Chapter 2 - Overview
DCS 500 12-Pulse Planning and Start-Up
2 - 1
The 12-pulse parallel connection produces the following advan-
tages:
✸
Reduction in power converter’s effects on the mains supply
network
Reduced harmonics; different frequencies in the mains
✸
Large output DC currents
Doubling of the output currents die to parallel connection of two
6-pulse standard power converters to form a 12-pulse circuit
✸
Improved current ripple
Smaller current ripple, higher frequency content, smaller torque
pulsation
Basically, the 12-pulse connection is a classical master-slave con-
figuration with a speed-controlled 6-pulse master power converter
and a current-controlled 6-pulse slave power converter.
The 12-pulse parallel connection is obtained by feeding the slave
with a mains supply offset by 30 degrees compared to the master
and joining the power converter outputs on one side over an inter-
phase reactor.
The 12-pulse mode has been implemented in the standard soft-
ware, and will not become operative until after parameterization.
After a few signals have been replaced for switch-on and switch-off,
and the specific master/slave parameters have been set, the two
power converters will work in the usual way. The only distinctive
feature compared with the classical 6-pulse variant is that the two
power converters are synchronized for reversing the bridges.
This manual must be consulted for 12-pulse mode in addition to the
following DCS 500 manuals:
DCS 500 Start-up Instructions
DCS 500 Installation and Start-Up Manual
DCS 500 Programming Manual
