A 15kV transformer is a static electrical device designed to transfer electrical energy between circuits through electromagnetic induction. The “15kV” designation typically refers to the primary voltage rating, meaning it is built to handle voltages up to 15,000 volts on the input side. These transformers are pivotal in stepping down voltage from medium-voltage distribution lines (often in the 15kV range) to lower voltages (like 480V or 240V) suitable for commercial and industrial facilities. Conversely, they are also used in step-up applications, which we will explore in detail.
Their construction is rugged, designed for either pole-mounting, pad-mounting (in a locked cabinet on the ground), or installation in a substation. They are filled with dielectric oil or dry-type insulation to manage heat dissipation and prevent electrical breakdown. The reliability of a 15kV transformer directly impacts the stability of the power supply for factories, data centers, hospitals, and large residential complexes.