This invention relates to a method for calculating the residual
magnetism of a converter
transformer based on
inrush current, belonging to the field of power systems. Based on obtaining the deep saturation excitation characteristic curve of the converter
transformer, this method uses the per-unit value of the effective
inrush current generated by no-load closing at the peak
voltage of the converter
transformer as a parameter to calculate the theoretical per-unit value of
magnetic flux. Using the starting point for calculating the per-unit value of residual
magnetism, the ratio of the rated voltages of the primary and secondary sides of the converter transformer, and
a weighting constant, a superposition weighting formula for the residual
magnetism of the converter transformer and the rated
voltage magnetic flux is determined. Finally, the residual magnetism of the converter transformer core is calculated using the calculated per-unit value of the theoretical
magnetic flux corresponding to the
inrush current and the superposition weighting formula for the residual magnetism and the rated
voltage magnetic flux. The method proposed in this invention is simple to implement, highly operable, and has minimal
impact on the converter transformer, providing an effective
verification strategy for calculating the residual magnetism of converter transformers and evaluating the effect of residual magnetism
elimination.