Upgrade of a paper mill power distribution system

An electric utility capacity increase from 50 to 100 MVA was implemented in a large Kraft paper mill in the USA. All existing plant 15 kV switchgear and controls were replaced and a new tie line constructed during a nine-month period prior to the utility increase. Electrical and process control rooms were built to house new switchgear and computer control equipment. All installation work was done during outages scheduled for other plant objectives. The new switchgear installed consists of 42 cells of 1000 MVA class equipment. The control system includes operator workstations, supervisory PLC, and remote I/O racks. Breaker control, metering, and load shedding functions are performed by the control system.