Some aspects of bucket wheel excavators driving using PWM converter - Asynchronous motor

Abstract

Static converters are very important element in controlled drive systems. The development of the power semiconductor elements has revolutionized the field of electric power control and has permitted the improvement and the diversification of the electric energy converter. Loads with highly distorted current waveforms also have a very poor power factor; because of this, they use excessive power system capacity and could be a cause of overloading. The power supply from the Oltenia open pit coal mine machinery consists of electrical cables from 20/6 kV transformer station rigged with 4 or 6 MVA transformers counting 188 pieces, providing 1263, 3 MVA rated capacity. © Springer Science+Business Media B.V. 2010.