Increasing Long-Belt-Conveyor Availability by Using Fault-Resilient Medium-Voltage AC Drives

Belt conveyors constitute an efficient and economical way for minerals and heavy-load transportation from mines to their destination, serving vital process units whose success depends on continuous operation. To meet important operational requirements, modern high-capacity conveyor systems are equipped with medium-voltage variable-speed induction motor drives. The reliability and service continuity of such drives play a critical role in the entire conveyor availability. This paper proposes an alternative to significantly improve the availability of the conveyor systems by using fault-resilient medium-voltage ac drives. Based on recent studies and the authors´ experience, it is shown in this paper how the conveyor drive downtime can be dramatically reduced after an internal short circuit, keeping the overall cost to repair to a minimum and avoiding financial losses that can reach several million dollars.