Quantitative Analysis of Small-sized Transformer No-load Closing Inrush Current Considering Leakage Inductance

The transformer is the main equipment of the grid system, however, the heavy and harmful inrush current may be generated when the transformer is switched on and the inrush current is random and difficult to quantify. This paper presents a method to calculate the maximum inrush current during switching on of the transformer, analyzes whether the leakage inductance can reduce the inrush current, and quantitatively calculates the inrush current whether the leakage inductance is considered. The modeling simulation and experimental waveforms can verify each other, and makes an error analysis. This method can be used as a reference for controlling the transformer closing inrush current.