Delta ASD-A2-0121 Series User Manual page 54

Chapter 2 Installation
Servo Drive
(kW)
0.75 ECMA-L△1305
1.5 ECMA-L△1313
3.0
ECMA-L△1830
Medium-
3.0 ECMA-J△1330
High
Inertia
4.5 ECMA-L△1845
5.5 ECMA-L△1855
7.5
ECMA-L△1875
1.0 ECMA-L△1308
High
Inertia
1.5 ECMA-M△1309
Eo= J * wr /182 (joule), Wr: r/min
2
Assume that the load inertia is N times to the motor inertia and the motor decelerates from
3000 r/min to 0, its regenerative energy is (N+1) x Eo. The consumed regenerative resistor is
(N+1) × Eo - Ec joule.
regenerative resistor it needs is 2× ((N+1) x Eo - Ec) / T.
Followings are the calculation procedure:
Step
Set the capacity of regenerative
1
resistor to the maximum
2 Set T cycle of back and forth operation
3 Set the rotational speed wr
4 Set the load/motor inertia ratio N
Calculate the maximum regenerative
5
Set the absorbable regenerative
6
Calculate the needful capacitance of
7
regenerative resistor
Take 400 W as the example. The cycle of back and forth operation is T = 0.4 sec, the maximum
speed is 3000 r/min, and the load inertia is 7 times to the motor inertia. Then, the needful power of
regenerative resistor is 2 × ((7+1) × 1.37 – 8) / 0.4 = 14.8 W. If it is smaller than the built-in capacity
of regenerative resistor, the built-in 60 W regenerative resistor will do. Generally speaking, when
the need of the external load inertia is not much, the built-in regenerative is enough. The smaller
power of the regenerative resistor it is, the more energy it accumulates and the higher temperature
it will be. When the temperature is higher than a specific value, AL005 occurs.
Rotor Inertia
Motor
J
(× 10
If the cycle of back and forth operation is T sec, then the power of
Item
energy Eo
energy Ec
Regenerative power
from empty load
3000 r/min to stop
kg.m2)
-4
Eo (joule)
13.1 16.20
23.6 29.18
54.95 67.93
12.7 15.70
77.75 96.12
99.78 123.35
142.7 176.41
17.1 84.56
11.18 55.29
Calculation and Setting Method
Set P1-53 to the maximum value
Enter by the user or read via P0-02
Enter by the user or read via P0-02
Refer to the above table
2 x ((N+1) x Eo – Ec) / T
The maximum
regenerative power of
capacitance
Ec (joule)
42.43
42.43
42.43
42.43
51.17
57.41
62.40
42.43
57.41
Enter by the user
Eo= J * wr /182
2
ASDA-A2
2-15