OnLine Power Power Wave 4 - Manual (Page 21)

6005-145 Rev. A 1-10
1.4. Inverter
The inverter is composed of IGBT, inductor, capacitor, snubber, control circuitry
and protection circuitry. The inverter converts the DC power from the DC bus to
AC power to supply the output load. The ELI uses IGBT technology which
switches at frequencies beyond the audible range, therefore producing no
audible noise.
The ELI uses voltage regulation circuitry to limit the voltage variation within
1%. Special compensation circuitry is added to eliminate the output distortion.
Every component is oversized to accept the wide DC input range (from 285 to
420VDC), so that the output waveform remains sinusoidal throughout the range.
With the aid of dynamic feedback loop the inverter will keep a sine waveform
even under non-linear load.
An independent inverter is used for each phase. Although it is more expensive,
each inverter has its independent feedback, so that the voltage is unaffected
when load is added to the adjacent phase, producing excellent voltage regulation
under 100% unbalanced load.
The IGBT is operated in its optimal condition to obtain best efficiency, so as to
minimize the power cost of the user.
DC+
DC-
AC
AC
IGBT INVERTER