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Noise and leakage currents
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(According to Table 2)
Pi: Rated capacity of harmonic generating equipment
i : Number indicating the conversion circuit type
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 of inverter-driven motors
Rated Current
Applied
(A)
Motor
(kW)
200V
400V
0.4
1.61
0.81
0.75
2.74
1.37
1.5
5.5
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
11
36.9
18.5
15
49.8
24.9
18.5
61.4
30.7
22
73.1
36.6
30
98.0
49.0
37
121
60.4
45
147
73.5
55
180
89.9
Rated Current
Applied
(A)
Motor
(kW)
200V
400V
75
245
123
90
293
147
110
357
179
46
[kVA]
*
Fundamental
Wave Current
Rated
Converted
Capacity
from 6.6kV
(kVA)
(mA)
49
0.57
83
0.97
167
1.95
240
2.81
394
4.61
579
6.77
776
9.07
1121
13.1
1509
17.6
1860
21.8
2220
25.9
2970
34.7
3660
42.8
4450
52.1
5450
63.7
Fundamental
Wave Current
Rated
Converted
Capacity
from 6.6kV
(kVA)
(mA)
7455
87.2
8909
104
10848
127
* 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.
Outgoing Harmonic Current Converted from 6.6kV (mA)
(No reactor, 100% operation ratio)
5th
7th
11th
31.85
20.09
4.165
53.95
34.03
7.055
108.6
68.47
14.20
156.0
98.40
20.40
257.1
161.5
33.49
376.1
237.4
49.22
504.4
318.2
65.96
728.7
459.6
95.29
980.9
618.7
128.3
1209
762.6
158.1
1443
910.2
188.7
1931
1218
252.5
2379
1501
311.1
2893
1825
378.3
3543
2235
463.3
Outgoing Harmonic Current Converted from 6.6kV (mA)
(With DC reactor, 100% operation ratio)
5th
7th
11th
2237
969
626
2673
1158
748
3254
1410
911
13th
17th
19th
3.773
2.107
1.519
6.391
3.569
2.573
12.86
7.181
5.177
18.48
10.32
7.440
30.34
16.94
12.21
44.58
24.90
17.95
59.75
33.37
24.06
86.32
48.20
34.75
116.2
64.89
46.78
143.2
79.98
57.66
170.9
95.46
68.82
228.7
127.7
92.07
281.8
157.4
113.5
342.7
191.4
138.0
419.7
234.4
169.0
13th
17th
19th
373
350
239
445
419
285
542
510
347
23rd
25th
1.274
0.882
2.158
1.494
4.342
3.006
6.240
4.320
10.24
7.092
15.05
10.42
20.18
13.97
29.15
20.18
39.24
27.16
48.36
33.48
57.72
39.96
77.22
53.46
95.16
65.88
115.7
80.10
141.7
98.10
23rd
25th
224
164
267
196
325
239
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