High performance rectifier with active filter assisted by electrical double layer capacitor

In this paper, high performance diode rectifier with active filter (AF) connected in parallel. The AF suppresses harmonics and improves the input power factor. In order to feed constant power to loads, the rectifiers have to control DC link voltage. The AF can control the DC link voltage. However if the AF controls the DC link voltage, harmonics suppression function of the AF is reduced. So DC link voltage is controlled by step-up and step-down chopper control with the EDLC. Therefore main function of the AF is almost harmonics suppression. So the capacity of the AF can be reduced. Also if the DC link voltage is controlled by step-up and step-down chopper control with the EDLC, the energy efficiency of this system can be improved. This is because regenerative power of the loads charges the EDLC. Also in the power accelerative operation, the charged power in the EDLC is discharged to the loads.