On-line partial discharge condition monitoring of complete networks for the pulp and paper industry: Challenges and solutions explained through case studies

Outages within the paper industry lead to significant costs to operators. To reduce unplanned outage and losses condition monitoring (CM) techniques can be implemented to determine asset health and help target maintenance where it is most required. The challenges faced by the paper industry to implement condition based maintenance (CBM) on their medium voltage (MV) and high voltage (HV) networks and solutions for on-line partial discharge (OLPD) monitoring are due to the range and number of assets present and geographical spread coupled with problems of retrofitting the technology on pre-existing plants. The implementation of OLPD testing and/or monitoring can vary based on several factors: network topology, connected assets, switchboard type, owner budget and owner's desired local engineer involvement. This paper discusses different approaches to implementing an OLPD test program, ranging from simple handheld survey units to complete network monitoring. This paper focuses on case studies of the deployment of OLPD testing and monitoring solutions at several paper sites within the U.S. The case studies will present diagnostic testing of unshielded MV cable at one paper mill up to full permanent OLPD monitoring systems at two others.