Abstract: In view of the deficiency of deformation monitoring technology in transformer substation, a 220 kV substation in Zhaotong is selected to carry out research on deformation monitoring technology under strong electromagnetic condition. The field monitoring is performed by Beidou satellite positioning technology, laser ranging technology, inclinometer and rain gauge. The research results are described as follows: (1) Strong electromagnetic interference has a serious impact on the monitoring accuracy of global navigation satellite system (GNSS). If the influence of electromagnetic interference cannot be effectively reduced, the results of GNSS displacement monitoring cannot be used for monitoring and analysis of substation foundation deformation. (2) Based on the detection of substation electromagnetic field intensity, a monitoring point design and implementation method to improve the settlement monitoring accuracy of substation GNSS under strong electromagnetic field environment is proposed. The monitoring points with electronic components are arranged at the places with relatively weak electromagnetic field intensity to reduce electromagnetic interference and monitoring error. (3) For the first time, the low-cost and high-precision laser ranging technology is introduced into the substation horizontal displacement monitoring and successfully implemented. The research provides a new technical means for deformation monitoring of substation on soft foundation in mountainous area, which can improve the quality and management level of substation project.

Key words: transformer substation, electromagnetic interference, deformation monitoring, Beidou positioning technology, laser ranging technology