SMIT Transformatoren BV designs and produces large-scale power transformers, used among other purposes for transporting electrical current via high-tension cables. The company is based in the Dutch city of Nijmegen and has some 300 employees. With 90 years of experience, SMIT enjoys an outstanding reputation as a manufacturer for markets in Europe, the USA and Asia.
Transformers are used to transform the electrical energy generated at power stations to a high voltage which can then be transported via the mains network. At the points where the energy is taken from the mains network, a transformer is then used to reduce the voltage again.
SMIT Transformers: made to customer specifications
The construction of a transformer requires considerable know-how and skilled manual work: the great steel housing contains two or three reels carrying lengthy, fine copper cables, intricately welded to one another, which are wound onto the wooden reel with the utmost care in a set pattern. These reels are set over a core of precisely sorted thin steel plates, and then inserted into the transformer housing. After the electrical connections have been laid, the housing is filled with oil. This serves as an insulating and cooling fluid for the transformer, which heats up significantly when in operation.
What is more, SMIT produces its transformers to customer specifications, meaning that there are no identical units rolling off the production line. Transformers have an average product life of forty years. With a price tag of around a million euros, they represent sizeable capital assets.
Customers request thermographic check
In the spacious hall of the High Voltage Lab at the Nijmegen site, brand-new transformers, many metres high, stand ready for their final inspection. This con-sists of a whole series of tension tests and investigations of noise generation, noise suppression and heat distribution.
”We don’t mass-produce standard transformers,” explains Ernst Hanique, High Voltage Lab Manager, who is in charge of the transformers’ final check: ”Our transformers are built to the customer’s specifications, which is why measurements and tests before final handover are so important. These usually go off without a hitch, but the worst thing that can happen is that we have to open up one of the transformers.”
To monitor the transformer’s heating and cooling
pattern, the Lab has purchased a FLIR Systems ThermaCAM P65 thermal
imaging camera. The camera makes it possible to monitor the temperature
distribution inside the transformer in minute detail, and to supply the
customer with accurate images of it. These infrared measurements soon
proved to represent added value for the customer.
”Some customers explicitly request a properly
documented thermographic check for their new transformer,” says Steven
Lauf, test technician and calibrator, and operator of the infrared
camera. ”The clear image quality of the ThermaCAM P65 and the integrated
visual camera provide a complete, coherent picture. And thanks to the
accompanying Reporter Pro software, we are now also able to provide this
information in a professional format.”
The reports generated by the software are stored
internally by the company: as virtually every transformer produced at
SMIT is unique, all documents for each one, from construction drawings
to acceptance records, are archived. The data is important for the
service department, which needs to be able to reach and repair any SMIT
transformer as soon as possible, anywhere in the world. ”And we have 80
year-old transformers which are still doing excellently,” adds Hanique
Interest in thermography is now being shown at other
departments in the company. ”The camera was an investment, and we took
some convincing to order this versatile model,” says Hanique, ”but we
now have a high-quality item which, as a fast, mobile, contact-free and
visualising measuring and inspection tool, is sure to find many other
applications in the company.”
Thus, thermography is helping SMIT to supply perfect transformers while contributing to a further quality increase and cost reduction at the company.
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