Impact of voltage sags on rotary press and a method to prevent paper break during sags and brownout—A case study

This paper describes how voltage sags impact the operation of a newspaper printing machine. Rotary printing machines have offset printing cylinders and chain of rubber rollers running through variable speed synchronous motors. The servo drives controlling these motors are severely impacted by voltage fluctuations in the grid power supply. In the present case study the analysis is carried out for the impact of voltage sags and transients on a rotary printing press. A logical solution is developed to reduce the machine downtime resulting due to these power quality issues. The concept, methodology, circuit diagrams and result of this solution are presented in this paper.