Working at Doble: A New Adventure Each Day
I have to admit my job prior to working at Doble Engineering Company was a bit monotonous. My former colleagues would say they enjoyed performing distribution transformer maintenance because each workday was predictable. All the transformers were similar; similar voltages, similar designs, similar ratings, and nearly the same scope of work to carry out on each one. At that time, I was responsible for transformer testing, so I was performing the same set of tests on a routine basis. Initially, this was new and interesting, but once I gained experience and was familiar with the job, I found the repetitive nature of it boring. It was like solving the same crossword puzzle for a second time; there was not much challenge in it.
A New Beginning
When I joined Doble more than a decade ago, I gained an entirely new perspective on transformer services. I now travel the world, visiting manufacturers, large and small customers, supporting international working groups, and working with engineers from different countries and cultures. Whether I am travelling by helicopter to test a transformer located on an oil rig in the middle of the North Sea or troubleshooting an HVDC transformer associated with a long-distance subsea power cable between two European countries, no two projects are alike. There are now endless crossword puzzles to be solved!
Troubleshooting Transformers at Sea
One of my most memorable assignments was working on a vessel laying subsea gas pipelines. This floating factory contained a production line assembling the pipeline from twelve-meter-long sections of pipe. Each section moved through different stations before welding to the ever-growing pipe being laid from the vessel.
After each new section of pipe was welded, the ship would move backwards a distance equal to the length of the pipe extension in order to deposit it into the water. To maneuver the 300-meter-long vessel with sufficient precision, regardless of weather conditions, the vessel is fitted with eight directional thrusters, each powered by a dedicated cast resin transformer.
Some of the transformers had failed and Doble was engaged to perform an investigation. I flew to the ship to inspect these units while the vessel was on a week-long trip to the shipyard. Moving the test equipment around the ship, up and down ladders, was one of the first challenges to overcome, and one not normally experienced in a standard site assessment.
I carried out a full sweep of tests and managed to identify a serious problem in one of the units. The power factor test revealed an insulation problem and because the units were fitted with electrostatic shields between windings, I was able to identify which winding had the problem. Analysis of all data, combined with the history of previous failures, led us to conclude that vibration was the likely cause of the problems with these cast resin transformers.
Once back in dock, each unit was equipped with vibration-damping pads during the refurbishment. As added insurance, Doble IDDs (typically used to monitor bushings) were installed to monitor any future drift in the power factor of these units during operation. Today we would recommend use of the new Calisto™ T1, all-in-one condition monitoring system to expand the functionality of the system.
A Decade of Adventures
A decade later, I can say that my work at Doble is still fun and anything but predictable. My work on transformers brings new experiences and unique technical challenges to be solved. This is an endless adventure and I surely will have a handful of stories to tell my grandchildren when the time comes.
ADDITIONAL INFORMATION
- Blog: Doble Supports NB Power Subsea Cable Replacement Project
- Paper: On-Line Power Factor Measurement on a 6MVA Cast Resin Transformer
- Doble Power Cable Services
- Doble Careers
