Tubular busbars are hollow, lighter in weight, and help improve cooling in high-current systems. In this paper on the basis of the electromagnetic field theory, the magnetic induction and flux linkages outside and inside tubular conductors are obtained from the Ampere Loop Theorem, and then the formulas to calculate approximately the reactance of tubular busbars with a three-phase parallel. A busbar is a metal bar, usually made of copper or aluminum, that carries electricity inside switchgear. It connects the incoming power to circuit breakers and outgoing circuits, helping power flow smoothly and evenly. Proper size. In electrical power distribution, a busbar is a thick strip or bar of copper or aluminum that conducts electricity within a switchboard, distribution board, substation, or other electrical apparatus. Busbars are used to carry very large currents or to distribute current to multiple devices within. Understanding switchgear's basic design and power distribution. Learning about the functions of double busbars. Equipment. Readers will learn about material selection, structural categorization, and practical applications of busbars in modern electrical engineering.