Offshore Wind Accelerator: Type Test of Screen Connections

Call for entries from companies and consortia interested to undertake a study for the OWA Cables Technical Working Group (TWG-C) to advance cable accessory testing protocols, fill existing gaps, and align standards with the evolving needs of the industry, ultimately contributing to more reliable and resilient cable accessories across various applications and voltage levels.

Project objectives:

The main objectives of this work are to: 

  • Develop updated test requirements for type testing of cable screen connections, addressing the inadequacies identified in existing standards, for example, in thermal cycling, short-circuit, heat cycles, impulse, HVAC, and partial discharge tests. 
  • Establish a singular type test applicable to 33 kV, 66 kV and 132 kV, ensuring a universal standard for cable accessory testing. This test should be agnostic of the way in which screen connection is made, providing a holistic approach. However, it may be helpful to specify the expected differences between different approach such as welded/bonded foil/laminated screens. Every screen design other than stranded copper wires should be considered. 
  • Investigate and recommend new connection design agnostic acceptance criteria. Qualitatively, the contractor should establish contact resistance and temperature functional pass/fail trends and determine which should be included in standard acceptance criteria. For instance, criteria may include restrictions on contact resistance increase post-thermal cycling and limitations on the resistance factor ratio λ, as defined in CIRED recommendations. 
  • Expand the scope of testing goals and revisit the range of qualification beyond the current CIRED framework by incorporating considerations for radial TM forces, changes in conductor, screen and outer sheath materials, load cycle applicability etc., and other emerging challenges in cable accessories. 
  • (Optional) Explore the feasibility and benefits of modelling of steady state screen/sheath-loads (zero sequence currents) as well as short-circuit loads in screen/sheath (single-pole short-circuit in cable screens for HVDC interconnections where the wye point of transformers is solidly bonded). The primary goal is to agree on general test parameters and inputs.

Preferred Experience:

The type of Contractor expected to be best suited to delivering this work is a consultant or research institute. The ideal contractor would have:

  • Cable testing laboratory experience; 
  • Electrical as well as thermo-mechanical background; 
  • Some experience in root cause analysis.

Timeline:

  • Applications open: 9 April 2024 
  • Deadline for clarification questions: 30 April 2024 
  • Clarification document published: 3 May 2024 
  • Submission of full tender: 17 May 2024 17:00 BST

Offshore Wind Accelerator (OWA)

All clarification questions and tender submissions should be sent electronically, by their respective deadlines, to karolina.zieba@carbontrust.com with bethany.white@carbontrust.com in copy.

Tender Documents