Моделирование системы управления электроприводом подъема экскаватора ЭШ 20.90 при работе в тяжелых горнотехнических условиях

Abstract

Walking excavators (ESH) are the main mechanization means when developing coal fields in the regions of Siberia. The operational reliability and in-use performance of overburden dragline excavators determine the mining enterprises’ capacity. The previous studies show that a large percentage of the failures of the mechanical equipment used in opencast mining is connected with the draglines. Reduction of the dynamic load in the kinematic elements of the ESH 20.90 lifting drive increases the operational reliability of the excavators operating in arduous conditions. The statistical analysis has shown that most of the excavators’ breakdowns are connected with the failures of their traction and lifting mechanisms. Therefore, to increase the draglines’ reliability, it is necessary to limit the load on the kinematic elements of the mechanical structure in the periods of the year with a significant temperature gradient. For this purpose, a standard closed-loop control system of the lifting electric drive has been modelled. The modelling has shown an unacceptable level of the dynamic loads arising in the kinematic elements of the excavators operating at low temperatures. As a result, an advanced lifting drive control system for the ESH 20.90 excavator has been developed. The system allows to control the engine torque by the speed, and to stabilize the sustained power of the drive. The study has shown that the suggested system significantly reduces the dynamic stress in the mechanical elements and therefore, increases the excavator’s operational reliability. The application of the developed control system for the lifting drives of dragline excavators has been substantiated.