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Projects: Projects for Investigator
Reference Number	NIA_SHET_0014
Title	Partial Discharge Monitoring to Reduce Safety Criticality
Status	Completed
Energy Categories	Other Power and Storage Technologies(Electricity transmission and distribution) 100%;
Research Types	Applied Research and Development 100%
Science and Technology Fields	ENGINEERING AND TECHNOLOGY (Electrical and Electronic Engineering) 100%
UKERC Cross Cutting Characterisation	Not Cross-cutting 100%
Principal Investigator	Project Contact No email address given Scottish Hydro Electric Power Distribution plc (SHEPD)
Award Type	Network Innovation Allowance
Funding Source	Ofgem
Start Date	01 January 2015
End Date	01 November 2018
Duration	46 months
Total Grant Value	£1,300,000
Industrial Sectors	Power
Region	Scotland
Programme	Network Innovation Allowance
Investigators	Principal Investigator	Project Contact , Scottish Hydro Electric Power Distribution plc (SHEPD) (100.000%)
Web Site	http://www.smarternetworks.org/project/NIA_SHET_0014
Objectives	The overall objective of the project is to identify an economic solution to reducing asset criticality. This will be achieved through the following activities: ; Deployment of a continuous PD monitoring system at selected substations and monitoring the systems for at least 18 months to identify and understand excursions from expected levels of PD through all ambient and operational conditions; Delivery of tools for simplifying output PD data interpretation and compilation of suitable procedures for actions in event of alarms; Review of technical confidence and effectiveness of the trial systems with other approaches to reduce asset criticality. The project will be considered a success if it can determine the viability of continuous PD monitoring as a tool for management of safety critical assets on the network.
Abstract	Transmission Owners in GB have a common methodology for prioritising asset replacement. The methodology requires a risk based approach from the combination of an assessment of asset health and assessment of asset criticality. Criticality is defined as having three elements, safety criticality, environmental criticality and system criticality. Overall criticality is taken as the highest of the three elements. Plant such as circuit breakers which are in a substation located in a public place end up with a high safety criticality score i.e. a disruptive failure is likely to send shards of porcelain into the street / playing field / etc which could result in serious harm or even fatality. The current criteria which define safety criticality are only the location and impact of failure of an asset, neither of which can be changed without relocation. The result is that plant in such locations always appears high up on the list of asset replacement priorities, regardless of the condition of the plant. We are therefore seeking ways to reduce the criticality score of assets. Various options exist including : ; Construction of solid barriers; which have planning consent issues and block views into substations with increased likelihood of theft and vandalism. ; Replacement of plant and equipment with different failure mechanisms such as dry type transformers or composite bushings. This is an expensive option, especially where equipment is in otherwise good condition. ; Reduction of the likelihood of disruptive failure by continuous monitoring and proactive intervention. This project will evaluate the last option as a means of improving asset criticality indices by assessing the ease with which continuous partial discharge (PD) monitoring can be integrated with internal Supervisory Control and Data Acquisition (SCADA) systems. According to one of UK’s experts in PD, around 85% of all high voltage disruptive equipment failures are due to PD activity. If PD can be detected timeously through continuous monitoring then there can be early intervention to avert unexpected, often catastrophic, failure in service. PD detection principles in PD monitoring systems are largely understood. There have already been some trials in SHE Transmission as well as other networks which were aimed at understanding the range of PD detection technologies available and their effectiveness. These trials have demonstrated that PD detection techniques are now largely mature. However, use of permanent online PD systems in business as usual (BAU) in network asset monitoring is still not standard practice since interpreting and obtaining actionable information from any such detection is quite difficult and requires specialist knowledge. Currently, most PD monitoring is done as part of routine equipment inspection using handheld or mobile systems. Numerous variables including factors such as ambient conditions, background noise effects and frequency of inspections can impact the integrity of the inspection results thereby causing either hesitation or disproportionate response to PD detected this way, a situation which creates a conundrum for decision makers. As a result, conclusive presence of PD is usually only confirmed on the basis of consistent trends observed over a period of time. One of the ways to obtain such trends and also improve data resolution is to install temporary online PD monitoring systems on affected plant for specified periods depending on the perceived gravity of the problem. Typically, these temporary installations report their data to servers belonging to suppliers of the technology in use who have the expertise to interpret it and raise alerts. The biggest downside to this method is that should events evolve fast, there is high likelihood of equipment failing during the intervening period, a situation that is unacceptable when monitoring safety critical equipment. This project aims to start addressing the limitations of routine interspersed PD inspections of equipment and also the inherent delays due to reliance on third party alerts for responding to PD issues arising from temporary online PD installations. If successful, the method can then be adopted in monitoring assets with high safety criticality to enable earlier intervention. Although this intervention may not be necessary in every case, it is a precaution that is justified for safety reasons and still more cost-effective than alternatives. This is a technical method to continuously monitor critical assets for PD and integrate the installed measurement sensors with SHE Transmission’s SCADA in order for PD event data to be collected, stored, analysed and to enable PD interpretation to become part of routine internal control room activities. At least two PD monitoring technologies based on different detection principles and from independent suppliers will be installed at each of at least two sites identified as either having high safety criticality or having the requisite conditions to enable adequate learning about the integration of PD detection with SCADA systems*. This is necessary to ensure that the most viable PD monitoring solution or combinations thereof are established at the end of the project for potential rollout. An effective way of integrating PD data from the installed trial systems with existing SCADA infrastructure will be established. This will involve providing tools for making PD data and the user interface on which it is presented more intuitive to enable operational staff to interpret it more accurately without the need for intensive expertise. This knowledge will enable formulation of standard procedures that can be used by asset management staff to make appropriate decisions. After installation and commissioning, a period of close monitoring will follow for a period of at least 18 months. All data from installed PD systems will be collected and stored for retrieval and regular analysis. During that period, experts independent from the PD monitoring systems suppliers will provide evaluation and validation of the systems. The results from the trial will be used to inform an assessment of the viability of this method to reduce the cost of managing safety critical assets. At the end of the project, the trial installations will be assessed for ongoing use as business as usual. *29/09/2015: The main focus of this project is to demonstrate effective integration of PD detection with SCADA. The sites nominated for the trial have no known history of PD but have been chosen on the basis of safety criticality to ensure that if real PD should commence in the future there will already be a system in place to mitigate the potential impact. To complete the evaluation and validation of the trial systems, simulated PD signals will have to be used. As part of routine mobile inspections, a site has been identified where there is some evidence of PD activity. This presents a potential learning opportunity to test the integration of this real PD data with SCADA as part of this trial. A change in methodology is proposed to include monitoring the relevant part of this site. Under current practice, this monitoring would be temporary and the data produced would go to the monitoring equipment suppliers who would provide alarms should things appear to escalate. Under this project, this data will be retained internally and will form part of the analyses proposed in the rest of this project.Note : Project Documents may be available via the ENA Smarter Networks Portal using the Website link above
Publications	(none)
Final Report	(none)
Added to Database	17/09/18