Noninvasive method for online detection of internal winding faults of 750 kV EHV shunt reactors

Seven hundred fifty kilovolt extra-high voltage (EHV) shunt reactors are important power equipment that stabilize the normal operation of an entire 750 kV power grid. Internal winding faults of a reactor could be a difficult issue when the reactor is in service, and result in sudden equipment failure and significant economic losses. To prevent sudden catastrophic failure of equipment, online detection should be implemented to evaluate the state of the reactor properties when requested. In this paper, a noninvasive method based on online impulse frequency analysis was proposed and developed to detect internal winding faults of a 750 kV EHV shunt reactor. Initially, the safe implementation of the online detecting device was verified before field installation. Unlike in previous work, the online detecting device was modified and improved according to the specific situation of shunt reactors. Original fingerprints of 750 kV EHV shunt reactors were obtained and analyzed after site installation and normal operation of the detecting device. A fault simulation test was implemented to validate the method. This paper provides guidance on actual implementation of online impulse frequency response analysis on power equipment.