Upgrading power system protection to improve safety, monitoring, Protection, and control

One large Midwestern paper mill is resolving an arc-flash hazard (AFH) problem by installing microprocessor-based (muP) bus differential protection on medium-voltage switchgear and selectively replacing electromechanical (EM) overcurrent relays with muP relays. In addition to providing critical bus differential protection, the muP relays will provide analog and digital communications for operator monitoring and control via the power plant data and control system (DCS) and will ultimately be used as the backbone to replace an aging hardwired load-shedding system.