Verification of frequency converter with small DC-link capacitor

Traditionally, large DC-link capacitors have been used in voltage source inverters. By using MPPF-type capacitor the line current harmonic content is improved and the unreliable electrolytic capacitor can be omitted. In this paper, the dynamic behavior of an inverter with small DC-link capacitor has been studied by simulations and laboratory tests. A new modulating principle, named differential space vector pulse width modulation (DSVPWM), can deal with heavily fluctuating DC-link voltage and produce correct voltage vector with high accuracy. The performance of the DSVPWM has been verified with simulations