The VAU combined transformer merges the design features of the AGU current transformer and the VPU inductive voltage transformer. As such, it retains all the operational advantages of both transformer types. The open-core concept provides several operational advantages over conventional products. These include immunity to ferroresonance, explosion-proof construction, and robust resistance to very fast transient overvoltages. A key feature is its single insulation system for both transformer sections, which enhances safety and eliminates risks associated with primary insulation failures. Available with rated voltages from 72.5 kV to 550 kV, rated currents up to 6000 A, and short-time withstand currents of up to 100 kA (250 kA dynamic), they meet the highest industry standards. From its inception in 1994, KONČAR has established a trusted global presence, with over 9,000 units currently in operation worldwide.