Research on Influence of Tidal Geoelectric Field on Geomagnetically Induced Current Calculation of Power Grid

At present, there is a huge error between the calculated value of the Geomagnetically Induced Current (GIC) and the measured value, which affects the implementation of GIC's protection work. In order to obtain the root cause of the error, combined with the formation mechanism of GIC and induced geoe-lectric field, it is found and proposed that the Tidal Geoelectrical Field (TGF) is an important influence factor that causes the continuous change of GIC. The feasibility solution method of TGF acting on the power grid is given, and the mathematical expression of GIC in the calculation of the geocentric coordinate system is derived. Finally, taking the Lanzhou area of Gansu as the research ob-ject, the GIC level of the power grid caused by TGF was calculated by estab-lishing a local grid DC equivalent model and using numerical simulation meth-ods. Compared with the calculation results of other literatures in the same area, the maximum GIC value generated under the action of TGF accounts for 44.9% of the calculated value of GIC during the geomagnetic storm. Therefore, the subsequent analysis and analysis of GIC must consider the influence of TGF.