Naveed Muhammad Fahad, Amaar Akasha, Khan Saad Saleem, Omar Muhammad, Larkin Stephen
Frankfurt University of Applied Sciences, Germany.
Technical University of Dortmund, Germany.
Heliyon. 2024 Dec 9;10(24):e40995. doi: 10.1016/j.heliyon.2024.e40995. eCollection 2024 Dec 30.
The contaminated transformer oil is one of the major causes of failure in the power system. Detection and continuous monitoring of moisture content in transformer oil is required for the smooth operation of a system. In this paper, a Fractal-based Sinusoidal-shaped Capacitive Sensor (FSCS) is proposed to increase the contact area between capacitor plates and dielectric medium by 17.3%. The proposed design offers minimal resistance to the flow of a mixed medium and can detect moisture content accurately. The variation in transformer oil, water, and mixture due to the temperature is considered to avoid false readings and alarms. The Equivalent Series Resistance (ESR) is also measured along with the equivalent capacitance to increase the accuracy of FSCS. A minimum detection limit of 5PPM is observed for a proposed sensor. The switching mechanism is integrated with the proposed design to make it reconfigurable and change the contact area with the impurity and sensitivity of the sensor. The large contact area and higher sensitivity mode are activated separately in order to avoid false readings. The sensor with a higher fractal stage achieves a sensitivity (fF/5PPM) that is 18.22 times greater than that of the lower fractal stage, making the higher stage more sensitive. As a result of switching, further substages of the fractal stage are formed. Each fractal stage can have multiple substages. The sensitivity of any particular substage increases as its fractal stage increases.
受污染的变压器油是电力系统故障的主要原因之一。为确保系统平稳运行，需要对变压器油中的水分含量进行检测和持续监测。本文提出了一种基于分形的正弦形电容式传感器（FSCS），该传感器可使电容器极板与介电介质之间的接触面积增加17.3%。所提出的设计对混合介质流动的阻力最小，并且能够准确检测水分含量。考虑到温度对变压器油、水及其混合物的影响，以避免误读和误报。除了测量等效电容外，还测量等效串联电阻（ESR），以提高FSCS的精度。所提出的传感器的最低检测限为5PPM。开关机制与所提出的设计集成在一起，使其具有可重构性，并改变与杂质的接触面积以及传感器的灵敏度。为避免误读，分别激活大接触面积和高灵敏度模式。具有更高分形阶数的传感器实现的灵敏度（fF/5PPM）比低分形阶数的传感器高18.22倍，这使得高分形阶数更灵敏。开关操作会形成分形阶数的进一步子阶数。每个分形阶数可以有多个子阶数。任何特定子阶数的灵敏度都会随着其分形阶数的增加而提高。
