Case Study

Higher reliability at a lower cost

When a global engineering leader was contracted to refurbish several high voltage substations in Iraq, TE Connectivity (TE) supported them with a gas-filled bushing solution that delivered reliability, availability and safety – with dramatic cost efficiencies.

Alternative Solutions and Expertise

TE's capabilities and quick response to solving problems, brough a large multi-national company to inlist for help in determining which TE products would be best suited to refurbish serveral high voltage substations in Iraq.

While the standard operating temperature of the Gas Insulated Switchgear (GIS) in a typical High Voltage substation is 45°C, the technical designs for the GIS in the Iraqi substations was specified at 65°C. This increase in operating temperature meant that the standard solution offered by the supplier was a larger and significantly more expensive GIS bushing (the connection between the GIS and the Overhead Line) using a resin-impregnated stress cone.

A new solution would have to meet not only the supplier’s technical requirements and be able to operate in extreme conditions but it would also have to offer a dramatically reduced price point compared to the competitors. In addition, development to delivery was required within a tight turn around time of 16 weeks. 

TE was already well placed to meet the supplier’s requirements for this project. With a very strong technical department at their facility in Wohlen, Switzerland, and development and product management teams providing customer support, TE had the relevant high voltage design experience.

In addition, the supplier already had previous experience of TE’s alternative solution, a gasfilled bushing that had been qualified for standard applications since 2009. The qualification consisted of an extensive design and test program, so that they had an alternative to the standard solution.

The supplier contacted TE to ask whether the gas-filled bushing could be used for the Iraqi substations. TE’s engineers immediately carried out a feasibility study using a mathematical model to understand the temperature resistance of the specified electrical conductor.

The initial findings were positive, and these favorable results were repeated even when technical parameters were adjusted. At this point, a type test was held to support and prove the data at the supplier’s facility in Berlin, with TE supplying the test bushings.

The test required that three bushings be tested under electrical load at high temperature. The assembly of the bushing was done at the TE Site in Switzerland and the final assembly with tests was done in Berlin. Owing to the experience of the technical team in Wohlen in offering a highly customized service, the assembly was not an issue and the tests were successful in proving the theoretical calculations done by TE.

TE’s bushings for gas-insulated switchgear offer high reliability, availability and high degree of safety as well as being economically efficient. The solution maintains a long service life requiring little maintenance and therefore low life cycle costs. Its compact design, good accessibility and ergonomics deliver a high degree of adaptability to individual requirements. TE’s reputation and reliability was key to the development and qualification process to develop a product. Close contact with the purchasing department and project department ensured the process was streamlined supporting the complete special test program for this outstanding application. Based on the final project order, the production at TE Connectivity’s Axicom site in Wohlen was completed on time and on budget. A total of 300 bushings were installed in the substations with significant cost savings. Not only was the product qualified and delivered, but we also proved again the TE advantage - reputation, reliability and price.