Implementation of a Conveyor Belt Speed Control System Using VFDs for a Cement Plant in Ogun State

Cement manufacturing in Ogun State, South West Nigeria, involves extensive conveyor systems for raw material transport, clinker transfer, and finished product packaging that consume significant electrical energy and require reliable speed regulation to match production process requirements. This study presents the implementation of a variable frequency drive-based conveyor belt speed control system at a clinker transport conveyor line at a cement plant in Ewekoro, covering five conveyor belt sections of between 80 and 150 metres in length. ABB ACS880 industrial drives were installed for each conveyor section motor, programmed with process-adaptive speed reference profiles derived from clinker throughput demand signals from the kiln supervisory system. Soft-start ramp profiles were configured to reduce mechanical shock at belt start-up. Load feedback torque monitoring was implemented to detect belt overloading and blockage conditions. Post-implementation performance monitoring over five months showed a 27 percent reduction in aggregate conveyor motor energy consumption compared to the fixed-speed baseline period. Belt splice failure frequency reduced from an average of 2.1 events per month to 0.4 events per month, attributed to the elimination of high-inertia direct-on-line starting. Conveyor availability improved from 91.3 percent to 97.6 percent over the monitoring period. The study documents the commissioning methodology, including load testing and drive parameter optimization procedures specific to long-belt conveyor applications in tropical cement plant environments. Keywords: conveyor speed control, variable frequency drive, cement manufacturing, energy efficiency, Ogun State