80
MSD Multi-Axis System Operation Manual DC-AC Servo Drive
9.7.4
Selection of suitable Power Supply Unit
NOTE
During all the following dimensioning calculations, always pay attention to the
Operation Manual MSD Power Supply Unit (ID no. CA97556-001).
To identify a suitable Power Supply Unit, a power/time diagram for a complete machine
cycle must be available for all axes. Figur
The power required by each individual axis at each point in time is added together to
produce the power/time diagram for the Power Supply Unit. The following characteristic
data for the Power Supply Unit can be derived from this diagram:
•
Nominal supply power
•
Maximum supply power
•
Nominal regenerative power
•
Maximum regenerative power
With a low simultaneity factor in the axis group, it may be possible to select the largest
axis as an AC-AC Servo Drive that can take over the supply for the entire axis group.
However, it is then not possible to feed power back to the supply system. Regenerative
power produced must be dissipated via a braking resistor and converted into heat.
NOTE
If the supply system fails, due to the principle of operation the Power Supply
Unit can no longer feed back power. For this special situation, we therefore
recommend you to use a braking resistor with a power rating that should be
designed for this braking process.
9.7.2
Selection of suitable gearboxes and motors
The gearbox is selected depending on the application, either to obtain the maximum
dynamic performance, of the most efficient continuous operation possible
− Formula for gear ratio (for optimal dynamic performance):
˜
J
load
J
Motor
i =
− Formula for gear ratio (for good utilisation during continuous operation):
n
N
n
load
i =
Motors are selected based on the following criteria:
•
M
max
•
n
max
•
M
Rated
> M
eff
Define the encoder system depending on the equirement in your application in relation
to absolute accuracy, reproducible accuracy, robustness and determination of the
machine zero point:
•
Resolver
•
Sin/Cos encoder, single-turn
•
Sin/Cos encoder, multi-turn
9.7.3
Selection of suitable DC-AC Servo Drives
After the motors have been selected, matching DC-AC Servo Drives are selected based
on the following criteria:
•
Maximum current
•
Rated current
moog
Id. no.: CA97554-001 0
5
/2017
9 Planning
