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MITSUBISHI ELECTRIC FR-S520 User Manual

Page 31

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Table 2 Conversion Factors for FR-S500 Series

Class

Circuit Type

Conversion Factor (Ki)

Without reactor

K31

=

3.4

With reactor (AC side)

K32

=

1.8

With reactor (DC side)

K33

=

1.8

3

3-phase bridge
(Capacitor-
smoothed)

With reactors (AC, DC sides)

K34

=

1.4

Table 3 Equivalent Capacity Limits

Received Power Voltage

Reference Capacity

6.6kV

50 kVA

22/33 kV

300 kVA

66kV or more

2000 kVA

Table 4 Harmonic Contents (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

(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 a 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 converterd 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.

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