4 System Design
4 - 48
G5-series Linear Motors/Servo Drives With Built-in EtherCAT Communications
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Determining the Capacity of Regenerative Energy Absorption by Built-in
Capacitors
If both the values Eg1 and Eg2 [J] mentioned above are equal to or less than the value of the Servo
Drive’s regenerative energy that can be absorbed by built-in capacitors Ec [J], the Servo Drive can
process regenerative energy only by its built-in capacitors.
If either the value Eg1 or Eg2 [J] exceeds the value of the Servo Drive’s regenerative energy that can be
absorbed by built-in capacitors Ec [J], however, use the following equations to determine the average
regeneration power Pr [W].
Note
If the expression (E
g1
- Ec) result is zero or less, regards it as 0. The expression (E
g2
- Ec) must also be
handled in the same way.
The above expressions calculate the average regeneration power Pr [W], which cannot be absorbed by
the built-in capacitors. If this average regeneration power Pr [W] is equal to or less than the average
amount of regeneration that can be absorbed by the Servo Drive’s Internal Regeneration Resistor, the
Servo Drive can independently process the regenerative energy.
If this average regeneration power Pr [W] cannot be processed only by the Servo Drive, take the
following processes.
•
Connect an External Regeneration Resistor. (Regeneration process capacity improves.)
•
Reduce the operation speed. (The amount of regeneration is proportional to the square of the
speed.)
•
Lengthen the deceleration time. (Regenerative energy per unit time decreases.)
•
Lengthen the operation cycle, i.e., the cycle time. (Average regenerative power decreases.)
E
g
= (E
g1
- E
c
) + (E
g2
- E
c
) [J]
P
r
= E
g
/ T [W]
P
r
E
g
E
c
T
: Average regeneration power that must be absorbed in 1 cycle of operation [W]
: Regenerative energy that must be absorbed in 1 cycle of operation [J]
: Regenerative energy that can be absorbed by built-in capacitors [J]
: Operation cycle [s]
