Control System Response; Axis Behavior Depending On The Enable Signals - Siemens SINUMERIK 840D sl Function Manual

The energy stored in an axis can be calculated as follows:
This energy is fed back into the DC link with an efficiency of approx. 90%:
When using infeeds with a high power rating (55, 80, 120 kW) for generator operation, it is
recommended to use a dedicated axis with additional flywheel effect. For this axis, after the
drive has accelerated to the rated speed, energy is only required to compensate for friction
losses.
However, in principle, any axis can be used for generator operation, if this is not directly
involved in extended stopping and retraction or in couplings that must be specifically
maintained.
In order to prevent that the DC link voltage does not become too high when using generator
operation (limit value: pulse cancellation, drive) and as a consequence that the pulses are
cancelled for the axes, adequately dimensioned pulsed resistor modules must be used or the
SINAMICS function "Vdc control, overvoltage monitoring".
6.2.10

Control system response

6.2.10.1

Axis behavior depending on the enable signals

Systematic
If an axis is configured as NC-controlled retraction axis:
MD37500, $MA_ESR_REACTION[
The following enable signals must be available to execute retraction motion in the case of
ESR:
• Axial ESR enable using system variable: $AA_ESR_ ENABLE[
• Axial retraction enable using a part program command: POLFMASK(<axis>)
If one of the two enable signals is not available, then in the case of ESR, the axis responds
corresponding to the following table:
Enable signals
<
• $AA_ESR_ ENABLE[
• No enable via POLFMASK
<
• $AA_ESR_ ENABLE[
• Enable via POLFMASK(<axis>)
Special Functions
Function Manual, 09/2011, 6FC5397-2BP40-2BA0
2
E = 1/2 * Θ * ω
Θ Total moment of inertia
ω Angular velocity at the instant in time that a switch-over is made to
generator operation
Response in the case of ESR
>
axis ] = 1 For the axis, implicit NC-controlled stopping becomes active, corresponding
to MD37500, $MA_ESR_REACTION[
>
axis ] = 0 Axis is a path axis:
For the axis, the ESR response is implicitly changed to NC-controlled
stopping. The response corresponds then to a configuration of MD37500,
$MA_ESR_REACTION[
Axis is a special axis:
The axis is stopped with rapid stop.
<axis>
] = 21
<
< >
axis ] = 22
R3: Extended stop and retract
6.2 Control-managed ESR
< >
axis ] = 1
>
axis ] = 22.
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