The energy efficiency increasing of the system "Rock excavator – Power line" in conditions of the Ukrainian mining and ore enterprises

A large portion of rock excavators working in the quarries of Ukraine are equipped with a fivemachine system "generator - motor" [1]. In this system, during the start-up period, the primary synchronous motor is directly connected to the power supply system. This technical solution causes seven-fold starting currents, which create 49-fold electrodynamic forces, which leads to the rapid accumulation of fatigue damage in the windings of the synchronous machine and the power transmission line. Therefore, the existing technology imposes strict restrictions on the number of direct starts of the motor - no more than 3-4 times a day, which makes it possible to maintain the aggregate in a working condition.