36
INSTALLATION AND WIRING
1) Calculation of equivalent capacity P0 of harmonic generating equipment
The "equivalent capacity" is the capacity of a 6-pulse converter converted from the capacity of consumer's
harmonic generating equipment and is calculated with the following equation. If the sum of equivalent
capacities is higher than the limit in Table 3, harmonics must be calculated with the following procedure:
2) Calculation of outgoing harmonic current
Outgoing harmonic current = fundamental wave current (value converted from received power voltage)
×
operation ratio
×
harmonic content
•
Operation ratio: Operation ratio = actual load factor × operation time ratio during 30 minutes
•
Harmonic content: Found in Table 4.
Note: The fundamental wave input currents are indicated because when a motor whose capacity is 3.7kW or
less is driven by a more than 3.7kW inverter, e.g. when a 3.7kW motor is driven by a 5.5kW inverter,
the transistorized inverter is not covered by the harmonic suppression guideline for household
appliances and general-purpose products and must be included in the calculation of harmonic currents
for the guideline.
Table 3 Equivalent Capacity Limits
Received Power Voltage Reference Capacity
6.6kV 50kVA
22/33kV 300kVA
66kV or more 2000kVA
Table 4 Harmonic Content (Values at the fundamental current of 100%)
Reactor 5th 7th 11th 13th 17th 19th 23rd 25th
Not used 65 41 8.5 7.7 4.3 3.1 2.6 1.8
Used (AC side) 38 14.5 7.4 3.4 3.2 1.9 1.7 1.3
Used (DC side) 30 13 8.4 5.0 4.7 3.2 3.0 2.2
Used (AC, DC sides) 28 9.1 7.2 4.1 3.2 2.4 1.6 1.4
P0 =
Σ
(Ki
×
Pi) [kVA]
Ki: Conversion factor (refer to Table 2)
Pi: Rated capacity* of harmonic generating equipment [kVA]
i : Number indicating the conversion circuit type
* Rated capacity: Determined by the capacity
of the applied motor and found in Table 5. It
should be noted that the rated capacity
used here is used to calculate generated
harmonic amount and is different from the
power supply capacity required for actual
inverter drive.
Table 5 Rated Capacities and Outgoing Harmonic Currents for Inverter Drive
Applied
Motor
(kW)
Rated Current
[A]
Fundamental
Wave Current
Converted
from 6.6kV
Rated
Capacity
Outgoing Harmonic Current Converted from 6.6kV
(No reactor, 100% operation ratio)
200V 400V (mA) (kVA) 5th 7th 11th 13th 17th 19th 23rd 25th
0.4 1.61(Note) 0.81 49 0.57 31.85 20.09 4.165 3.773 2.107 1.519 1.274 0.882
0.75 2.74(Note) 1.37 83 0.97 53.95 34.03 7.055 6.391 3.569 2.573 2.158 1.494
1.5 5.50(Note) 2.75 167 1.95 108.6 68.47 14.20 12.86 7.181 5.177 4.342 3.006
2.2 7.93(Note) 3.96 240 2.81 156.0 98.40 20.40 18.48 10.32 7.440 6.240 4.320
3.7 13.0(Note) 6.50 394 4.61 257.1 161.5 33.49 30.34 16.94 12.21 10.24 7.092
5.5 19.1 9.55 579 6.77 376.1 237.4 49.22 44.58 24.90 17.95 15.05 10.42
7.5 25.6 12.8 776 9.07 504.4 318.2 65.96 59.75 33.37 24.06 20.18 13.97
11 36.9 18.5 1121 13.1 728.7 459.6 95.29 86.32 48.20 34.75 29.15 20.18
15 49.8 24.9 1509 17.6 980.9 618.7 128.3 116.2 64.89 46.78 39.24 27.16
18.5 61.4 30.7 1860 21.8 1209 762.6 158.1 143.2 79.98 57.66 48.36 33.48
22 73.1 36.6 2220 25.9 1443 910.2 188.7 170.9 95.46 68.82 57.72 39.96
30 98.0 49.0 2970 34.7 1931 1218 252.5 228.7 127.7 92.07 77.22 53.46
37 121 60.4 3660 42.8 2379 1501 311.1 281.8 157.4 113.5 95.16 65.88
45 147 73.5 4450 52.1 2893 1825 378.3 342.7 191.4 138.0 115.7 80.10
55 180 89.9 5450 63.7 3543 2235 463.3 419.7 234.4 169.0 141.7 98.10
