Electrodynamics of Power Losses in the Devices of Inter-Substation Zones of AC Electric Traction Systems

Abstract

This article presents a new method for the estimation of active power losses based on a “field” approach, i.e., on the theory of the electromagnetic field and the theory of propagation of electromagnetic waves in a dielectric medium. Electromagnetic waves are assumed to transmit energy from the traction substation to electric rolling stock through the airspace of the inter-substation zone (i.e., not through the wires of the traction network) and meet electrically conductive surfaces on their way. The waves are partially reflected from the surfaces and partially penetrate them, thus creating thermal losses, the determination of which is the main task of this article. The analytical expressions for specific losses of active power are obtained by solving the system of Maxwell’s equations. Calculations of specific power losses in the catenary, rails, roofs, and bottoms of carriages and electric locomotives are performed. Power losses in carriages and electric locomotives are found to be at least 7%. A comparative assessment of the magnitude of total power losses of different types obtained by the “field” and “circuit” approaches is provided, which has established that “conditional” losses correspond to losses in rails, train carriages, and electric locomotives.