Design of Dielectric Constant Sensor for Transformer Oil Condition Detection Based on All-Metal Metamaterial

This paper proposes an all-metal metamaterial based highly sensitive sensor for the microwave section of transformer oil condition. The sensor's resonator part belongs to the Complementary Split Ring Resonator (CSRR) structure. The sensing principle of the structure is realized by utilizing the electrical properties in the transformer oil. The difference between waste transformer oil and clean oil will cause the resonant frequency of the resonator in the sensor to change. The transformer oil conditions can be detected by detecting the sensor's resonant frequency. The simulation results show that when the dielectric constant changes from 2.9 of clean oil to 2.7 of waste oil, the resonant frequency of the sensor increases from 8.184GHz to 8.486GHz, and the resonant frequency difference is about 300MHz, which is relatively higher than the reported sensor. Further experimental research on the sensor will be carried out, and fine-grained detection, such as water content in transformer oil will be considered.