This project
provides continuous power factor correction without manual capacitive bank
loading. A PFC controller (FIG. 5)
provides power factor correction and peak current limiting for a switch-mode
power converter of any topology (buck, boost or buck-boost), without having to
directly sense inductor current. The PFC control technique involves using a
piecewise-polynomial analog computer (AC) to compute power transistor on-times
in accordance with separate polynomial transfer functions for power-factor
control and peak-current-linking using as inputs current representations of
line input voltage (VLN), load output voltage (VLD), and long-term current
demand (VCD). A conduction cycle is initiated by sensing when the rate of
change in the inductor current reaches zero using an auxiliary winding on the
current storage inductor (Wzd), and terminated after the computed on-time to implement
either power-factor control or peak-current-limiting.
The
Reactive Power charge on your electricity bill is directly targeted against
those companies who do not demonstrate clear energy efficiency use. You will
find this charge itemized on electricity bill. Reactive power charges can be
made significantly smaller by the introduction of Power Factor Correction
Capacitors which is a widely recognized method of reducing an electrical load
and minimizing wasted energy, improving the efficiency of a plant and reducing
the electricity bill. It is not always
necessary to reach a power factor of 1. A cost effective solution can be
achieved by increasing your power factor to greater than 0.95
This
project uses regulated 5V, 750mA power supply. 7805 three terminal voltage
regulator is used for voltage regulation. Bridge type full wave rectifier is
used to rectify the ac out put of secondary of 230/12V step down transformer.
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