Fingrid’s long-term partner Omexom provides construction, installation and maintenance services for the generation, transmission and distribution of electricity. Cooperation between Vaisala, Omexom and Fingrid has proven to be an effective way of operating, as each company contributes to the project its own expertise. Omexom acquired the dissolved gas analysers and installed them in transformers in October 2020.
Otso Takala, Project Manager at Omexom says that they received good support from Vaisala’s expert in different phases of the project. ”We quickly got the product information we needed from Vaisala’s experts. Our team participated in online training on the installation of dissolved gas analysers, and during the installation, we discussed with the Vaisala team. The whole process was smooth,” explains Takala.
OPT100 DGAs play an important role in condition-monitoring of Fingrid’s transformers. They continuously provide up-to-date information on the concentration of fault-generated gases in transformers. Therefore, the changes in the transformer can be detected already at a very early stage, even in real-time.
”Fault-generated gases as such do not complicate the operation of the transformer. However, they are a symptom of some change. We need to find out that the increase in the amount of gas is not dangerous for the use of transformer,” explains Mertanen.
He notes that transformers are individuals, and each of them generates gases in a slightly different way. Therefore, transformers do not have common, absolute cut-off values to assess the importance of change.
Reducing Visits to the Transformers
”It is essential to know the behavior of the transformer in different situations and to identify the changes. Fault-generated gas analysers help us to catch the turning point, from which we can assess what has caused the change. For example, an external event related to a normal operating load situation can change the operation of the transformer.”