Известия Томского политехнического университета: Инжиниринг георесурсов (Jun 2020)
INFLUENCE OF HIGH HARMONICS ON A FREQUENCY CONVERTER OPERATION IN UNDERGROUND MINING
Abstract
The relevance of the research is caused by the need to identify the causes of failure of the nodes and parts of the frequency converter, as well as the capacitor of the filter compensating device in the electric drive system of the skip hoist. The failure of this unit during the development of the protection algorithm leads to application of a safety brake to the lifting machine, which has a sufficiently large kinetic energy, which, in its turn, dissipates in the components and parts of the lifting machine, leading to a reduction in their service life. The aim of the research is to determine the degree of influence of higher harmonics in the power supply system of an underground mine on the elements of the frequency converter of the electric drive system of a skip hoist installation and propose methods to reduce them. Objects: frequency converter, electric drive system of a lifting installation, power supply system of an underground mine, other technological installations and their electric drive systems that affect the generation of higher harmonics. Methods: instrumental control of electric energy quality indicators in accordance with the requirements of GOST 32144-2013; mathematical processing and analysis of the results using the MathCAD software; computer simulation of the operation modes of the electric drive system in the MatLab environment. Results. The authors have given the characteristic of a skip hoist machine for a blind skip shaft and its electric drive system and analyzed the results of inspection of the electric drive system obtained both before and after putting the unit into commercial operation. The reasons for the failure of the filter compensating device are investigated, and the causes of failures in the operation of the frequency converter are analyzed. The authors drew the conclusions on the effect of higher harmonics on a frequency converter operation in an underground mine and proposed the measures to protect electrical equipment from higher harmonics and methods for their reduction.
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