Advanced Inrush Current Mitigation ‎Techniques for Microprocessor-Less High ‎Power AC/DC/DC Synch-Buck ‎Converters: A Start-up Perspective

This paper investigates the starting current of an AC/DC/DC converter, consisting of a ‎three-phase diode bridge rectifier and a synchronous buck converter. The use of ‎microprocessors in such converters increases the total cost and also reduces reliability due ‎to EMI phenomena. For this reason, by removing the microprocessor, a start-up plan ‎including a limiting starting resistor and then soft starting the switching module is proposed ‎in this paper. By modeling the system under different operating modes, a solution is ‎presented to minimize the circuit startup period, which includes minimizing the bypass time ‎of the startup resistor and reducing the switching soft startup period as possible. The ‎proposed method has been implemented on a ۱۵-kW converter feeding from a three-phase ‎‎۳۸۰ V power grid and provides up to ۳۰۰ Vdc/۵۰ Adc to supply an electroplating pool. The ‎results show that the sequential startup procedure, including using a ۵۰ ohm/۱۵۰۰ w resistor ‎for ۳ seconds, and then bypassing it, then starting soft switching after half a second and ‎during ۱.۵ s, can move this circuit to a steady state in ۵ seconds, keeping current in all parts ‎below half rated current.‎

Keywords:

Synchronous Buck Converter , ‎ Energization , ‎ Soft Start-up , ‎ Inrush current limiting.‎