Assessment of the Influence of Magnetron Sputtered Coatings on the Electrodynamic Forces of Current-Carrying Busbars

In current-carrying parts of electrical apparatus, under certain conditions, large currents are transferred, which also define large electrodynamic forces striving to distort the current contours. The most severe is the short-circuit regime where the electrodynamic forces are proportional to the square of the short-circuit breaking current. As a result of their action the temperature of the elements increases, the mechanical strength decreases and a very heavy mechanical load regime is formed. This also determines the increased requirements for the materials for current-carrying busbars. Interesting from a practical point of view is the question of how a given coating affects the magnitude of the electrodynamic force. The use of protective coatings on heterogeneous materials can result both in the modification of the surface layer material which enhances the performance of the workpiece and in the formation of some new composite materials having both high strength and sufficient plasticity as well as increased wear and corrosion resistance. This leads to improvement of some of the operating parameters in the contact area of the current-carrying busbars. It is also important to assess the influence of the coatings on the magnitude of the electrodynamic force, which is also the subject of this research.