Dc Link Options; Capacitor Module With 4.1 Mf Or 20 Mf - Siemens SIMODRIVE 611 Planning Manual

05.01
6.6

DC link options

6.6.1

Capacitor module with 4.1 mF or 20 mF

Description
The capacitor modules are used to increase the DC capacitance. In this case, a
brief power failure can be buffered and it is also possible to buffer the braking
energy.
The modules differ as follows:
S
S
The capacitor modules have a ready display which is lit above a DC link voltage
of approx. 300 V. This also means that an internal fuse failure can be detected.
However, this does not reliably monitor the charge condition.
The 4.1 mF module does not have a pre–charging circuit, which means that it
can directly absorb the energy during dynamic braking operations as it is di-
rectly connected to the DC link which also means that it can operate as dynamic
energy storage device. For these modules, the charge limits of the line supply
modules must be taken into account.
For 20 mF modules, pre–charging is realized through an internal series resistor
in order to limit the charge current and to de–couple the module from the central
pre–charging. This module cannot absorb any energy generated from dynamic
switching operation, as the series resistor limits the charging current. During
power failures, a diode couples this capacitor battery to the system DC link
which it then supports.
Note
The capacitor modules may only be used in conjunction with SIMODRIVE 611
line supply infeed modules.
The modules are suitable for internal and external cooling.
 Siemens AG 2001 All rights reserved
SIMODRIVE 611 Planning Guide (PJU) – 05.01 Edition
Module with 4.1 mF ––> used as dynamic energy storage device
Module with 20 mF ––> used to buffer power failures
6 Infeed Modules
6.6 DC link options
6-191
6