| Title |
Characteristics of Ultrasonic Signals Caused by Corona Discharge in Air |
| Authors |
이상우 ; 김인식 ; 이동인 ; 이광식 ; 이동희 |
| Abstract |
Measurements of ultrasonic signals caused by corona discharges were performed by using an ultrasonic measurement technique to analyze the development states of coronas in a high-voltage power apparatus. We also examined the relationship between discharge magnitude and ultrasonic pulse number to diagnose the deterioration of electrical insulation by corona discharges. From these results, it was found that ultrasonic signals due to corona discharges can be firstly detected at the peak value of positive polarities prior to the breakdown voltages, and the magnitude of ultrasonic signals was closely related to the current pulses by the corona discharges when ac voltages were gradually raised, and it appeared that ultrasonic pulse number was proportional to discharge magnitude. Attenuation time-delaying and directivity characteristics of ultrasonic signals propagated to air by using ultrasonic oscillation and receiving systems are reported as a basic data of ultrasonic, measurements in out-door HV apparatus. |