Mutual Inductance Model of the Mechanical Stress Sensitivity of A Power Transformer’s Functional Parameters

The mutual inductance model enables testing of the behavior of power transformers under different operation conditions, especially under the environmental influences on the transformer’s core. This paper presents the results of an investigation of the stress dependence of the magnetic relative permeability of a power transformer. It was observed that under tensile mechanical stresses up to 98 MPa applied to the core, the transformer input current amplitude increases by almost 67%, whereas the transformer’s reactive power increases by 53%. In industrial systems, such changes can potentially lead to unwanted power system shutdowns due to overloading. This effect should be considered during the development of critical power systems.