Transcript Power Factor Correction

American Control Technologies,Inc
Power Factor Correction
Technology
1152 West 2400 South Suite ‘C’ Salt Lake City, Utah 84119
Overview
• What Is Power Factor?
• What is Power Factor Correction?
• How Does It Work?
• What Are The Benefits?
• What Makes ACT’S Power Factor Correction Unit Better?
• Actual Results In Clarksville, TN
What Is Power Factor?
Power factor is the ratio between the KW and the KVA drawn by an
electrical load where the KW is the actual load power and the KVA is
the apparent load power. It is a measure of how effectively the
current is being converted into useful work output and more
particularly is a good indicator of the effect of the load current on
the efficiency of the supply system.
When electricity energizes the coils of a motor, a reverse current or reactive
power from the coils is created. This phenomenon is an expression in electrical
physics of Newton’s Third Law of action and reaction. When coiled devices use
electricity to perform useful work, the process also creates reactive electrical
fields that resist the effective working of the active electrical energy. The reactive
power opposes the incoming current. The opposition creates an abnormal
condition in which voltage reaches its maximum charge before current reaches its
maximum flow. Voltage and current are out of phase. By the time the current
overcomes the opposition and finally reaches its maximum flow, the voltage
charge has already begun to dissipate, making the transfer of energy less
effective. This loss of effective energy is called low power factor. This is called a
“lagging power factor” in that the current is lagging behind the voltage. A
capacitor works the opposite from a coil; it causes the current to lead the voltage
causing a “leading power factor”. A motor or coil causes inductive reactance,
capacitors cause capacitive reactance. If the inductive reactance and capacitive
reactance are equal they cancel each other, causing the current and voltage to be
in phase.
The term “phase angle” is from trigonometry. It describes the relationship
of current and voltage, the two parts of working electricity. For current
and voltage to produce maximum power, they must be “in phase” with
each other. The graphs of their waveforms should overlay each other, so
that their waveforms appear simultaneously. Ideally, voltage should reach
its maximum value at the same time that the current reaches its maximum
value. The optimum phase angle is zero degrees.
What Is Power Factor Correction?
Fig. a. This graph depicts a load that is high in inductance. As you can see
current and voltage are not in phase, the current lags the voltage.
Fig. b. This graph depicts a load that is high in capacitance. As you can see
voltage and current are not in phase, the current leads the voltage.
Fig. c. This graph shows inductance and capacitance, for all practical
purposes, equal. As you can see the current and voltage are in phase.
What Are The Benefits?
• Up to 25% savings on power bill
• Equipment will run cooler, longer life, less
maintenance
• Environmentally Friendly
What Makes ACT’S Power Factor
Correction Unit Better?
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When installed, improves power factor, increases KVA capacity and efficiency of
present electrical distribution system
UL 508 listed, complete assembly
NEMA 1 formed steel enclosure, with bottom entry access
Compact, economical design allows for maximum KVAR in a small footprint
Modular design allows for future expansion, match and line
Three phase power capacitors with 25, 50, 100 and 200 KVAR steps, with other
sizes also available
Current limiting type fuses rated at 100kaic, three-phase fault protection
Blown fuse indication
Microprocessor based power factor controller with digital display
Automatically switched capacitors provide more efficient operation and minimizes
load transients
Easy installation and start-up
Actual Results In Clarksville, TN
An 600 Amp ACT power factor correction unit
was installed at the Ringgold Road pump station
in Clarksville, TN. A Fluke meter was installed
across the unit and monitored with a laptop
computer. Two power factor samples were
recorded and documented in an Excel spread
sheet. The results are as follows:
Clarksville PFC_off
1.2
1
0.8
PF1_off
PF 0.6
PF2_off
PF3_off
0.4
0.2
0
1
5
9
13
17
21
25
29
33
37
41
45
49
53
57
61
65
69
73
77
81
85
89
93
97
101 105 109 113 117 121 125
Tim e
This graph shows the power factor with the ACT PFC off. As you can see
the power factor on phase 1 is approximately .83, phase 2 .82, and phase
3 .88.
Clarksville_PFC_on
1.2
1
0.8
PF1_on
PF 0.6
PF2_on
PF3_on
0.4
0.2
0
1
5
9
13
17
21
25
29
33
37
41
45
49
53
57
61
65
69
73
77
81
85
89
93
97 101 105 109 113 117 121 125 129 133 137
Tim e
This graph shows the power factor with the ACT PFC on. As you can see the power
factor on all 3 phases is .98 or better. This equates to a 15 to 20 percent power savings.
For additional information on
our power factor correction
solution, or other products and
solutions offered by ACT for
your water/wastewater facility,
please contact us at:
801-972-1555
801-972-5056 fax
www.americancomptech.com