OPTI-UPS DS160KD33 - Manual (Page 13)

1-9
PHASE SHIFT
TRANSFORMER
AC
INPUT
RECTIFIER
BREAKER INDUCTOR
SCR
DC
OUTPUT
CAPACITOR
SCR
12-PULSE FULL CONTROL RECTIFIER
In order to further improve the power factor and reduce harmonic current drawn by
the rectifier, our UPS from 100KVA and above use the 12-pulse full controlled
rectifier. The total current harmonic current can be reduced to around 15%, and
power factor is improved to over 0.8. A phase shift transformer is added to achieve
the performance. The input inductor is retained too to obtain the best result. Although
the cost is higher, it is most reliable and rugged topology. Users need not to increase
the input breaker and cable, input KVA and harmonic current drawn is minimized to
fulfill the worldwide energy saving requirements.
The harmonic current can be further lowered by adding harmonic filters (install upon
request). The total harmonic current will be around 9%.
Another alternative method to reduce the harmonic current (especially for very large
KVA UPS) is to employ 18-pulse full controlled rectifier. The total harmonic current
will be around 7%.
1.4. Inverter
DC+
AC
AC
DC-
IGBT INVERTER