Locating faults in onshore aluminium cables

SSE Renewables is a leading wind farm operator in the UK and Ireland, part of the SSE group based in Perth. SSE Renewables is a generating company as well as one of the largest UK energy providers.

The challenge is to deliver a cost-effective method of monitoring array cable condition on-load and locating a fault as soon as it has occurred, in real time.

At present, cable faults are established through condition monitoring and personnel experience with conditions that lead to a cable becoming defective. Any inspection system should be capable of pre-emptive fault prediction and ideally the solution should be non-intrusive and retrofitted to cables on existing wind farms.

Across the fleet a reduction of technician intervention, turbine downtime and hazardous tasks is a priority. The sought solution should contribute to these goals.

Array (inter-turbine) cables are installed in jointed lengths (up to 3 km) from one turbine to its neighbour, forming a string (collection circuit) feeding the substation. Array cable faults are not automatically detected and located. In the event of failure, a visit to the relevant substation is required to confirm failure status. A Megger tester (or similar) is then connected at the associated substation and used to predict a fault location. All wind turbines on the affected array are offline until the fault is located, and a repair is implemented. This typically results in significant downtime and lost revenue.

In winter months when the weather is not suitable to enable access, downtime can be extensive, resulting in a large amount of lost power generation.

SSE Renewables is looking for innovations in monitoring the cable and establishing the potential failure point in the cable from the sub-stations in as near to real time as possible. Ideally, this should aim to replacing or mitigate the need for the manual Megger test e.g. by inline tracing.

It is envisaged that solutions will include deployable sensors on cables or in substations that require data to be collected from them. We believe there is also potential for AI and machine learning to reduce the level of technician expertise required to diagnose faults.

Fault finding and repair requires significant deployment of both internal resource and external contractors. All tasks are actioned under the required safety standards and permits; however, teams are required to work in often challenging conditions on site (especially in winter months).

Proposals are welcome for:

• Existing market-ready technologies
• Established solutions from other sectors of industry which can be adapted for this application.
• Development proposals based on existing competences.

Potential solutions may come from;

• Nuclear
• Rail
• Offshore wind
• Networks and Grid
• Construction and infrastructure
• Oil & Gas
• Digital
• AI and machine learning

Rewards and benefits

Finalists will be given an opportunity to pitch to SSE. For successful applicants, the package may also include:

• Support from the KTN and SSE Renewables
• Support with the development of a prototype or pilot.
• Technical and commercial support from SSE Renewables
• Introductions to relevant Catapults or potential collaborations and any applicable funding streams
• A place in KTN or Catapult events
• A potential business collaboration
• Sample data sets and/or trial support.

Functional Requirements

• Solution required to monitor the condition of 33kV (630mm², 3-phase) aluminium core array cables used in onshore wind farm applications. Cables will be several kilometres in length.
• Solutions should reduce the need for on-site physical inspection or fault code reading.
• Solutions should reduce time and amount of physical intervention compared to that required using Megger-based fault finding.
• Solutions should reduce or preferably avoid the need for whole array shutdowns during fault finding and rectification.If a permanently installed system is required, it should require minimum routine intervention or monitoring.

Technical Characteristics

• In the event of a cable fault (typically presenting as an earth fault), the solution should be capable of providing an indicative cable fault location.
• Solutions should be able to operate remotely.
• Solutions should be flexible in their ability to scale and customise with regard to different array configurations.
• Technologies that can be readily transferred to this application would be preferred – e.g. TRL level 6 and above.

Operational Conditions

• The cable arrays are on hillsides in difficult to reach areas
• The equipment may be installed inside sub stations.

Deployment Timescale

• Launch of the Competition: 27^th October 2020
• Deadline for applications: 30 November 2020
• Selection and notification of finalists: 8 December 2020
• A presentation day (Video Conference) very early in the new year (2021).
• Solutions should be prepared for:
  • Feasibility assessments, where needed, to be completed within 1 month of competition win
  • Fully deployable for prototype testing at site within 3 months of feasibility selection win.
• Full commercial deployment may start after the project prototype has demonstrated it can detect a fault and support identification of the location.

Cost requirement and market opportunity

• A cost breakdown is required from a solution provider for SSE to get a cost model for future deployment.
• On completion of successful trials, the immediate opportunity is to deploy a service or equipment on a location with 8 sub-stations. SSE has a portfolio of c.2GW of onshore wind that utilises over c.50 sub-stations and to which the solution could also be deployed if found to be of benefit.

Eligibility and assessment criteria

Entrants to this competition must be:

• Established businesses, startups, SMEs or individual entrepreneurs
• UK based or have the intention to set up a UK base

Applications will be assessed on:

• Relevance to the topic
• Innovative nature of the subject
• Coherence of the proposed business model
• Feasibility/ economic viability
• Development potential
• Maturity of project/solution
• Ability to launch project quickly/Ease of implementation
• Price/quality ratio
• Suitability for the UK and European Market

IP and Potential Commercial Route

• Existing background IP associated with a potential solution will remain with Solution Provider(s). Where any new IP generation is envisaged, it will be subject to the mutual IP agreement of the Solution Provider(s) and Innovation Challenger.
• Any commercial deployment of transferred solution or newly developed solution, through licensing, joint venture, partnership or direct investment, will be subject to the commercial agreement between the Solution Provider(s) and Innovation Challenger.
• Where necessary, a non-disclosure agreement (NDA) may be signed to uphold confidentiality in the engagement between the Solution Provider(s) and Innovation Challenger.
• Innovate UK and KTN do not take any share of IP ownership or enter into commercial venture through the Innovation Exchange programme.

Image credit: Colin Keldie

To apply, visit the Innovation Exchange site here.