Development of an Algorithm for Distinguishing Between Transmitted and Reflected Ultrasonic Signals Using A Hybrid Transmission and Reception Method with Non-Contact Ultrasonic Measurement Technology

Although technologies that allow the detection of abnormalities in high voltage electrical installations without power interruption are being applied, there are limitations in clearly determining facility faults. In particular, molded-type electrical equipment has a structure that completely seals internal components from the outside, making it difficult to detect internal anomalies. Therefore, it is challenging to detect early internal faults using existing power-on diagnostic method. In response, a new diagnostic method has been introduced that utilizes ultrasound to penetrate epoxy insulation and estimate the internal temperature of high-voltage molded-type transformer windings, along with a non-contact ultrasonic measurement technology. This paper, based on previous research, develops an algorithm for distinguishing between transmitted and reflected ultrasonic signals using a hybrid transmission and reception method with non-contact ultrasonic measurement technology. The performance of the algorithm was verified using high-voltage winding samples from a molded transformer specially fabricated for the experiment.