Study on the Audible Acoustic Features of Dry-Type Reactor under Typical Insulation Defects

Dry-type reactor is an important equipment in the power grid system, but the features in time and frequency domain of its audible signal under typical insulation defect discharge are not clear yet, which makes it hard to effectively carry out the fault diagnosis of dry-type reactor based on audible signal. Based on this, this paper builds a dry-type reactor audible signal insulation test platform based on a 10 kV dry-type reactor, sets up two kinds of insulation defects: winding lead wire aging fracture and metal burr defects, collects its discharge audible signal, and compares and analyzes the time and frequency domain features of the discharge signal, and gets the following conclusions: the discharge signal of winding lead wire aging fracture is obvious periodically, and the discharge signal of metal burr defects is in the shape of “Hump” with the period of 20 ms. Based on the study of acoustic feature of power spectrum, it is found that the acoustic power spectrum of winding lead wire aging fracture discharge has three-band feature, and the frequency point of average power is near 10 kHz. The power spectrum of metal burr defect discharge has double-band feature, which is mainly composed of high-frequency components. This study provides some technical support for the further development of dry-type reactor operating condition detection and evaluation based on audible acoustic.