Scientific Research Journal (SCIRJ), Volume III, Issue IX, September 2015
ISSN 2201-2796
1
Evaluation of Percentage Wasted Power in Electrical
Loads with Constructed Power Factor Correction
Equipment
Afolabi O.M
Department of Physics & Electronics
Adekunle Ajasin University
Akungba Akoko Nigeria
Abstract- Fixed capacitive low power factor correction
measurements was done to calculate percentage wasted power.
The output of the nine operational amplifier voltage comparator
controlled stabilizer was connected to a fixed CBB61; 450V 2uF
AC run capacitor unto which each load was connected and
computation of apparent power, power factor and percentage
wasted power were made. It was found that very high percentage
of required real power was wasted when power factor was
uncorrected in electrical appliances studied. 52% of power was
wasted in three laptops combination that reduced to 8.6% after
CPF compare to 36.5% when 3 loads comprising of a laptop,
printer and electric fan was used that was reduced to 3.3%.
Minimum power was wasted in Philips Elance 3100, Electric iron
with 32.3% when the power factor was uncorrected and 3.2%
when power factor was corrected.
IndexTerms—Electrical Power, loads,
Percentage Wasted Power, Required.
Power factor,
I. INTRODUCTION
Electrical distribution is in the form of a low frequency
high voltage and low current to save cost incurred in
conducting and insulating materials; to reduced overheating of
cables and for ease of transformation from high to low voltage
required at the consumer points. Alternating current systems
supply two forms of energy: Real energy measured in kilowatt
hours (kWh) which is converted into mechanical work, heat,
light, etc and Reactive energy needed to generate magnetic
fields by inductive circuits (transformers, motors, cables,
refrigerators, inverters
discharge lamps (with magnetic
ballasts) etc.), Schneider Electric, 2008, Sugawara et al., 2007.
In industries, Low power factor results when inactive motors
are operated at less than full load. This often occurs in cycle
processes occurring in circular saws, mills, conveyors,
compressors, Grinders and punch presses, www.eaton.com,
2014. Low power factor is easily corrected by adding, in
parallel to load, a capacitive reactance that acts in opposite
sign as the load’s inductive reactance. Low power factor input
in distribution systems causes power losses in transmission and
distribution systems by heating the conductors, ON
Semiconductor 2007. The combination of inductive reactance
in transmission and distribution systems and that of consumer
loads produces the worst possible conditions of low power
factor. Power factor correction capacitors reduce the
(inductive) reactive current in upstream conductors, thereby
reducing or eliminating voltage drops (electroschematics,
2015; fairchildsemi, 2015).
By improving the power factor of a load supplied from a
transformer,
(a) the current or power through the transformer will be
reduced, thereby allowing more load to be added (it is
cheaper to improve the power of transformer than to
replace it with a bigger one),
(b) the excess bill or penalties for excessive consumption
of reactive power is reduced because the apparent
power kVA demand, on which standing charges are
usually based is reduced,
(c ) the size of the cables supplying the local distribution
boards is reduced and the cables have additional capacity for
possible load increases,
(c) heat losses in cables, transformers and loads will be
reduced and they will have longer lifespan.
From the power triangle (Fig.1) the bigger the reactive
power component, the higher is the power factor of the circuit
kVAR = kVAsinθ……………………………….…1
but
kW
kVA =
………………………………….…………2
Cos θ
kWSinθ
kVA =
= kWtanθ……………………………….3
Cos θ
The lower the power factor (cosθ ) the more the apparent
power(kVA) or electrical bill.
kVA2 = kW2 + kVAR2………….…………………4
For an electrical appliance with the power factor corrected,
the apparent power is reduced since real power (kW) is fixed
then the reactive power is reduced hence apparent power is
affected by the reactive power (see equation 4).
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© 2015, Scientific Research Journal
Scientific Research Journal (SCIRJ), Volume III, Issue IX, September 2015
ISSN 2201-2796
2
kW
𝜃2
kVAR2
𝜃1
kVA2
kVA1
kVAR1
Fig. 1: Increase in kVA2,kVAR2 and 𝛉𝟐 due to induction sources
A constructed stabilized power factor corrected and current
voltage measuring equipment with ability to measure input
voltage and output voltage and current (see Fig. 2) was used for
2uF
400V
output port
VO
GND
VI
R9
2
15k
R11
C4
100uF
U1:A
10k
V
AC Volts
3
8
AMMETER
D4
+88.8
RV1
3
1
2
Q1
R5
BD139
10k
R1
4
96%
TRAN-2P2S
D1
10k
LM393
50k
7
Q2
R6
BD139
10k
R2
4
37%
6
10k
LM393
50k
D2
QUAZ-SH-105D
1
2
50%
RL3
1nF
3
BD139
10k
10k
4
10k
Q7
5
7
10k
6
Q4
R8
BD139
4
R4
L1
10k
LM393
D5
3
1
D6
5
BD139
7
50%
6
RL2
L2
1nF
Q6
R18
BD139
10k
R13
10k
4
10k
D8
LM393
50k
DIODE
8
U5:B
RV7
5
7
6
Q8
R19
BD139
10k
R16
4
50k
C6
DIODE
8
RV6
Q9
R10
4
10k
U4:B
1
LM393
BD139
R12
LM393
50k
50%
10k
1mH
10k
8
R20
QUAZ-SH-105D
Q5
R17
4
37%
2
U6:A
2
RL1
1nF
8
RV5
QUAZ-SH-105D
C5
DIODE
U4:A
3
1nF
10k
50k
RL5
C3
DIODE
U2:B
RV4
50%
4
D3
LM393
50k
BD139
R14
LM393
R3
8
R15
2
Q3
R7
8
3
1
51%
C7
L3
1nF
8
RV3
DIODE
C2
DIODE
U2:A
D7
1nF
8
5
U5:A
C1
DIODE
U1:B
RV2
70%
VOLTMETER
+88.8
AC Amps
+88.8
AC Amps
7812
TR1
1k
+88.8
AC Volts
U3
1
DIODE
ADE
AMMETER
II. MATERIAL AND METHOD
VOLTMETER
the data collection in eleven electrical loads. The output of the
stabilizer is connected to a CBB61; 450V 2uF AC run
capacitor unto which each load was connected and
computation of apparent power, power factor and percentage
wasted power with and without the correction was done.
LM393
10k
Fig. 2 Stabilized power factor measuring circuit
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© 2015, Scientific Research Journal
C8
RL4
1nF
QUAZ-SH-105D
L4
Scientific Research Journal (SCIRJ), Volume III, Issue IX, September 2015
ISSN 2201-2796
3
III. RESULT AND DISCUSSION
Tables 1 and 2 show the measurement of voltage and current for corrected power factor (CPF) and uncorrected power factor
(UPF). The voltages and current in uncorrected power factor are higher than when they are corrected; this resulted in more apparent
power (see Tables 3)
Table 1: Stabilized Output Voltage and Load Current without Power Factor Correction
S/N
LOAD
INPUT
VOLTAGE (V)
STABILIZED
OUTPUT VOLTAGE
(V)
250.0
LOAD
CURRENT
(A)
4.80
1
Sharp air conditioner
230
2
Haier thermocool refrigerator HRF250DX
230.0
245.0
2.00
3
Hand hair dryer
230.0
245.0
5.00
4
Electric iron
225.0
245.0
10.80
5
Electric clipper
230.0
240.0
0.06
6
Electric stove
230.0
240.0
5.80
7
Electric fan 18” century product
230.0
240.0
0.60
8
Hp pavilion DV600 and Acer V5series
laptops
230.0
240.0
0.80
9
Hp pavilion DV600, Hp 630 and Acer
laptops
230.0
240.0
1.40
Acer laptop V5series, hp printer P1102
and Century fan 18”
230.0
245.0
4.40
230.0
240.0
6.00
10
11
Battery charger
Table 2: Stabilized Output Voltage and Load Current with Power Factor Correction.
S/N
LOAD
1
Sharp air conditioner
2
Haier
thermocool
HRF250DX
INPUT
VOLTAGE (V)
refrigerator
STABILIZED
OUTPUT
VOLTAGE(V)
LOAD
CURRENT
(A)
230.0
240.0
4.20
230.0
240.0
1.60
3
Hand hair dryer
230.0
240.0
4.00
4
Electric iron
230.0
240.0
8.60
5
Electric clipper
230.0
240.0
0.05
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© 2015, Scientific Research Journal
Scientific Research Journal (SCIRJ), Volume III, Issue IX, September 2015
ISSN 2201-2796
6
Electric stove
230.0
240.0
4.40
7
Electric Century fan 18”
230.0
240.0
0.50
230.0
240.0
0.60
230.0
240.0
1.00
230.0
240.0
3.40
230.0
240.0
4.40
8
9
10
4
Hp pavilion DV600 and Acer
V5series laptops
Hp pavilion DV600, Hp 630 and
Acer laptops
Acer laptop V5series, hp printer
P1102 and Century fan 18”
11
Battery charger
Table 3: Loads’ Real Power and Computed Apparent Power for CPF and UPF
S/N
STABILIZED
AND
CORRECTED
POWER
FACTOR
APPARENT POWER
(VA)
1008.0
STABILIZED AND
UNCORRECTED POWER
FACTOR
APPARENT POWER
(VA)
1200.0
Sharp air conditioner
900
2
Haier thermocool refrigerator HRF250DX
360
384.0
490.0
3
Hand hair dryer (Bestside RCE 2300)
900
960.0
1225.0
4
Electric iron (Philips Elance 3100)
2000
2064.0
2646.0
5
Electric clipper (Kinsclip NC-222)
10
12.0
14.40
6
Electric stove
1000
1056.0
1392.0
7
Electric fan 18” century product
100
120.0
144.0
131
144.0
192.0
221
240.0
336.0
790
816.0
1078.0
1000
1056.0
1440.0
9
11
REAL
POWER
(W)
1
8
10
LOAD
Hp pavilion DV600 and Acer V5series
laptops
Hp pavilion DV600, Hp 630 and Acer laptops
Acer laptop V5series, hp printer P1102 and
Century fan 18”
Battery charger
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© 2015, Scientific Research Journal
Scientific Research Journal (SCIRJ), Volume III, Issue IX, September 2015
ISSN 2201-2796
5
Table 4: Percentage Wasted Power for Corrected and Uncorrected Power factor
S/N
LOAD
WAS
TED
POWER
WITH
NO PFC
(VA)
WAS
TED
POWER
WITH
PFC
(VA)
PERCENTA
GE WASTED
POWER
WITH NO
PFC (%)
PERCENTA
GE
WASTED
POWER
WITH PFC
(%)
1
Sharp air
conditioner
300
108
33.3
12
2
Haier
thermocool
refrigerator
HRF250DX
Hand
hair
dryer
(Bestside
RCE 2300)
130
24
36.1
6.7
325
60
36.1
6.7
4
Electric
iron (Philips
Elance
3100)
646
64
32.3
3.2
5
Electric
clipper
(Kinsclip
NC-222)
4.4
2
44
20
6
Electric
stove
392
56
39.2
5.6
7
Electric
fan
18”
century
product
Hp
pavilion
DV600 and
Acer
V5series
laptops
Hp
pavilion
DV600, Hp
630
and
Acer laptops
44
20
44
20
61
13
46.6
9.9
115
19
52.0
8.6
3
8
9
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© 2015, Scientific Research Journal
Scientific Research Journal (SCIRJ), Volume III, Issue IX, September 2015
ISSN 2201-2796
6
10
Acer
laptop
V5series, hp
printer
P1102 and
Century fan
18”
288
26
36.5
3.3
11
Battery
charger
440
56
44
5.6
Table 4 and Figure 3 show that very high percentage of
required real power is wasted when power factor is
uncorrected. 52% of power is wasted in three laptops
combination that reduced to 8.6% after CPF compare to 36.5%
when 3 loads comprising of a laptop, printer and electric fan
was used that was reduced to 3.3% and 46.6% that reduced to
9.9% after CPF when two laptops, Hp pavilion DV600 and
Acer V5series laptops were used. Minimum power was wasted
in Philips Elance 3100, Electric iron with 32.3% when the
power factor was uncorrected and 3.2% when power factor was
corrected. The highest wasted power after correction of power
factor is in Century 18” Electric fan and Kinsclip NC-222
Electric clipper with similar 20% wasted power and
corresponding 44% uncorrected wasted power.
60
50
40
PERCENTAGE WASTED POWER
WITH NO PFC (%)
30
PERCENTAGE WASTED POWER
WITH PFC (%)
20
10
0
1
2
3
4
5
6
7
8
9
10
11
Fig. 3: Percentage wasted power in electrical loads
IV. CONCLUSION
REFERENCES
A stabilized power factor corrected and current voltage
measuring equipment useful to evaluate power factor was
designed and constructed. It was found that more voltage and
current were consumed when power factor was not corrected
resulting in more percentage of real power being wasted. The
corrected power factor reduced the apparent power needed for
the loads to operate this will reduce electrical power wasted as
heat with lower electrical bill, reactive power penalties and a
longer lasting electrical distribution system and consumer
appliances.
[1] ON Semiconductor, 2007. Power Factor Correction Handbook
(PDF).
[2] Schneider Electric - Electrical installation guide 2008 Power
factor correction and
harmonic filtering.
[3] Sugawara, I.; Suzuki, Y.; Takeuchi, A.; Teshima, T. (19–23 Oct
1997),
"Experimental studies on active and passive PFC
circuits", INTELEC 97, 19th International Telecommunications
Energy
Conference,
pp.
571–78,
doi:10.1109/INTLEC.1997.646051.
[4] www.eaton.com,2014. Power factor correction: a guide for the
plant engineer
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© 2015, Scientific Research Journal
Scientific Research Journal (SCIRJ), Volume III, Issue IX, September 2015
ISSN 2201-2796
Technical Data SA02607001E.
[5] www.electroschematics.com/5726/power-factor-correction/
accessed August 2015.
7
[6] www.fairchildsemi.com, 2004. Application Note 42047 Power
Factor Correction (PFC) Basics
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