Mitsubishi Electric FR-F500 Instruction Manual page 51

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
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
Fundamental
Applied Rated Wave Current
Motor Current Converted
(kW) [A] 400V from 6.6kV
(mA)
75 123 8,200
90 147 9,800
110 179 11,933
132 216 14,400
160 258 17,200
200 323 21,553
220 355 23,667
250 403 26,867
3) Harmonic suppression technique requirement
If the outgoing harmonic current is higher than the maximum value per 1kW (contract power) × contract
power, a harmonic suppression technique is required.
4) Harmonic suppression techniques
No. Item
Reactor installation
1
(ACL, DCL)
High power factor
converter
2
(MT-HC)
Installation of power
3 factor improving
capacitor
Transformer multi-
4
phase operation
5 AC filter
6 Active filter
Rated
Capacity
(kVA)
5th
87 2,460
104 2,940
127 3,580
153 4,320
183 5,160
229 6,460
252 7,100
286 8,606
Install a reactor (ACL) in the AC side of the inverter or a reactor (DCL) in its DC side or both to
suppress outgoing harmonic currents.
The converter circuit is switched on-off to convert an input current waveform into a sine wave,
suppressing harmonic currents substantially. The high power factor converter (MT-HC) is used with
the standard accessory.
When used with a series reactor, the power factor improving capacitor has an effect of absorbing
harmonic currents.
Use two transformers with a phase angle difference of 30° as in
an effect corresponding to 12 pulses, reducing low-degree harmonic currents.
A capacitor and a reactor are used together to reduce impedance at specific frequencies, producing
a great effect of absorbing harmonic currents.
This filter detects the current of 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
a harmonic current at a detection point, providing a great effect of absorbing harmonic currents.
33
INSTALLATION AND WIRING
* 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.
Fundamental Wave Current Converted from 6.6kV
(With DC reactor, 100% operation ratio)
(mA)
7th 11th 13th 17th
1,066 689 410 385
1,274 823 490 461
1,551 1,002 597 561
1,872 1,210 720 677
2,236 1,445 860 808
2,799 1,809 1,077 1,012
3,077 1,988 1,183 1,112
3,493 2,257 1,343 1,263
Description
19th 23rd 25th
262 246 180
314 294 216
382 358 263
461 432 317
550 516 378
689 646 474
757 710 521
860 806 591
- ∆ , ∆ - ∆ combination to provide
2