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.