Increasing long belt-conveyors 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, they serve 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 for the entire conveyors availability. This work proposes a way to significantly improve the availability of the conveyor systems by using fault-resilient medium voltage AC drives. Based on recent studies and authors experience, it is shown in this paper how the drive conveyor 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.