By analyzing the structure and regulating mode of 1 000 kV ultra-high voltage regulation and compensation transformer

a set configuration scheme of the transformer protection is put forward. By analyzing the misoperation wave data of the transformer

it is found that the transformer protection second harmonic content is less than the empirical value

and the intermittent angle is not obvious as well

these would cause the differential protection misoperation. Based on excitation inrush current characteristics of the transformer

a mixed inrush current identification scheme is proposed. By using real time digital simulation system

results verify that the mixed inrush current identification scheme is suitable for the regulation and compensation transformer protection configuration scheme.