Analysis of factors affecting the inrush current in converter transformers

No-load commissioning of the converter transformer is prone to generating the inrush current, and the larger inrush current poses a greater threat to the DC transmission system. It is important to analyse the factors that influence inrush current to ensure the safe and stable operation of the DC transmission system. This paper first analyses the generation mechanism of the inrush current of the converter transformer from the perspective of magnetic linkage. Subsequently, factors affecting the inrush current are analyzed from aspects such as the AC system, converter transformer parameters, closing strategy, and residual flux, revealing the influence patterns of each factor on the inrush current, and combined with reference to the parameters of a ±800kV converter station to build the PSCAD model for verification.