Authors: V.M. Zavyalov, E.A. Dubkov, I.Yu. Semykina, V.V. Kolodyazhny

Title of the article: On the issue of ignition risk evaluation from the high-frequency alternating magnetic field in an explosive gas-and-dust atmosphere

Year: 2023, Issue: 2, Pages: 3-11

Branch of knowledge: 09.05.03 Electrotechnical complexes and systems

Index UDK: 622.6:629.423.32

DOI: 10.26730/1816-4528-2023-2-3-11

Abstract: Wireless battery chargers are able to reduce operating costs and the battery charging duration for mining electric vehicles. Implementing such systems requires special charging sites, where a high-frequency alternating magnetic field is generated to transmit energy into the mining electric vehicle battery. It should be noted, if the equipment installed on the charging site as well as on the mining electric vehicle can be protected by explosion proofing means, the area of electromagnetic interaction will be located directly in explosive gas-and-dust atmosphere being a potential ignition source. This article evaluates the conditions under which the ignition risk can be neglectable. The analysis reveals that if there are no foreign objects in the area of elec-tromagnetic interaction, the high-frequency magnetic field itself is not a heat source, but when a metal object appears there, it is inductively heated. The resulting temperature of the metal object is determined by the energy balance between the absorbed magnetic field energy and the dissipated thermal energy. The article gives the dependences that relate the absorbed magnetic field power with the field parameters and the overall dimensions of a metal object, as well as the dissipated thermal power with the object overall and thermal diffusivity. In the final part of the article, the equations are obtained that make it possible to calculate the limiting magnetic induction. If magnetic induction in the area of electromagnetic interaction is less than the limiting value, it guarantees that the maximum surface temperature of the metal object will not exceed the limiting temperature, and therefore there is no probability of an explosion.

Key words: wireless battery charging mining electric vehicles explosion safety high-frequency magnetic field induction heating thermal diffusivity magnetic induction

Receiving date: 03.03.2023

Approval date: 15.04.2023

Publication date: 17.05.2023

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