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Harald Mayer |

New sensors - keep your transformer healthy

Fewer failures, lower maintenance costs: New multi-gas infrared sensors deliver fast and precise information on your transformer’s health.


Components in energy systems around the world are aging, even as power requirements increase. Efficient, condition-based maintenance of equipment like transformers is playing an increasingly important role as a means of safeguarding operation and minimizing risks and maintenance costs. The solution: an online health check using DGA (dissolved gas analysis), and Siemens Customer Services have added new, outstanding DGA infrared sensors for transformers to its portfolio to enable this.


“In the past, customers would frequently send us oil samples from their transformers. Some still do. Extracting the sample is not without risks. After analyzing the oil, we know how the transformers are doing and what they need,” says Siemens Product Manager Fabian Kuder. His specialty is sensors, because now even transformers have entered the digital age. Their smart sensors can partially replace manual testing and perform continuous analyses – online and seamlessly integrated into the customer’s system.


Save money: Detect faults before they occur

Siemens has long been offering sensors that can, for example, determine the hydrogen content of transformer oil. Since January 2018, however, the Customer Service portfolio has included two new products with genuinely unique selling points: the Sitram Multisense 5 and 9 multi-gas sensors. Using a DGA method, they monitor and analyze the cracked gases dissolved in transformer oil. Cracked gases are byproducts of the chemical reactions triggered by the degradation of cellulose or oil molecules. Their composition and alteration can signal defects or material aging in transformers. “These changes are often in the 0.001 range. Our precision multi-gas sensors detect the changes, which allows them to identify about 50 percent of all potential faults in transformers faster than ever before. With this knowledge, we’re able to correct emerging defects before the transformer fails – which would be a total loss – or personnel are affected,” explains Kuder.


Robust and always precise: the measuring cell

What makes both sensors so special, according to Kuder, is the ingenious non-dispersive infrared (NDIR) technology with measuring cells that contain no moving parts and are therefore extremely robust. “Our sensors are unaffected by vibration or noise,” says Kuder. That’s why they can be installed directly on the transformer, they need no separate base, and they deliver highly consistent data even under harsh environmental conditions like sand, wind, heat, cold, and moisture. Says Kuder, “There are few multi-gas sensors on the market that use the same technology, and even fewer feature a compact design that allows installation directly on the transformer.”


Fast: analysis data available in near-real time

Using online data that’s available in near-real time, operators can work with Customer Services to reliably prevent transformer failures and schedule service activities more efficiently and as needed. Experts call this preventive maintenance. The Multisense 5, for example, analyzes the moisture contained in the oil as well as four gases (C2H2, H2, C2H4, and CO). The Multisense 9 analyzes an additional four gases (C2H6, CH4, CO2, and O2), which also enables early diagnostics: “The results immediately tell us whether anything is wrong with the transformer and what it is,” says Thomas Kessler, Head of Product Lifecycle Management for Transformers. Thanks to their compact dimensions, both sensors can be quickly and seamlessly integrated into the customer system and are maintenance-free.


Flexible: digital and analog service

“From the DGA sensor to highly developed plant management systems, we now carry the right sensors for all transformer types and applications,” says Leone Lattanzio, Head of Siemens Customer Services Transformers. “We now offer a complete digital monitoring portfolio for transformers.” Smiling, he adds, “But, of course, anyone who wants to keep taking manual oil samples is still welcome to send them to us.”



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