OnLine Power Battery Backup System - Manual (Page 14)

OLP
Three Phase UPS Systems
1. SYSTEM OVERVIEW
1-10
DC+
AC
AC
DC-
1.4. Inverter
IGBT INVERTER
The inverter is composed of IGBT, inductor, capacitor, snubber, control circuitry and
protection circuitry. The inverter converts the DC power from the DC link to AC
power to supply the output load. The UPS uses IGBT technology which switches at
frequencies beyond the audible range, therefore ensuring quiet operation.
The UPS uses voltage regulation circuitry to limit the voltage variation within 1%.
Custom compensation circuitry, for the dynamic loads and medical imaging power
signature is added to decrease the generation of output distortion. Every component is
oversized to accept the wide DC input range (from 285 to 420VDC); providing the
power and support to keep the output waveform sinusoidal throughout the range.
With the aid of the dynamic feedback loop the inverter maintains a sine waveform
throughout high current demands and imaging procedures.
An independent inverter and feedback control is used for each phase. The
independent control assures the voltage is unaffected when load is added to the
adjacent phase; producing excellent line to line voltage regulation under 100%
unbalanced load.
The IGBT is always operated in its optimal condition to obtain best efficiency thus
minimizing the overall cost of operation.