Grant: Collaborative Research and Development Grants

In North America and around the world, high voltage transmission lines are generally made of aluminum conductor steel reinforced with a design life of 50 years, and having a real field longevity of around 60 to 75 years. Today, most high voltage conductors around the world have been in service for more than 40 years, and consequently require more and more inspection and repair operations. Natural Resources Canada forecasts see Canadian electricity demand increasing at an estimated rate of 1 per cent per year for the next 25 years. Therefore, the construction of transmission lines, as well as new and greener power generation plants should be on the rise over the next decades, generating the need for major technological improvements. This will consequently push up the demand for state-of-the-art line accessories, as well as for monitoring cost reductions. This project targets these anticipated needs and proposes the design of an instrumented conductor suspension clamp capable of detecting and monitoring the degradation of in-service power transmission strands. It also aims at producing a modeling procedure for numerical prediction of strand fatigue life. The project methodology rests on an innovative finite element model providing detailed descriptions of the conductor internal degradation mechanisms. While the foundations of the modeling strategy have already been established by members of the project team, the present research proposes to complete the procedure by the addition of an interwire contact stress analysis allowing predictions of wear and fatigue degradation of the conductor close to the suspension clamp. After a complete validation campaign, the final modeling tool will allow the identification of the parameters defining the internal degradation mechanisms, as well as the formulation of descriptors to complete the portrayal resulting from existing standard indicators. The smart clamp design will associate specific sensors to each indicator. The modeling tool will be helpful for Helix Uniformed during the evaluation of any new clamp design. The project relies on one Ph.D. student and on one Master's student.