Download  Print this page

Mitsubishi Electric 800 Series Hardware Instruction Manual Page 85

Separated converter type.
Hide thumbs

Advertisement

 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
83), harmonics must be calculated by the equation in next subheading.
P0 = Σ (Ki × Pi) [kVA]
Ki: Conversion factor (Refer to
Pi: Rated capacity of harmonic generating equipment
i: Number indicating the conversion circuit type
 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
 Rated capacities and outgoing harmonic currents of inverter-driven motors
Rated
current (A)
Applicable
motor (kW)
400 V
75
123
90
147
110
179
132
216
160
258
220
355
250
403
280
450
315
506
355
571
400
643
450
723
500
804
560
900
630
1013
 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.
 Harmonic suppression techniques
No.
Item
Reactor installation (FR-
1
HAL)
High power factor
2
converter (FR-HC2)
Installation of power factor
3
improving capacitor
Transformer multi-phase
4
operation
5
Passive filter (AC filter)
6
Active filter
84
3. PRECAUTIONS FOR USE OF THE INVERTER
3.2 Power supply harmonics
page
83.)
*1
[kVA]
page
83.
Fundamental
wave current
Rated
converted
capacity
from 6.6 kV
(kVA)
(mA)
7455
87.2
8909
104
10848
127
13091
153
15636
183
21515
252
24424
286
27273
319
30667
359
34606
405
38970
456
43818
512
48727
570
54545
638
61394
718
With the DC reactor equipped on its DC side, the converter unit (FR-CC2) can suppress the outgoing
harmonic current. Install an AC reactor (FR-HAL) on the AC side of the inverter to further suppress
outgoing harmonic currents.
This converter trims the current waveform to be a sine waveform by switching the rectifier circuit
(converter module) with transistors. Doing so suppresses the generated harmonic amount significantly.
Connect it to the DC area of an inverter. Use the high power factor converter (FR-HC2) with the
accessories that come as standard.
When used with a reactor connected in series, the power factor improving correction capacitor can
absorb harmonic currents.
Use two transformers with a phase angle difference of 30° in combinations of
provide an effect corresponding to 12 pulses, reducing low-degree harmonic currents.
A capacitor and a reactor are used together to reduce impedances at specific frequencies. Harmonic
currents are expected to be absorbed greatly by using this technique.
This filter detects the current in a circuit generating a harmonic current and generates a harmonic current
equivalent to a difference between that current and a fundamental wave current to suppress the
harmonic current at the detection point. Harmonic currents are expected to be absorbed greatly by using
this technique.
*1
Rated capacity: Determined by the capacity of the applied
motor and found in the following table. 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.
Outgoing harmonic current converted from 6.6 kV (mA) (with a DC
reactor, 100% operation ratio)
5th
7th
11th
2237
969
626
2673
1158
748
3254
1410
911
3927
1702
1100
4691
2033
1313
6455
2797
1807
7327
3175
2052
8182
3545
2291
9200
3987
2576
10382
4499
2907
11691
5066
3274
13146
5696
3681
14618
6335
4093
16364
7091
4582
18418
7981
5157
Description
13th
17th
19th
373
350
239
445
419
285
542
510
347
655
615
419
782
735
500
1076
1011
688
1221
1148
782
1364
1282
873
1533
1441
981
1730
1627
1107
1949
1832
1247
2191
2060
1402
2436
2290
1559
2727
2564
1746
3070
2886
1965
to Δ and Δ to Δ, to
page
23rd
25th
224
164
267
196
325
239
393
288
469
344
645
473
733
537
818
600
920
675
1038
761
1169
857
1315
964
1462
1072
1636
1200
1842
1351

Advertisement

Table of Contents

Comments to this Manuals

Symbols: 0
Latest comments: