Diode bridge T-type LC reactor as transformer inrush current limiter

Abstract

An improvement inrush current limiter (ICL) is presented to form a highly effective inrush filter which further reduce the inrush current peaks and ripple voltage. The proposed ICL is constructed using a diode bridge and T-type LC reactor consisting of two inductors and one capacitor. The proposed ICL is connected at each phase of the primary winding of three phase transformer. The line current is rectified by the diode bridge and the increase in inrush current is limited by the T-type LC reactor. The proposed ICL is effective in reducing the peak inrush current by 80% more compared to single inductor type reactor. The potential of resonance take place in T-type reactor is completely avoided since the LC filter resonant frequency is very low while the lowest frequency the LC filter will ever see is well above is resonant point. The proposed ICL is numerically tested using simulation package PSCAD.