System Investigation of High Temperature Superconducting Self-limiting Transformer

A high temperature superconducting (HTS) self-limiting transformer (SLT) is a combination of a transformer and a fault current limiter in one unit. We designed and built a small-size self-limiting transformer. This device has two or more copper windings and one or more HTS ring(s) placed on a separate limb to operate when short circuit currents occur. We have investigated several constructions on the experimental device, viz. iron core with two or more limbs. The self-limiting transformer was connected to various loads: resistive, capacitive and inductive. The effects of various loads were studied, which helps fit the parameters of HTS SLT to the electric power network. A calculation about a real power network in order to realize the requirement for the SLT is presented.