Fuji Electric ALPHA5 Smart, User Manual

Page: 620 / 636

CHAPTER 15 APPENDIXES
15-28
Capacity Selection Calculation
15
(9) Regenerative power
Regenerative power is caused during deceleration.
Accumulated energy on main circuit capacitor (E
2
)
E
2
[J] = (1/2) × C[F] × V
2
= (1/2) × (440 × 10
-6
) × {390
2
- (200
√
2)
2
}
= 15.8 J
Regenerative energy (P)
The capacitor for the servo amplifier of 0.2 kW or less has a capacity of 440 μ F.
P[W] = ( | E
1
| - E
2
) / (t
cyc
)
=( | -5.9 | - 15.8) / 0.5
= -19.8 J
As P is equal to or less than 0, no external regenerative resistor is required since the regenerative
energy can be processed in the servo amplifier.
E
1
[J] = (2
π
/60) × T
DC
[Nm] × N [r/min] × t
DC
× (1/2)
= (2
π
/60) × -0.75 × 3000 × 0.05 × (1/2)
≒
-5.9 J