Interlayer Insulation

Interlayer insulation is a critical component in medium voltage current transformer core assemblies, consisting of thin insulating material layers inserted between stacked magnetic steel laminations. Its primary function is to electrically isolate individual laminations, thereby minimizing eddy current circulation within the core during alternating current operation. This insulation reduces core heating, improves transformer efficiency by lowering no-load losses, and enhances magnetic performance by maintaining proper flux distribution. The component must withstand thermal cycling, mechanical compression forces, and maintain dielectric strength throughout the transformer's operational lifespan.

Works by creating electrical barriers between conductive magnetic steel laminations in transformer cores. When alternating magnetic flux passes through the core, it induces circulating currents (eddy currents) within the conductive laminations. The insulating layers interrupt these current paths, forcing eddy currents to circulate within individual laminations only, dramatically reducing their magnitude and associated I²R heating losses. This principle follows Faraday's law of electromagnetic induction and utilizes high-resistance dielectric materials to block inter-lamination current flow while allowing magnetic flux to pass through with minimal reluctance.