Elettronica Santerno SINUS K, User Manual

Page: 151 / 191

SINUS K
INSTALLATION
INSTRUCTIONS
151/ 191
13.5.2. 12-
PHASE CONNECTION
For >500kW drives, a
12-pulse rectifier is normally used. This suppresses the lowest harmonic current in the
supply line.
A 12-pulse inductance suppresses 5th and 7th harmonics; harmonics left are the 11th and the 13th, followed by
the 23th, the 25th and so on, with their relevant low levels. The supply current shape is very similar to a
sinusoid.
In that case, a dedicated transformer is needed, along with a specific interphase inductance for current balance
and an additional diode bridge installed outside the inverter (two supply modules are needed for modular
inverters).
Figure 73: Lay-out of a 12-phase connection.