Supporting National Grid Electricity Transmission (NGET) Cable Innovation Project – Doble Engineering Company
Doble Engineering Company supports its clients with products and services, factory audits and test witnessing, consultancy and forensic investigations. Occasionally, Doble assists clients with their innovation activities.
Recently, National Grid Electricity Transmission (NGET) invited Doble and other suppliers to participate in an innovation project investigating partial discharge behaviour in silicone oil-filled cable sealing ends (CSEs). Currently, CSEs are routinely surveyed using tools such as radio frequency interference (RFI) for signs of deterioration and NGET wanted to investigate reducing the cost of this work.
The University of Manchester (UK) built a cable test loop with two terminations in order to facilitate testing. One of the sealing ends contained an artificial defect simulating the degradation problem. The test arrangement was designed to allow the independent application of voltage and current.
Oliver Cwikowski, NGET innovation engineer, explained the genesis of the project, “Both NGET and other international network operators have experienced a number of performance issues with this type of sealing end. Consequently, this project is focused on seeking solutions for detecting any internal degradation before it causes operational problems.” He added, “Early detection means appropriate intervention can be planned leading to less disruption to the electrical grid.”
During the testing Doble applied electric, acoustic and radio frequency detection methods to the cable sealing ends. Falk Werner, partial discharge development manager at Doble, who led the testing activities said, “This was a fantastic opportunity to apply multiple partial discharging sensing methods simultaneously on the same test object.” He continued, “Working in the high-voltage laboratory on full-scale energised assets allowed considerable flexibility in the methods and sensors we could apply, without the time constraints we often face when testing in the field.”
After a full day of testing Oliver Cwikowski noted, “Having the support of Doble and other companies during this innovation project is essential to moving us towards a solution which can be ultimately transitioned to business as usual.”
Doble is proud to collaborate with NGET and other clients on innovation projects. These arrangements provide a unique window into the problems facing the electric power industry. “Doble was happy to support NGET in this project,” said Chris Capel, senior test engineer at Doble, adding that, “Such work exposes us to the emerging challenges faced by our clients.”