INSTALLATION AND WIRING
30
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
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:
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.
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.
Table 5 Rated Capacities and Outgoing Harmonic Currents for Inverter Drive
Rated Current [A]
Fundamental
Wave Current
Converted
from 6.6kV
Rated
Capacity
Fundamental Wave Current Converted from 6.6kV
(No reactor, 100% operation ratio)
Applied
Motor
(kW)
200V
400V
(mA)
(kVA)
5th
7th
11th
13th
17th
19th
23rd
25th
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
Note: When a motor of 3.7kW or less capacity is driven by a transistorized inverter of more than 3.7kW. For
example, when a 3.7kW or less motor is driven by a 5.5kW transistorized inverter, the transistorized
inverter is not the target of the household appliances/general-purpose products guideline, but because
they must be included in the calculation of the harmonic current of the guideline, the fundamental wave
input currents are indicated.
3) Harmonic suppression technique requirement
If the outgoing harmonic current is higher than; maximum value per 1kW (contract power)
×
contract
power, a harmonic suppression technique is required.
2
