As an important parameter to characterize the insulation state of oil-immersed current transformers

the oil-level can vary with operating conditions

external environments

and internal defects

etc. However

the correlation between the internal insulating oil and the structural response of the current transformer is still unclear

and it is challenging to differentiate between the normal micro- movements of the oil-level under multiple operating conditions and the early defect-induced variations. The paper proposes a three-dimensional numerical model of 220kV oil-immersed inverted current transformer and guides the correction of pressure compensation parameters of the model based on the measured h-P curve. Based on the simulation of fluid-thermal-structure interaction

the paper explores the internal temperature field distribution and structural deformation characteristics of current transformers under overload conditions

and the comparative verification is accomplished through the temperature rise test. The paper guarantees modeling accuracy based on dual experiments

and explores the steady-state oil-level characteristics of the current transformer under different ambient temperatures and load currents using this model

providing a theoretical basis for the precise recognition of the status of current transformers.