Calculation Of The Regenerative Energy - Mitsubishi Electric MDS-D-SPJ3 Specification Manual

7-3-2 Calculation of the regenerative energy

Calculate the regenerative energy for stopping from each axis' rapid traverse rate (maximum rotation speed
for spindle), and select a regenerative resistor having a capacity that satisfies the positioning frequency
determined from the machine specifications.
(1) For horizontal servo axis and spindle
The regenerative energy E
13). If the E value is negative, all of the regenerative energy is absorbed by the capacitor in the drive unit
R
(capacitor regeneration), and the energy consumed by the regenerative resistor is zero (E
E 5.48 × 10
R
(Example)When a load with the same inertia as the motor is connected to the HF54, determine the
regenerative energy to stop from the rated rotation speed. Note that the drive unit is MDS-D-SVJ3-07NA in
this case.
According to expression (7-13), the regenerative energy E
-7
E =5.48×10 ×0.85×(6.1+6.1)×3000
R
Drive unit
MDS-D-SVJ3-03NA
MDS-D-SVJ3-04NA
MDS-D-SVJ3-07NA
MDS-D-SVJ3-10NA
MDS-D-SVJ3-20NA
MDS-D-SVJ3-35NA
Motor
HF75,105
HF54, 104, 154, 224, 123, 223, 142
HF204, 354, 303, 302
HF-KP13
HF-KP23
HF-KP43
HF-KP73
The charging energy values apply when the unit input power voltage is 220V. If the input voltage is
POINT
higher, the charging energy decreases, and the regenerative energy increases.
consumed by the regenerative resistor can be calculated from expression (7-
R
-7 2
(J J ) N Ec
･ ･
L M
η
:Motor reverse efficiency
J
:Motor inertia
L
J
:Load inertia
M
N :Motor speed
Ec :Unit charging energy
2
-18 =33.1(J)
Drive unit charging energy
Charging energy Ec (J)
9
11
18
30
40
40
Motor reverse efficiency
Motor reverse
efficiency η
0.85
0.85
0.85
0.55
0.70
0.85
0.85
MDS-D-SVJ3/SPJ3 Series Specifications Manual
7-3 Selection of the regenerative resistor
(J)
••• (7-13)
(kg•cm
(kg•cm
(r/min)
(J)
is:
R
Drive unit
MDS-D-SPJ3-075NA
MDS-D-SPJ3-22NA
MDS-D-SPJ3-37NA
MDS-D-SPJ3-55NA
MDS-D-SPJ3-75NA
MDS-D-SPJ3-110NA
Motor
All spindle motors
= 0).
R
2
)
2
)
Charging energy Ec(J)
18
40
40
45
45
90
Motor reverse
efficiency η
0.90
7 - 15