low system efficiency, may be due to one or more causes, including lightly loaded transformers, oversized electric motors, and harmonic-generating non-linear loads. Knowing the cause of low power factor is essential to developing an effective remedy. If low power factor is caused by harmonic loads, for example, the misapplication of capacitor banks alone could create other, more significant problems. Additionally, the goal of power factor improvement can vary from the simple reduction of utility costs to the complex elimination of harmonic load currents. Regardless of the cause of low power factor or the goal in improving system efficiency, the methodology in defining the solution is similar. This paper discusses the critical issues involved in developing a power factor improvement project. Note: The views expressed in this paper do not necessarily represent the views of the United States of America, the U. S. Department of Justice, or the Federal Bureau of Prisons.