HEIDENHAIN MANUALplus 620 Technical Manual page 929

Actual DC-line voltage on non-regenerative power modules (in the
commissioning flow chart = (5))
Entering the DC-link voltage in MP_ampBusVoltage is also used by the
control to ascertain the magnetizing current. At a line voltage of 400 V
(interlinked), the rectified DC-link voltage is 565 V. If the fluctuation range of
the line voltage is known (e.g. +/– 10 %), use the minimum value UNetz,Min
of the line voltage to calculate the DC-link voltage according to the following
equation:
⋅
Uz = 2 U
NetzMin
If in addition you use a series reactor—for example to comply with EMC
standard—then remember that the DC-link voltage can be reduced. So enter,
if possible, the measured value of the DC-link voltage. If a measurement is not
possible, then reduce the value calculated on the basis of the line voltage by
approx. 3 %.
Example: Line voltage UNetz = 380 V =>
MP_ampBusVoltage = 0.97 · 537 = 521.
If the line voltage in the machine's work area is less than the line voltage
during commissioning, enter the value of the DC-link voltage at its later
location during commissioning.
Stationary line voltage stable? ((6) in the commissioning flow chart)
Any stationary fluctuating line voltage is to be accounted for by using the
smallest occurring value for calculating the entry in MP_ampBusVoltage,
insofar as it has not already been accounted for through minimum line voltage.
This ensures that the required magnetizing current is available, in particular
during the acceleration phase. An excessively large DC-link voltage could lead
to increased following error during acceleration and at high speeds.
Line voltage stable under load? ((7) in the commissioning flow chart)
If you use an unstable power network on the machine, it can reduce the line
voltage under load (when the axes are accelerated) and therefore also reduce
the DC-link voltage. So it might be necessary to adjust the entry in
MP_ampBusVoltage for the load. Compare the behavior of one axis during
acceleration of only that axis (light load) with its behavior during acceleration
of all axes, perhaps including the spindle (maximum load). If there are no
differences in the following error or nominal current, the entry in
MP_ampBusVoltage can remain unchanged. If these signals show anything
unusual (surge in current or following error), reduce the entry in
MP_ampBusVoltage accordingly.
January 2012 6.16 The Control Loop 929