Authors: E.K. Eshchin

Title of the article: Features of dynamic processes of self-propelled mining machines

Year: 2023, Issue: 3, Pages: 3-12

Branch of knowledge: 2.4.2. Electrotechnical complexes and systems (engineering)

Index UDK: 316.4.057.4, 621.313-57, 622-1/-9

DOI: 10.26730/1816-4528-2023-3-3-12

Abstract: The possibility of occurrence under certain conditions of the so-called "hidden oscillation" in the electromechanical systems of tunneling machines such as self-propelled mining machines located on an elastic base and receiving electrical energy through an extended cable network. Attention is drawn to the fact that by its impact on the mechanical transmission device (reducer) and the machine body, the mode of starting the asynchronous electric motor (IM) of the electric drive of the executive body by direct connection to the network is equivalent to the operation of a DC motor in the Sommerfeld experiment with an eccentrically located weight at its impact on the foundation of the engine, which in this experiment is also on an elastic foundation. In the considered version of the electric drive of the tunneling machines, the resulting changes in the position of the IM stator housing due to its mobility (base elasticity) can lead to changes in the absolute speed of rotation of the stator electromagnetic field, which can lead to a change in the instantaneous values of the IM electromagnetic torque and the occurrence of oscillations in the entire electromechanical system of the electric drive which can be classified as hidden (hidden oscillations). As an example, the starting mode of the electric drive of the executive body of the roadheader KSP-32 in a real power supply system is considered. Graphical results of calculations are given. It is concluded that in the electromechanical systems of self-propelled mining machines, under certain conditions during start, one can observe the manifestation of the Sommerfeld effect in the form of the occurrence of low-frequency hidden oscillations in the electromechanical system, accompanied by significant fluctuations in the AM power factor and, in particular, by oscillations in active and reactive power. The theoretical prediction of this phenomenon is difficult and can be detected by numerical simulation of the operating modes of the digital twin of the mining machine.

Key words: tunneling machine asynchronous electric motor electric drive hidden oscillations Sommerfeld effect

Receiving date: 21.03.2023

Approval date: 15.06.2023

Publication date: 11.07.2023

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