Leadshine EL8-EC Series User Manual page 47

Theoretical selection of regenerative resistor
Without external loading torque, the need for an external regenerative resistor can be
determined as the flow chart below
N
No external
resistor needed
Start
Determine the
duration of motion
cycle T (s)
Determine motor max.
rotational velocity
V(rpm)
Determine motor load-
inertia ratio(N)
Calculate
regenerative energy
E1(J)
Determine energy
stored by capacitor
Ec（J）
Y
E1(J)>Ec（J）?
regenerative resistor
N
Use internal
regenerative resistor
User manual of EL8-EC***F AC Servo
T is the time for velocity to reach
max. velocity from 0 rpm and
decelerates back to 0rpm
Can be monitored on the front panel
Can be determined through inertia
measuring function
E1=(N+1)×Eo Eo=J×V^2/182
J: Motor unloaded rotational inertia
V: Motor rotational velocity
N: motor load-inertia ratio
Use table 2-5 to determine the maximum
regenerative energy stored by the capacitors
External
resistor needed
Calculate required
- - - - - - - - - Pr=
power rating Pr
Y
Pb>Pa?
Use external
regenerative resistor
Please consider external
factor(s) when using external
regenerative resistor
End
((E1-Ec)/T)
0.5
47