YASKAWA SGD7W - Page 310

12.8 Regenerative Resistor
12.8.6 Selecting External Regenerative Resistor
12
SERVOPACK Peripheral Devices
12-41
Use the following equation to calculate the allowable frequency for regenerative operation.
• n = J
L
/J
M
• J
M
: Servomotor moment of inertia (kg⋅m
2
)
• J
L
: Load moment of inertia at motor shaft (kg⋅m
2
)
0
0
0
T
t
t
Maximum
motor speed
Maximum
torque
Maximum
torque
Regenerative
operation
(Operation cycle)
Allowable frequency: 1/T [times/min]
Operating Conditions for Calculating the Allowable Regenerative Frequency
Speed reference
Servomotor
motor speed
Servomotor-
generated
torque
Load moment of inertia = 0 (Servomotor only)
(1+ n)
×
2
Allowable frequency =
Maximum motor speed
Operating motor speed
(time/min)
Allowable frequency for regenerative
operation for Servomotor without load