YASKAWA SGDH - Calculating the Required Capacity of Regenerative Resistors

11.1 Servomotor Capacity Selection Examples
11-7
11
11.1.3 Calculating the Required Capacity of Regenerative Resistors
(1) Simple Calculation
When driving a servomotor with the horizontal axis, check the external regenerative resistor requirements using
the calculation method shown below.
(a) SERVOPACKs with Capacities of 400 W or Less
SERVOPACKs with capacities of 400 W or less do not have built-in regenerative resistors. The energy that
can be charged with capacitors is shown in the following table. If the rotational energy in the servomotor
exceeds these values, then connect an external regenerative resistor.
Calculate the rotational energy E
s
in the servomotor from the following equation:
E
S
= J × (N
M
)
2
/182 (joules)
• J = J
M
+ J
L
• J
M
: Servomotor rotor moment of inertia (kg·m
2
)
• J
L
: Load converted to shaft moment of inertia (kg·m
2
)
• N
M
: Rotation speed used by servomotor (min
-1
)
Voltage Applicable SERVO-
PACKs
Regenerative
Energy that Can
be Processed
(joules)
Remarks
100 V SGDH-A3BE
7.8
Value when main circuit input voltage is 100 VAC
SGDH-A5BE to -02BE
15.7
200 V SGDH-A3AE, -A5AE
18.5
Value when main circuit input voltage is 200 VAC
SGDH-01AE to -04AE
37.1