POWER ELECTRONICS AND CABINET FEATURES
PRODUCT
ACS1000W
DOCUMENT KIND
User manual
DOCUMENT ID.
3BHS213400 E01
REV.
J
LANG.
en
PAGE
42/166
3.4.7.1. Control principle
If the DC-link voltage rises above a preset limit, the control system of the
ACS1000W automatically activates the braking chopper. A rise of the DC-link
voltage can be caused by a machine, feeding into the DC link or by an increase of
the voltage in the rectifier of the ACS1000W.
Figure 3
-
13 Braking chopper design
3.4.7.2. Monitoring and protective functions
Current monitoring
Input currents of the braking chopper are monitored for overcurrent and imbalance
in order to detect any defective component in the circuit. The current can become
imbalanced if one of the IGCTs conducts a current permanently or if an IGCT fails
to be switched on.
If a short-circuit or an imbalance is detected in the braking chopper, the drive is
shut down.
Thermal protection
The braking chopper and the braking resistors are monitored for over-temperature
by the ACS1000W.
1) Semiconductor stack
1
