Have you ever wondered what happens with the humidity that generators and engines acquire? Sebastián Marín shares with us his master's thesis and his main findings:
- If the humidity in the rotating machines indicates, the possibility of "chemical attacks", as the experts call it, is reduced and prevents the decrease of the dielectric rigidity.
- Especially in generation plants and in places where the engines of critical production processes are used, the analysis of the presence of moisture in rotating machines is a crucial factor to pay special attention to.
- So far, dielectric spectroscopy in the frequency domain has only been used in transformers; A characterization on rotating machines (generators / motors) had never been done.
At the IEEE - Andescon congress in Cali on August 24, the engineer Sebastián Marín presented his article: "Characterization in Medium Voltage Stator Coils using Dielectric Frequency Domain Spectroscopy" which was chosen for its oral presentation. In addition to Sebastian, Carlos Platero, researcher at the Polytechnic University of Madrid, with more than 7 patents in electrical machines and Francisco R. Blánquez, power electronics engineer at CERN in Switzerland, participated in this research.
To perform this characterization, Omicron's dielectric spectroscopy measurement equipment was used, a device not currently used in Colombia for the diagnosis of humidity in transformers, unlike in Europe and the EU. This through measurements in a coil, varying the amount of moisture in it to verify the possibility or not of characterizing the moisture content.
Using an experiment that also simulated the core of the rotating machine, three different humidification and heating processes were performed to verify the behavior of the delta tangent in the frequency domain and also verify the repeatability of the process.
The three tests or processes were carried out with different times of humidification and heating, the injected current also varying to heat the coil, and from this an analysis was obtained on the effect of this variation on the results. Finally the tests showed that the procedure and the measurements are repeatable and allow to characterize the amount of moisture contained in a coil.
In the long term, when the country is more familiar with these tests, HMV will be in a technical condition to perform them and, finally, perform an optimal monitoring of the transformers. When this methodology matures for rotating machines, it will also have a competitive advantage opening a possibility to the humidity diagnostic tests in rotary machines for HMV.
Measuring device
- 5μHz - 5kHz
- Voltage up to 200 V
- Combines the FDS and PDC technique to accelerate measurement processes
- Details the connection diagrams for the different connection scenarios
- Includes software to perform moisture analysis in transformers
Download the paper here!