In view of large DC magnetic bias evaluation deviation of AC power network transformers

the influence of transient power transfer control strategy of DC system is considered in this paper and the DC magnetic bias simulation analysis model in the adjustment of operation mode of ±1 100 kV Guquan DC grounding pole is set up through the field-path coupling method. The change of surface potential in different soil models and different distances from the ground electrode are calculated during the adjustment of operation mode of grounding pole and the response of transformer excitation characteristics is evaluated. The results show that the adjustment process of the operation mode of the DC grounding pole has a great influence on the adjacent deep soil with high resistivity

and the DC magnetic bias is the most serious. With the increase of distance from the ground pole

the influence of the ground potential on the operation mode of the ground pole decreases which

in case of distance of more than 10 km

can be basically ignored. The simulation result in this paper provides a kind of DC magnetic bias evaluation method in accordance with the simulation result

which provides a reference for DC magnetic bias evaluation of transformer during the operation mode adjustment of DC grounding pole.