“Regenerative drives in the megawatt range for high performance downhill belt conveyors”

Downhill transport of ore from the mine to the beneficiation plant by means of belt conveyors introduces important advantages for the personnel and for the equipment. Furthermore, if the conveyor is equipped with a regenerative AC drive, the system generates an important amount of electrical energy for use in the process. This paper discusses the technical alternatives and the criteria used to select the solution with modern converter-inverter drives in the megawatt and medium voltage range. The considered drive alternatives are: (i) AC wound rotor induction motor drive with additional resistors, (ii) AC synchronous motor with cycloconverter, (iii) AC induction motor with current source inverter and (iv) induction motor with multilevel voltage source inverter. The study reveals that the use of a three-level active front end feeding a voltage source three-level inverter is the most appropriate alternative, considering the main technical criteria