Analysis of the impact of integrating high-sensitivity short-circuit protection devices on transformer protection

Abstract With the expansion of power grids, increasing short-circuit currents pose significant risks to the safety and stability of transformers. Traditional methods, such as impedance adjustment and series reactors, face limitations in control capability and economic feasibility, while the application of fault current limiters (FCL) offers a new solution. This paper takes the operational parameters of an existing 110 kV substation as a case study, constructing a simulation model to analyze the short-circuit current behavior under different operational modes with and without the installation of an FCL. The results are compared with protection settings, and the impact on relay protection coordination is assessed. The study verifies that the FCL enhances system stability without affecting the coordination of existing protection devices.