Asian American Pacific Islander Month DDSD 2024.pptx
2.. compensación reactiva
1. CARGAS INDUSTRIALES - COMPENSACION REACTIVA ING. HUBER MURILLO
Expositor : Huber Murillo M.
2. TIPOS DE CARGAS
Three categories of loads
RESISTIVES
INDUCTIVES
CAPACITIVES
Ohms Ω
Henry Hy
Farad F
R
L
C
CARGAS INDUSTRIALES - COMPENSACION REACTIVA ING. HUBER MURILLO
5. OHMIC LOAD.
RESISTIVE
IR
VAC R
-400
-300
-200
-100
0
100
200
300
400
0
45
90
135
180
225
270
315
360
405
450
495
540
VAC
IR
CARGAS INDUSTRIALES - COMPENSACION REACTIVA ING. HUBER MURILLO
VAC
IR
ω
6. INDUCTIVE LOAD.
INDUCTIVE
VAC L
-400
-300
-200
-100
0
100
200
300
400
0
45
90
135
180
225
270
315
360
405
450
495
540
VAC
CARGAS INDUSTRIALES - COMPENSACION REACTIVA ING. HUBER MURILLO
Corriente IL = U / ωL Amper.
Potencia P = U² / ωL var or kvar
7. INDUCTIVE LOAD.
INDUCTIVE
IL
VAC L
-400
-300
-200
-100
0
100
200
300
400
0
45
90
135
180
225
270
315
360
405
450
495
540
VAC
IL
CARGAS INDUSTRIALES - COMPENSACION REACTIVA ING. HUBER MURILLO
VAC
IL
ω
90°
8. CAPACITIVE LOAD.
CAPACITIVE
VAC C
-400
-300
-200
-100
0
100
200
300
400
0
45
90
135
180
225
270
315
360
405
450
495
540
VAC
CARGAS INDUSTRIALES - COMPENSACION REACTIVA ING. HUBER MURILLO
Corriente Ic = ω C U Amper.
Potencia P = ω C U² var or kvar
9. CAPACITIVE LOAD.
CAPACITIVE
IC
VAC C
-400
-300
-200
-100
0
100
200
300
400
0
45
90
135
180
225
270
315
360
405
450
495
540
VAC
IC
CARGAS INDUSTRIALES - COMPENSACION REACTIVA ING. HUBER MURILLO
VAC
IC
ω90°
10. MIXED LOADS.
Main industrial loads
I
V L
VR
VL
R
The majority of industrial
loadscan be regarded as
comprising resistor and
inductor in series.
V : supply voltage
VR: resistance voltage drop
VL: inductance voltage drop
I : total supply current
CARGAS INDUSTRIALES - COMPENSACION REACTIVA ING. HUBER MURILLO
11. Main industrial loads
I
V L
VR
VL
R
VR
VL
90°
ω
I
V
φ
"I" lags "V" by some angle φ
CARGAS INDUSTRIALES - COMPENSACION REACTIVA ING. HUBER MURILLO
MIXED LOADS.
12. Main industrial loads
φ
CARGAS INDUSTRIALES - COMPENSACION REACTIVA ING. HUBER MURILLO
MIXED LOADS.
13. CAPACITOR CONNECTION
I
L
R
V
IRL
IRL : current through the load
IC : current through the
capacitor
I : total current drawn from
supply
C
IC
CARGAS INDUSTRIALES - COMPENSACION REACTIVA ING. HUBER MURILLO
MIXED LOADS.
14. CAPACITOR CONNECTION
I
V L
R
IC ω
V
IRL
C
IRL
IC
I
ϕ1
ϕ2
ϕ1 ϕ2
ϕ cos ϕ I
CARGAS INDUSTRIALES - COMPENSACION REACTIVA ING. HUBER MURILLO
MIXED LOADS.
15. k
W
- Active power (kW)
performs the work (useful power)
kVA
- Apparent power (kVA)
total power consumed
kv
ar
- Reactive power (kvar)
sustains electromagnetic field (non useful power)
CARGAS INDUSTRIALES - COMPENSACION REACTIVA ING. HUBER MURILLO
REACTIVE POWER COMPENSATION.
16. BASIC CONCEPTS.
kVA
Apparent power
φ
Active or useful power
kW
Reactive
power
kvar
kvar
Power factor
cos φ = kW / kVA
CARGAS INDUSTRIALES - COMPENSACION REACTIVA ING. HUBER MURILLO
HOW CAN WE IMPROVE THE PF
CORRECTION AND THUS REDUCE THE
CONSUMED POWER?
17. kW
Kvar2
The capacitor connected in parallel will
draw kvar in the same way than the
load but in phase opposition (leading)
kVA
kvar1
CARGAS INDUSTRIALES - COMPENSACION REACTIVA ING. HUBER MURILLO
BASIC CONCEPTS.
18. CARGAS INDUSTRIALES - COMPENSACION REACTIVA ING. HUBER MURILLO
BASIC CONCEPTS.
φ1
kW
kvar
kVA1
φ2
kVA2
kvar2
kvar1
31. kVA output reduced
cos φ initial
% kVA recovered
0.75
CARGAS INDUSTRIALES - COMPENSACION REACTIVA ING. HUBER MURILLO
32. Voltage drop in transformer
5.1
Voltage drop
cos φ
0.6
Low losses
CARGAS INDUSTRIALES - COMPENSACION REACTIVA ING. HUBER MURILLO
Normal losses
VOLTGE DROP
Cos ? = 0.6 * 5.1%
Cos ? = 0.6306
Cos φ = 0.6306
φ = 50.906
33. Typical PF encountered in industry
CARGAS INDUSTRIALES - COMPENSACION REACTIVA ING. HUBER MURILLO
34. Energy saving calculation.
400 kVA
400 V
P=80 kW
cos φ = 0.75
P=170 kW
cos φ = 0.75
1 cable
70 mm²
20 m
2 cables
70 mm²
100 m
A B
CARGAS INDUSTRIALES - COMPENSACION REACTIVA ING. HUBER MURILLO
35. Energy saving calculation.
Consumer's electricity bill:
• Monthly kWh consumed = 70125
• Monthly kvarh consumed = 63081
• Assuming an activity of :
340 days/year
15 hours/day
• Average kW = 70125/425 = 165 (66% of the full load)
• Average kvar = 63081/425 = 148
• Average kVA = √165² + 148² = 222
• Average P.F. = kW/ √kW² + kvar² = 0.744
CARGAS INDUSTRIALES - COMPENSACION REACTIVA ING. HUBER MURILLO
36. Energy saving calculation.
Min P.F. value to avoid penalty : 0.93
capacitor required = kW (tgφ1 - tgφ2)
=165 (0.898 - 0.395) = 83kvar
(in practice cap. size is increased by 5 to 10% to ensure a
P.F.> 0.93)
New situation
kW = 165 (unchanged)
kvar = 148 - 83 = 65 ()
kVA = √165² + 65² = 177 () (222 previously)
Monthly demand (kVA) is reduced by 20%
CARGAS INDUSTRIALES - COMPENSACION REACTIVA ING. HUBER MURILLO
37. Cable losses
Cos φ = 0.75
Workshop A :
I = P*0.66/ √3 V cos φ
= 80000 * 0.66/ √3 400 0.75 = 102A
Cable losses : P = 3 RI²L (R= ρ1/S)
= 3 * 246.10-6
Ω/m * (102)² * 20 =154W
5100 h/year P = 785kWh
Workshop B :
I = 170000 * 0.66/√3 400 0.75 = 216A
Cable losses : P = 2 (3RI²L)
= 2 * 3 * 246.10-6
* (216/2)² * 100 = 1722W
5100h/year P = 8782 kWh
CARGAS INDUSTRIALES - COMPENSACION REACTIVA ING. HUBER MURILLO
39. Transformer losses
Before correction:
Total losses = 1000 + 5000 [(80+170) 0.66]² / (0.75 * 400)= 2513W
Total losses/year = 2513X5100 = 12814kWh
Total kWh = 785 + 8782 + 12814 = 22381
After correction:
Total losses = 1000 + 5000 [(80+170) 0.66]²/ (0.93 * 400) = 1984W
Total losses/year = 10118kWh
Total kWh/year = 510+5697+10118 = 16325
kWh reduction/year = 22381 - 16325 = 6056kWh
27% reduction
CARGAS INDUSTRIALES - COMPENSACION REACTIVA ING. HUBER MURILLO
40. POWER FACTOR CORRECTION
The main reason for installing power capacitors is to
reduce reactive power costs and avoid the penalties.
Typical pay back period is less than 1-2 years.
Sometimes as little as a few months.
CARGAS INDUSTRIALES - COMPENSACION REACTIVA ING. HUBER MURILLO
TYPICAL INSTALLATION
• Individual compensation of large motors (>50kW ≈ 70hp)
• Fixed compensation of transformers (+/-10 % of transformer rating)
• Automatic capacitor bank to compensate varying load
41. Locating capacitors on your system
Capacitors may be installed at various locations on your
electrical system.
1 : Capacitors on the incoming plant service
2 : Capacitors on the main bus
3 : Capacitors on the bus for various feeders
4 : Capacitors a the individual load point
Capacitor location
1 2 &3 4
Technical approach Best
Flexibility Least Less Best
Savings Least less Max.
Cost per kvar Least Lower Highest
CARGAS INDUSTRIALES - COMPENSACION REACTIVA ING. HUBER MURILLO
42. TRANSFORMER COMPENSATION
- Increased useful capacity
- Reduced losses
- Reduced voltage drop
Degree of compensation :
1. "Rule of thumb" : +/- 10 % of transformer's nominal rating.
2. Calculation based on the individual transformer and its load pattern.
Note : check for resonance between transformer and capacitor.
CARGAS INDUSTRIALES - COMPENSACION REACTIVA ING. HUBER MURILLO
43. Individual transformer compensation
The resonant frequency can be calculated from the following
formula :
f fp
Psc
Pc
=
f = resonant frequency
fp = power frequency
Psc = short circuit power of the transformer (kVA)
Pc = power of the capacitor (kVAR)
If the frequency obtained is too close to that of a harmonic, the
value of the capacitor rating should be modified.
Most common harmonic frequencies, 3rd, 5th, 7th, etc...
CARGAS INDUSTRIALES - COMPENSACION REACTIVA ING. HUBER MURILLO
44. MOTOR COMPENSATION
CARGAS INDUSTRIALES - COMPENSACION REACTIVA ING. HUBER MURILLO
Methods for determining capacitor
rating for motor compensation
1.- Rule of thumb Qc = 40% of motor KW .
rating.
2.- Use of table the speed and motor power .
into acount
3.- Calculation based on exact individual
. motor charasteristics.
45. AUTOMATIC BANK COMPENSATION
Advantages of automatic capacitor banks :
- Regulation of cos φ.
- Better utilisation of the capacitor compared to individual compensation.
- Eliminates the possibility of overcompensation.
CARGAS INDUSTRIALES - COMPENSACION REACTIVA ING. HUBER MURILLO
46. AUTOMATIC BANK COMPENSATION
Points to consider for automatic banks
• Choice of regulator characteristics (c/k and tolerance) and step size to
avoid hunting.
• Correlation between minimum interval between switching and discharge
device of capacitor to avoid energising a charged capacitor.
• Disconnecting of all steps in case of a mains outage.
• Insensitivity to harmonics.
• Possibility to extend existing banks without changes in the control
equipment.
CARGAS INDUSTRIALES - COMPENSACION REACTIVA ING. HUBER MURILLO
47. LVCP
THE NEW CHOICE FOR POWER
FACTOR CORRECTION
BANCO DE CONDENSADORES ING. HUBER
Compact
Modular
Safe
Reliable
48. Compact Small dimensions
210 mm
200 mm78 mm
Compact High
power density
20 kvar
@ 400/415 V
BANCO DE CONDENSADORES ING. HUBER
49. Modular
Terminals sized for
common cable shoes
Built-in safety discharge
resistors (<75V in 3 min.)
Enclosure with double
casing insulation
BANCO DE CONDENSADORES ING. HUBER
51. Modular
Easy and quick assembly
of capacitor modules
BANCO DE CONDENSADORES ING. HUBER
DIN rail fixation
52. Examples of LVCP module assembly
30 kvar = 15 kvar + 15 kvar
35 kvar = 20 kvar + 15 kvar
40 kvar = 20 kvar + 20 kvar
400V/50Hz
BANCO DE CONDENSADORES ING. HUBER