PROJECT TITLE :

Efficient resonant-type transformer inrush current limiter

ABSTRACT :

This study presents a new structure of a solid-state inrush current limiter (SSICL) to mitigate the inrush current of transformers. The proposed SSICL encompasses a series??parallel resonant structure that's shaped by 2 resonant circuits tuned at the provision frequency. During the energisation of transformers, the SSICL offers very high impedance by the parallel resonant circuit; thus inrush current is dramatically reduced. Below traditional conditions, an SSICL exhibits very low impedance through the series resonant circuit. By energising the transformer, an auto-triggered silicon-controlled rectifier (SCR) circuit inserts the parallel resonance circuit within the transformer input terminals. As well as the self-controlling capability, the proposed SSICL can be triggered by an external command. This effective remedy assures the right operation of the transformer protection system. So with a very easy structure, it has a fast and reliable performance in addition to full management capability. A prototype single-part SSICL is simulated by electro-magnetic transient program (EMTP) and tested. The simulation and experimental results show that the proposed SSICL significantly reduces the inrush current during the energisation method of the transformer.