Power factor correction techniques for Non linear loads
Modern electronic equipment does not represent a completely passive load
to the AC mains or power line. Historically, loads have been fairly benign,
having either resistive characteristics (light bulbs) or input currents that are
sinusoidal but phase-shifted (AC motors). Most electronic systems now use
one or more switch mode power converters that will tend to draw current from
the power line in a non-sinusoidal fashion. This input current characteristic
results in current and possibly voltage distortions that can create problems
with other equipment connected to the power line and degrade the capability
of the mains. These problems have led to the creation of design standards
for the purpose of limiting the allowable harmonic distortion on the power line.
Fortunately, solutions are available for meeting these standards. These
solutions are referred to as Power Factor Correction (PFC) techniques.