CHAPTER 15 APPENDIXES

(9) Regenerative power

Regenerative power is caused during deceleration.

E1[J] = (2π/60) × TDC [Nm] × N [r/min] × tDC × (1/2)

= (2π/60) × -0.75 × 3000 × 0.05 × (1/2)

≒ -5.9 J

Accumulated energy on main circuit capacitor (E2)

E2[J] = (1/2) × C[F] × V2

= (1/2) × (440 × 10-6) × {3902 - (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 μF.

P[W] = ( | E1 | - E2) / (tcyc)

=( | -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.

15

15-28 Capacity Selection Calculation