Authors: N.F. Karnaukhov, M.N. Filimonov, D.A. Smyatsky

Title of the article: Modeling of dry friction link of the production mechanism with a frequency drive in the low speed zone

Year: 2018, Issue: 2, Pages: 145-154

Branch of knowledge: Electrical engineering

Index UDK: 621.865.8-83

DOI: 10.26730/1999-4125-2018-2-145-154

Abstract: The article presents the results of theoretical and experimental studies of the dry friction forces effect on the industrial mechanism motion characteristics in the low-speed zone, it provides substantiations for the use of an autonomous voltage inverter bimodal control and gives recommendations for expanding the application area of production mechanisms frequency-controlled electric drives. The random nature of change of the frictional forces between the moving parts of industrial mechanism joints during the induction motor start-up and braking makes it difficult to implement a programmable braking and reduces the accuracy of the industrial mechanism operating device positioning. Pulsating torques on the induction motor rotor during start-up and braking caused by the stator current harmonics together with the friction torques in the contacting zones of the industrial mechanism moving links and the drop guides considerably worsen the real dynamics of the output link movement and increase the probability of the forced oscillations occurrence. To improve the quality of motion of the output link during the asynchronous motor braking mode (before stopping), the authors proposed a two-mode autonomous voltage inverter control that allows to adjust programmatically the stator current harmonics amplitudes by stepwise changing the carrier frequency and introducing an m-fold "submodulation". The performed researches made it possible to reveal the effect of the "microvibration" of an asynchronous motor rotor on the change of the "effective" friction factor value of the moving links in the industrial mechanism drop guides. The adjusting of the "effective" friction factor "conditionally reduces" the frictional force, decreases the drive power to overcome the frictional forces of the links during start-up, and improves the uniformity of their movement in the drop guides during braking. The use of an autonomous voltage inverter with bimodal control will allow to improve the formation of individual mechanical characteristics of a frequency-controlled electric drive. In addition, it will allow to expand the implementation area of the frequency-controlled electric drives in technological equipment, multi-link mechanisms of automated industry (balanced manipulators) which operate in the "low and creeping speeds" zone.

Key words: moving link industrial mechanism oscillations amplitude induction motor start-up induction motor braking autonomous voltage inverter summary voltage harmonic components factor start-up torque low speed zone

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