Effect of electromagnetic shielding on the forces acting between conductors of three phase lines

When designing rotating electrical machines, transformer, and other electrical equipment for high power, it is necessary to resist the forces between the conductors carrying heavy currents. The paper deals with the magnetic shielding, which can reduce these forces. It presents a mathematical model of the magnetic field in the area of three parallel conductors of three‑phase supply. Based on the numerical solution the Lorentz force per unit length of conductors has been determined. The calculation of eddy current losses in the shielding jacket has been performed. The computational algorithm is illustrated with numerical examples. The general rules for a reliable design of shielding have been developed.