Fuji Electric FRENIC MEGA G2 Series - 11.11 DC Reactors (DCRs)

11.11 DC Reactors (DCRs)
11-61
SELECTING PERIPHERAL EQUIPMENT
Chap 11
11.11 DC Reactors (DCRs)
These reactors are mainly used for “coordinating power supply” and “improving input power factor (for reducing
harmonics)”. If connecting to an HND specification inverter, select with an HND specification standard applicable
motor.
If using motors with output of 75 kW or higher, be sure to use a DC reactor (DCR).
For coordinating power supply
• Use a DCR when the capacity of a power supply transformer exceeds 500 kVA and is 10 times or more the rated
inverter capacity. In this case, the percent reactance of the power supply decreases, and harmonic components
and their peak value increase. These factors may break rectifiers or capacitors in the converter section of inverter,
or decrease the capacitance of the capacitor (which can shorten the inverter’s service life).
• Also use a DCR when there are thyristor-driven loads or when phase-advancing capacitors are being turned
ON/OFF.
• Use a DCR when the interphase voltage unbalance ratio of the inverter power supply exceeds 2%.
67
(V)voltageaveragephase-Three
(V)voltage Min.-(V)voltage Max.
=(%)unbalance voltageInterphase 
For input power factor correction (for suppressing harmonics)
Generally a capacitor is used to improve the power factor of the load, however, it cannot be used in a system that
includes an inverter. Using a DCR increases the reactance of inverter’s power supply so as to decrease harmonic
components on the power supply lines and improve the power factor of inverter. Using a DCR improves the input
power factor to approximately 86% to 95%.
• At the time of shipping, a jumper bar is connected across terminals P1 and P (+) on the terminal block.
Remove the jumper bar when connecting a DCR.
(A shorting bar is not connected on inverters with output of 75 kW or higher.)
• If a DCR is not going to be used, do not remove the jumper bar.
FRENIC-MEGA
Fig. 11.11-1 External view of DC reactor (DCR) and connection example
L1/R
L2/S
L3/T
U
V
W
G
電源
P1 P(+)
DCR
P1
G
Ｍ
３～
P(+)
モータ
Power
supply
Motor