Omron EasySpeed 3G3JE, Руководство пользователя

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Chapter 2
2-35
Design
● Calculating the Equivalent Capacity per Inverter
The equivalent capacity for an inverter is calculated as follows:
Equivalent capacity = Inverter’s rated input capacity (Pi) x Coefficient
Here, the Inverter’s rated input capacity (Pi) is calculated based on the rated capacity of the appli-
cable motor, as shown in the following table.
Inverter’s Rated Input Capacity
The coefficient is as shown in the following table for a three-phase general-purpose inverter.
■
Calculating the Harmonic Current per Inverter
Use the following formula: nth harmonic current [A] =
Fundamental frequency input current [A] x nth harmonic current ratio (%)/100
Here, the values in the following table are used for the fundamental frequency input current and
converted for a received voltage of 6.6 kV.
The following table is used to obtain the nth harmonic current ratio (%). Normally calculations are
performed only for the 5th and 7th harmonics.
Three-phase Bridge (Capacitor Smoothing)
(Unit: %)
Motor capacity
(kW)
Rated input capacity (Pi)
(kVA)
200 V 400 V
0.4 0.57
0.75 0.97
1.5 1.95
3 Three-phase
bridge (capaci-
tor smoothing) 3-1 No reactor K
31
= 3.4 General-purpose inverters
Servo amplifiers
Elevators
Refrigeration and air condi-
tioning equipment
Other general-purpose
equipment
3-2 Reactor on AC side K
32
= 1.8
3-3 Reactor on DC side K
33
= 1.8
3-4 Reactors on AC and DC side K
34
= 1.4
Applicable motor [kW] 0.4 0.75 1.5
Fundamental frequency
input current [A] 200 V 1.61 2.74 5.50
400 V 0.81 1.37 2.75
Value converted for 6.6 kV [mA] 49 83 167
Harmonic number 5 7 11 13 17 19 23 25
No reactor 65 41 8.5 7.7 4.3 3.1 2.6 1.8
Reactor on AC side 38 14.5 7.4 3.4 3.2 1.9 1.7 1.3
Reactor on DC side 30 13 8.4 5.0 4.7 3.2 3.0 2.2
Reactors on AC and DC side 28 9.1 7.2 4.1 3.2 2.4 1.6 1.4