地铁中存在的杂散电流会对地表电位分布产生影响，而如果周边存在电力变压器时，变压器中流过的直 流电流会造成变压器发生直流偏磁，然而，目前关于地铁地表电位分布对周边变压器直流偏磁影响研究较少， 为此考虑了列车上下行 4 种不同运行状况，搭建地铁地表电位仿真模型，并计算相应情况下变压器励磁电流畸 变率，得出上下行列车同时出站时，对变压器直流偏磁影响最严重的结论，为预防电力变压器发生直流偏磁提 供理论依据。

With the rapid development of economic construction and the continuous expansion of urban scale, to solve the contradiction between the supply and demand of urban transportation, China has developed a robust urban rail transit construction in recent years, forming a complex urban rail transit network in large cities. Several cases have shown that stray current in the metro affects the surface potential distribution, and if there is a power transformer nearby, the DC current flowing through the transformer causes the transformer to be DC biased. However, regarding the current situation of the Metro surface potential distribution, there is limited research on the influence of DC bias of surrounding transformers. For this reason, this study considers four different operating conditions of up and down trains, builds a metro surface potential simulation model, calculates the transformer excitation current distortion rate under corresponding conditions, and obtains the up and down direction when the trains leave the station at the same time. The conclusion that has the most serious impact on the DC bias of the transformer provides a theoretical basis for preventing the DC bias of the power transformer.

TP391.9；U228.1