Projects: Projects for Investigator UKERC Home UKERC Energy Data Centre Projects Choose Investigator All Projects involving NIA_NGET0012
Reference Number	NIA_NGET0012
Title	Induced voltages and currents on transmission overhead lines under NSI 4 working practices
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 National Grid Electricity Transmission
Award Type	Network Innovation Allowance
Funding Source	Ofgem
Start Date	01 February 2014
End Date	01 June 2016
Duration	28 months
Total Grant Value	£135,000
Industrial Sectors	Power
Region	London
Programme	Network Innovation Allowance
Investigators	Principal Investigator	Project Contact , National Grid Electricity Transmission (100.000%)
Web Site	http://www.smarternetworks.org/project/NIA_NGET0012
Objectives	The key objective of this project is to establish working practice requirements based on the application of innovative modelling techniques developed by Cardiff University. Production of a Induced Voltages and Currents progress report Production of a Safety Assessment progress report Production of a final report on Induced Currents and Voltages and safety practices on OHL transmission lines
Abstract	Previous detailed calculations carried out by National Grid, led to the currently adopted drain earth requirements being applied to National Grid transmission towers and specified in the National Safety Instruction Guidance document NSI 4. Based on questions and feedback from field engineers and maintenance staff, the NSI 4 working group propose to reconsider some of the background assumptions and explore different approaches to re-assess maximum levels of induced currents and voltages which inform work practice on or near high voltage lines. Research The method that has been proposed for this project includes; Induced voltages and currents Calculate the maximum level of induced voltage (steady-state and switching transient) on a de-energised phase conductor of a 275kV and 400kV line when Drain Earths are applied at every 10th tower and with Primary Earths at both circuit ends. ALARP risk assessment Quantify the individual risk (IR) of electrocution, measured on the ALARP scale, when accessing terminal towers and taking into account missing or broken earth tapes between the substation main earth grid and the tower. The IR will be determined for scenarios such as climbing the tower to apply drain earths* and if a significant risk is found an evaluation will be made to determine whether the risk can be controlled to acceptable levels by limiting the time spent in the vicinity of the tower*. The IR will be calculated for both steady-state and fault (EPR) conditions.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	20/08/18