Estudo da aplicação de sensor eletromagnético para monitoramento remoto de parâmetros de qualidade do óleo mineral isolante em transformadores de potência

Abstract

Siemens Energy provides energy solutions, produces power transformers and offers after-sales maintenance service. In the structure of a power transformer, its insulating part consists solely of mineral oil and cellulose material. This electrical equipment has a long lifespan cycle and requires periodic maintenance. For this, oil quality analyses are necessary. Some natural deterioration of the oil, such as thermal aging, the presence of water, high temperature, dissolved gases, among others, caused by internal or external conditions, lead to a decrease in its insulating properties. Therefore, monitoring the condition of the oil is of utmost importance in order to avoid the occurrence of transformer failures. Therefore, a new real-time analysis sensor was tested in the Materials Laboratory of Siemens Energy Brazil - Jundiaí. This sensor uses electromagnetic field technology and is capable of measuring several characteristics of the insulating mineral oil in real time. Measurement tests of moisture, temperature, presence of dissolved gases and interfacial tension were performed, from bench methodologies comparing with the electromagnetic sensor. The results point to the need for further exploration of the sensor for this purpose since it presented interferences in the result mainly related to small changes in temperature.