The lack of a clear and consistent commercial approach to quantify and analyse the social and environmental impacts of network developments alongside the economic costs and benefits and illustrate their quantification in a transparent way has let to overreliance on subjective interpretation by TOs and external bodies including planning authorities and potential objectors. This, in turn, has lead to significant delays in projects while these impacts are debated, resulting in an increased cost to deliver infrastructure projects, borne by network customers.

An example of this would be the Beauly Denny line which was delayed for 3 years while a Public Enquiry was held of the potential impacts of the transmission line on the Scottish Highlands. An estimated cost of £81m was agreed with Ofgem to mitigate the 73 planning consent conditions identified in during the public enquiry; a cost to electricity consumers which could potentially be reduced in future projects from a refined assessment of the social and environmental impacts.

Key Activities

Develop a method and software model to quantify the contribution of Transmission projects to the wider economy from direct, indirect, and induced expenditure.

• Identify key drivers of value creation.
• Identify key opportunities for network operators where the level and type of stakeholder engagement can be improved to enhance the stakeholder experience.

This project aims to improve asset management capabilities in line with the Smart Grid principle, for example more intelligent monitoring of assets’ remaining life. Prognostics and Health Monitoring (PHM) is, broadly speaking, the science of analysing the operating and environmental parameters of a system and using those data points to predict the remaining useful life (RUL) of the system.

Initially, a literature review of the science of PHM will be conducted to identify optimal tools for determining asset health and forecasting RUL. Knowledge from the review will be applied in the development of a small scale condition monitoring and prognostics system for predicting the RUL of an electromagnetic relay with a failure history which appears to exhibit a correlation between life expectancy and the applied voltage.

Subsequently, an online oil condition monitoring and prognostics system prototype will be developed incorporating a dedicated intelligent sensor system with data handling and communication capability. Once tested in the lab and optimised, the prototype will be demonstrated on decommissioned transformers in SHE Transmission’s licence area.

Key Features

• Develop a small scale system for predicting the remaining useful life (RUL) of an electromagnetic relay.
• Identify optimal tools for determining asset health and forecasting RUL.
• Develop an online oil condition monitoring and prognostics system prototype incorporating a dedicated intelligent sensor system.
• Demonstrate the prototype on decommissioned transformers in SHE Transmission’s licence area.

This project will investigate the use of a modified SBB Emergency Restoration System (ERS) as a Lightweight Tower Crane (LTC) in the trial construction and dismantlement of transmission towers in SHE Transmission’s license area to establish if it is technically feasible, economical, minimises environmental impact, and mitigates safety issues inherent in existing construction methods.
A modified SBB ERS will be trialled as an LTC in the construction and dismantlement of an appropriate range of towers (may include 132kV, 275kV and/or 400kV) to establish if the method can achieve:

• Reduction of construction time and costs.
• Reduction of environmental impact by reducing need for temporary access roads.
• Mitigation of safety issues of concern in tower construction that uses Derricks.

Key Activities

• Determine the method’s viability to reduce construction time and associated costs.
• Understand the extent to which the method can reduce the need for temporary access roads and the level of potential environmental benefit from this.
• Establish a best practice, procedure or methodology for using the method in the construction of transmission towers.
• Investigate the range of tower designs to which the method would be applicable.

This project will install a CAT-1 Transmission Line Monitoring system on a SHE Transmission line and demonstrate whether it can enable dynamic line rating resulting in safe and cost-effective line operation close to its thermal rating.

This has the potential to achieve additional transmission line capacity without the need for physical line uprating, resulting in Capex and Opex savings.

The project will verify the correlation between practical observations and the theoretical model already established, and determine system planning required in case of wider adoption of the method.

Key Activities

• Investigate the ease of integration of CAT-1 proprietary software with SHE Transmission’s SCADA system.
• Evaluate levels of additional capacity achievable on the trial line through use of the installed CAT-1 equipment.
• Investigate the extent to which the technology can be applied without need for physical line uprating.
• Estimate potential Capex and Opex savings from use of dynamic ratings based on the data obtained.

The initial objective of the project is to have a fully developed, assembled and working intrascope probe system which has been both mechanically and functionally tested within a laboratory-based environment. Once this is complete the intrascope system will be put through field-based testing on a number of spare, non-operational primary and supergrid transformers. This field based testing will provide practical experience in operating the intrascope system and allow for refinements to be made to either software or hardware if required. The system operation will be verified through destructive testing of the internal transformer winding insulation.

Providing this is successful and SHE Transmission is confident in the intrascope system, an investigation of an operational transformer will be planned. SGT3 at Tealing Substation (S/S) has been chosen based on the historical problems associated with it and the age of the asset. The final aim of the project is to investigate SGT3 using the intrascope system to analyse and assess the condition of the internal insulation.

Key Activities

• Develop a prototype of the system and perform laboratory tests for functional, mechanical and optical performance.
• Test and demonstrate the prototype on out-of-service transformers and perform necessary refinements for testing on operational transformers.
• Test and demonstrate the prototype in the field on an operational transformer on the SHE Transmission network.

This project installed four cross arms on a de-energised transmission line over a two-year period, with monitoring equipment installed to monitor the mechanical performance of the cross arms and the weather conditions. Following this trial, two cross arms were installed on a custom built steel tower and connected to a transformer to test the electrical properties of the cross arm.

The success of this project has resulted in an additional project to install and test the Insulated Cross Arms on a live transmission tower – see NIA SHET 0007.

Key Activities

• Install Design and build prototypes for the uprating of 132KV tower lines.
• Install protoype 132KV models in a harsh weather environment test area – The Lecht.
• Install current L3 prototype models in a coastal trial site to evaluate the effects of salt and other pollutants on the insulation – St Fergus.

This project follows on from the successfully completed NIA SHET 0006 project. Insulated cross arms  have been installed on the towers of an operational 312kV circuit and will be monitored for a period of up to two years to evaluate their electrical and mechanical performance when used in a real live operational environment.

Key Activities

• Install Insulated Cross Arms on an operational 132kV tower line.
• Capture the learning of the installation methods.
• Monitor and evaluate the installed trial Insulated Cross Arms for both electrical and mechanical performance in order to establish their readiness for use in the real operational environment.

This project will develop a new method that will allow reproducible results for the distribution of nano scale fillers into polymeric insulation material. Scalability of the techniques will be demonstrated through the creation and testing of prototype full size bushings. To do this a new manufacturing method will be developed.

This new material may have potential to allow the reduction in size of insulators in HVDC systems by demonstrating enhanced insulation properties.

Key Activities

• Assess whether nanocomposites can be dispersed in polymeric insulation material in a reproducible fashion.
• Assess whether a new improved insulation material can be created and used to construct full size products such as bushings.

The overall objective of the project is to develop a design for a DC/DC converter which could subsequently (as part of a potential separate project) be developed further into a laboratory demonstration.

The design of a DC/DC converter will be optimised and integration with HVDC systems investigated.

Key Activities

• Design and develop the software models of high power DC/DC converter.
• Study DC/DC converters, DC hubs and their integration with HVDC systems.
• Optimise the design of a DC/DC converter.
• Produce conclusions and recommendations on the design of DC/DC converters and their use integrating HVDC systems.

The intention of this project is to leverage innovations (for example: ICAs and low-sag conductors) to design a new suite of transmission structures to exploit fully their potential.

The scope of the project will include the following:

• Identify the requirements and standards that govern transmission voltage of 275kV.
• Assess new structure design options, including the use of new materials, from a review of what is being built internationally, and other innovations.
• Develop designs for a small number of the structure options that show the most potential, and model prototypes for the most promising.
• Assess safety, health and environmental impact of the new design, and review the economic implications.

Key Activities

• Development of a suite of 275kV transmission structures including production of scaled
  models of the new design.
• Safety, health, environmental, and economic assessments sufficient to decide whether to deploy the new design as an alternative to traditional designs.

This project will build and verify simulation models of lightning strikes on lines where the towers have high footing resistances (applicable to steel-lattice towers at voltages of 132kV and above), and investigate the protection options to inform decisions on lightning protection approaches.

Key Activities

• Understand the behaviour of transmission lines under lightning strike conditions.
• Determine alternative techniques to provide lightning protection on transmission lines.
• Create recommendations for a lightning protection policy for transmission lines.

This project will conduct a study aimed at establishing the feasibility of installing a trial MCSR on the SHE Transmission network including considerations of location, performance specification, and relevant system data. Risk analysis of the technology and training, operation and maintenance requirements will be reported.

The outputs will provide a basis for deciding the viability of installing a trial MCSR on SHE Transmission’s operational network without compromising safety, health and the environment as enshrined in GB statutes.

Key Activities

• Establish the best location for installing a trial MCSR, its performance specification and the relevant system data for the chosen location.
• Complete a detailed design of MCSR with capability to be adapted for the functionality of an SVC and including all associated electrical and civil designs.
• Perform risk analysis of the technology.

Install an online trial of PD monitoring systems incorporating alternative technologies and suppliers at selected sites and integrate with SHE Transmissions SCADA system in order to collect, store and analyse output PD event data to establish if this can be used to improve the management of safety critical plant. Learning from this project will also be used for further work to incorporate PD failure precursors into control and protection schemes.

To find suitable alternative backfill materials, conduct TR tests in the lab and in close HV cable proximity in order to identify the material which is most technically suitable, environmentally friendly and cost-effective for use in peat land.

This project seeks to improve upon and overcome the limitations of the phase 1 design to allow for better access, physical range, positional control and visual imaging capability, whilst accepting any improvements that can also be made to spectroscopic measurements. The scope of the project is to have a fully refined, assembled and functional intrascope probe system which has been both mechanically and functionally proven within a laboratory-based environment and via field trials.
This will be achieved by making the following developments to the Intrascope toolkit:

• Implementing alternative articulation methods of the Intrascope for improved reach and control.
• Selecting an improved visual imaging camera and light source for long range visibility within a transformer.
• Redesign of the Intrascope delivery system in conjunction with the improved articulation to ease of deployment.On completion of field trials an inspection procedure will be created to determine the optimal inspection requirements and methods along with an effective way of storing and presenting findings from the inspection. Once the system has been assembled in a laboratory environment and gone through initial functional and mechanical testing, it will be trialled on a range of available transformers. Refinements will also be made to both the hardware and software based on the learning obtained from this test phase.

The Remote Asset INertial Monitoring and Alerting Network (RAINMAN) innovation project, once complete, will allow monitoring via a web-based server making it possible to pin-point the location of any unusual disturbances on the electricity network. This could mean quicker fault restoration following weather events, and even the detection of problems before they occur.

This project seeks to develop a prototype to evaluate the condition of the core of ACCC conductors. It will aim to gain an understanding of the effectiveness of the ACCC composite core inspection tool in evaluating the carbon core.

The aim of this project was the development of a passive fault level monitoring programme across six transmission substations providing good coverage of fault levels across the SHE Transmission system in the North of Scotland.

Line Inspections by Semi-Autonomous Systems (LISAS) this project will be the first time a highly autonomous robot will be used to inspect the electricity networks in the United Kingdom. LISAS will trial a robot system capable of making its own decisions without human control. It will navigate its own route as it moves form overhead line to overhead line, seamlessly navigating from steel tower to steel tower, as it captures critical asset data to inform reinforcement and maintenance requirements.

Partial discharge (PD) is the breakdown of a small part of insulation on equipment that is under high voltage (HV) stress. It is one of the major causes of catastrophic failures in HV equipment. PD mechanisms in HV Alternating Current (AC) systems are well understood and there is a growing body of knowledge around effective detection, monitoring and mitigation techniques under these conditions. However, there is a lack of knowledge and experience in the industry relating to PD under High Voltage Direct Current (HVDC) conditions. SSEN is investing significantly in HVDC cables, a trend replicated by the rest of the GB industry where there is proliferation of interconnectors and connections to offshore renewable sources of energy. To better prepare for the growth in use of HVDC, there is recognition for the imperative to know more about the mechanisms and characteristics of PD under these conditions.

The efficient running of high voltage Alternating Current (AC) networks involves, among other things, the management of reactive power flows. Transmission lines and cables tend to generate reactive power which requires to be compensated for to manage voltage profiles and reduce energy losses on the system. During periods of low loading, the voltage on a long transmission line or cable may increase along the circuit with the potential to fall outside the operational limits and equipment voltage design ratings which could result in equipment failure. One effective way to manage system voltages within desired operational limits is the use of shunt reactors where the system is susceptible to high voltages. The transmission networks in GB have several installations with shunt reactors connected in different configurations including, but not limited to, line connected, busbar connected and auto-transformer tertiary connected to manage system voltages.

The scope of this project is to conduct a series of tests, including field trials, to benchmark the performance of the Refase system against existing protection methods. An evaluation will establish if the Refase system is a viable solution to the problem statement detailed within the PEA document.

SSEN RainMan Project was the first UK real-time field monitoring system installed with a Low Power Wide Area Network communication medium (referred to here as LoRa). The LoRa network gathers real-time information from monitoring equipment using an Internet of Things (IoT) platform to collect data. The SSEN RainMan Project specifically developed pole movement detection IoT, to monitor the status of the wooden poles across the Isle of Skye.

The System Operator Transmission Owner Code (STC) has been amended recently to include, for future requirements, the transfer of elements of Phasor Monitoring Unit (PMU) data directly to the National Grid System Operator. SSEN presently views PMU data on the Secondary Operational Network (2nd OTN) by directly contacting the PMU. SSEN has no facility to actively gather the PMU data, nor is it possible to make elements of PMU information available to a third party.

Phasor Monitoring Units (PMUs) are being more widely installed across the UK electricity network; as protection and control technology develops. The PMUs can detail the shape of the AC electrical wave at the monitoring point; which can be used to provide several key electrical system parameters and significantly aids knowledge of how the network operates under both normal and abnormal conditions.

SSEN continues to develop an extensive Transmission Network to support both generation and subsea interconnectors. As a consequence, the population of cable assets operating at 132kV continues to increase, generally all of which are extruded XLPE. Cable failure at 132kV and above, although uncommon, is extremely costly due to the necessary repairs and potential loss of network capacity. Unanticipated cable failures can occur due to a lack of routine maintenance which for cables generally consist of pressure testing to detect any defects.

SSEN continues to encourage the development of generation capability within its network. However, as a consequence of the growth, it is inevitable that some wind generation schemes may encroach or come close to existing on-shore infrastructure such as Transmission Overhead Lines. The question being posed is “what effect and at what proximity do wind generators introduce an undesirable effect on existing conductor configurations (single, twin, quad) and conductor types (ACSR, ACCC, HTLS and both round or trapezoidal) used on transmission overhead lines, specifically accelerated deterioration and ageing from wake induced vibration.

The GB power system is rapidly evolving as conventional synchronous generation is decommissioned and ever greater levels of renewable sources are connected leading to a much lower level of system inertia and lower short circuit levels.

At the same time there are increasing numbers of HVDC links and Flexible AC Transmission systems (FACTs) devices being connected in close proximity in parts of the system. The potential for adverse control interactions between these devices is rising and needs careful consideration within the context of a potentially weaker GB system.