Voltage-source inverter has a configuration where rate of change of voltage (dv/dt) in the inverter is limited by a large capacitor connected in parallel across the DC link. Current-source inverter has a configuration where rate of change of current (di/dt) in the inverter is limited by a large choke connected in series in the DC link.
The voltage-source inverter topology uses a diode rectifier to convert AC voltage to DC while current-source inverter topology user thyristors or Silicon Contrlled Rectifier (SCR) for the rectifier section. This is the reason why current source topology produces higher harmonics compared to voltage source topology. This is the reason why voltage-source are preferred to current-source. For large drives (above 20MW), current source is still preferred as it can operate in slightly leading power factor.
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