V/F Control-based VFD for Multi-motor Belt Conveyors

Abstract: In VFD-driven multi-motor belt conveyor systems, an important problem is how to balance powers outputted by all motors. In this paper, a V/F control-based VFD used for multi-motor belt conveyor systems is descried. The VFD works in master/salve control mode, controls active current of each motor in a closed-loop manner to adjust its output frequency. Output voltage of the VFD is controlled in V/F mode, ensuring a constant air gap flux in motors and ultimately balancing output powers of all motors. Successful application proves that V/F control-based VFD for multi-motor belt conveyors is both effective and practical. Key words: Multi-motor belt conveyor; V/F; power balance; VFD