19-10-2010, 03:22 PM
[attachment=6583]
Power Factor Correction
W. Mack Grady
The University of Texas at Austin
Austin, Texas 78712
Robert J. Gilleskie
San Diego Gas & Electric
San Diego, California 92123
Abstract
We are all familiar with power factor, but are we using it to its true potential? In this paper we
investigate the effect of harmonics on power factor and show through examples why it is
http://citeseerx.ist.psu.edu/viewdoc/dow...1&type=pdf
important to use true power factor, rather than the conventional 50/60 Hz displacement power
factor, when describing nonlinear loads.
Introduction
Voltage and current harmonics produced by nonlinear loads increase power losses and, therefore,
have a negative impact on electric utility distribution systems and components. While the exact
relationship between harmonics and losses is very complex and difficult to generalize, the wellestablished
concept of power factor does provide some measure of the relationship, and it is
useful when comparing the relative impacts of nonlinear loads–providing that harmonics are
incorporated into the power factor definition.
Power Factor in Sinusoidal Situations
The concept of power factor originated from the need to quantify how efficiently a load utilizes
the current that it draws from an AC power system. Consider, for example, the ideal sinusoidal
situation shown in Figure
Power Factor Correction
W. Mack Grady
The University of Texas at Austin
Austin, Texas 78712
Robert J. Gilleskie
San Diego Gas & Electric
San Diego, California 92123
Abstract
We are all familiar with power factor, but are we using it to its true potential? In this paper we
investigate the effect of harmonics on power factor and show through examples why it is
http://citeseerx.ist.psu.edu/viewdoc/dow...1&type=pdf
important to use true power factor, rather than the conventional 50/60 Hz displacement power
factor, when describing nonlinear loads.
Introduction
Voltage and current harmonics produced by nonlinear loads increase power losses and, therefore,
have a negative impact on electric utility distribution systems and components. While the exact
relationship between harmonics and losses is very complex and difficult to generalize, the wellestablished
concept of power factor does provide some measure of the relationship, and it is
useful when comparing the relative impacts of nonlinear loads–providing that harmonics are
incorporated into the power factor definition.
Power Factor in Sinusoidal Situations
The concept of power factor originated from the need to quantify how efficiently a load utilizes
the current that it draws from an AC power system. Consider, for example, the ideal sinusoidal
situation shown in Figure
