Mitsubishi Electric 800 Series Instruction Manual page 98

 Equivalent capacity limit
Received power voltage
6.6 kV
22/33 kV
66 kV or more
 Harmonic content (when the fundamental current is considered as 100%)
Not used
Used (AC side)
Three-phase bridge
(capacitor smoothing)
Used (DC side)
Used (AC, DC sides)
Single-phase bridge Not used
(capacitor smoothing,
Used (AC side)
full-wave rectification)
 Calculation of equivalent capacity P0 of harmonic generating equipment
"Equivalent capacity" is the capacity of a 6-pulse converter converted from the capacity of consumer's harmonic generating
equipment and is calculated by the following equation. If the sum of equivalent capacities is higher than the limit (refer to the
list of the equivalent capacity limits), harmonics must be calculated by the equation in next subheading.
P0 = Σ (Ki × Pi) [kVA]
Ki: Conversion factor (Refer to the list of the conversion
factors.)
Pi: Rated capacity of harmonic generating equipment
i: Number indicating the conversion circuit type
*1 Rated capacity: Determined by the capacity of the applied motor and found in the table "Rated capacities and outgoing harmonic currents of
inverter-driven motors". The rated capacity used here is used to calculate the generated harmonic amount and is different from the power supply
capacity required for actual inverter drive.
 Calculation of outgoing harmonic current
Outgoing harmonic current = fundamental wave current (value converted from received power voltage) × operation ratio ×
harmonic content
• Operation ratio: actual load factor × operation time ratio during 30 minutes
• Harmonic content: Refer to the list of the harmonic content.
 Rated capacities and outgoing harmonic currents of inverter-driven motors
Fundamental
wave current (A)
Applicable
motor (kW)
200 V 400 V
0.4 1.61 0.81
0.75 2.74 1.37
1.5 5.50 2.75
2.2 7.93 3.96
3.7 13.0 6.50
5.5 19.1 9.55
7.5 25.6 12.8
 Determining if a countermeasure is required
A countermeasure for harmonics is required if the following condition is satisfied: outgoing harmonic current > maximum value
per 1 kW contract power × contract power.
Reference capacity
50 kVA
300 kVA
2000 kVA
Reactor 5th
65 41
38 14.5
30 13
28 9.1
60 33.5
31.9 8.3
*1
[kVA]
Fundamenta
Outgoing harmonic current converted from 6.6 kV (mA) (No reactor, 100%
l wave
Rated
current
capacity
converted
(kVA)
5th
from 6.6 kV
(mA)
49 0.57 31.85
83 0.97 53.95
167 1.95 108.6
240 2.81 156.0
394 4.61 257.1
579 6.77 376.1
776 9.07 504.4
7th 11th 13th
8.5 7.7 4.3
7.4 3.4 3.2
8.4 5.0 4.7
7.2 4.1 3.2
6.1 6.4 2.6
3.8 3.0 1.7
operation ratio)
7th 11th 13th
20.09 4.165 3.773
34.03 7.055 6.391
68.47 14.20 12.86
98.40 20.40 18.48
161.5 33.49 30.34
237.4 49.22 44.58
318.2 65.96 59.75
17th 19th 23rd
3.1 2.6 1.8
1.9 1.7 1.3
3.2 3.0 2.2
2.4 1.6 1.4
2.7 1.5 1.5
1.4 1.0 0.7
17th 19th 23rd
2.107 1.519 1.274
3.569 2.573 2.158
7.181 5.177 4.342
10.32 7.440 6.240
16.94 12.21 10.24
24.90 17.95 15.05
33.37 24.06 20.18
3. Precautions for Use of the Inverter
3.2 Power supply harmonics
1
2
25th
3
4
5
6
7
8
9
10
25th
0.882
1.494
3.006
4.320
7.092
10.42
13.97
97