Mitsubishi Electric MELSERVO-J5 MR-J5 Series User Manual page 168

■Calculation of regenerative energy per cycle
As an example, calculate the regenerative energy in the following operation pattern with MR-J5W3-_G_ servo amplifier.
Servo motor speed
A-axis
B-axis
C-axis
Calculate the energy at each timing in one cycle. Energy is a positive value in power running and a negative value in
regeneration. Create a table like the one shown below, and write down the energy during power running/regeneration with
signs.
Timing (1)
A-axis E1A
B-axis E1B
C-axis E1C
Sum E1
Calculate the energy consumed by the regenerative resistor ER [J] with the following formula for the calculation results from
E1 to E11 with negative values.
When the absolute value of the value in E1 to E11 is assumed to be Es: ER [J] = η
If ER values are negative at all timings, the regenerative option is not needed. If the values of ER include positive values, from
the total of ERs whose subtraction results are positive and one-cycle period, the power consumption PR [W] of the
regenerative resistor can be calculated with the following equation.
PR [W] = total of positive ERs/one-cycle operation period (tf)
The regenerative option is not required when the PR value is equal to or less than the specification value for the built-in
regenerative power of the servo amplifier.
6 OPTIONS AND PERIPHERAL EQUIPMENT
166
6.2 Regenerative option
(1) (2) (3) (4) (5)
tf (one cycle) tf (one cycle)
(2) (3)
E2A E3A
E2B E3B
E2C E3C
E2 E3
(6) (7) (8) (9) (10)
(4) (5) (6)
E4A E5A E6A
E4B E5B E6B
E4C E5C E6C
E4 E5 E6
(11)
Time
Time
Time
(7) (8) (9)
E7A E8A E9A
E7B E8B E9B
E7C E8C E9C
E7 E8 E9
• E - E
m s c
(10) (11)
E10A E11A
E10B E11B
E10C E11C
E10 E11