Acoustic hybrid sensor for BDV monitoring in insulating oil

The flawless operation of a power transformer is essential to a functioning “smart” grid. Measurement of the dielectric breakdown voltage (BDV) of insulating oil in real-time and online, is the most crucial and desired feature to manage the high-energy power network. Established good laboratory practices have shown that the BDV is mainly dependent on two major factors: absolute moisture (Wc) and total acid number (TAN) of the oill. Absolute moisture can easily be measured on-line by already established methods, while a metering of the TAN could not be realized until now. This confinement inspired us to create a piezo-acoustic-resonator sensor to estimate these two critical factors Wc and TAN.