Location of partial discharges sources using sensor arrays

Occurrence of partial discharges (PD) is one of the basic criteria of high voltage devices insulation evaluation. Precise PD source location is crucial for undertaking maintenance of mentioned equipment. This paper concerns the issue of partial discharges sources location using phased rectangular arrays technique and high-resolution direction of arrival estimation technology. In addition to the theoretical assumptions of both techniques, the simulation result, in which an Uniform Rectangular Array (URA) was used for registration of the electromagnetic signals generated by defects in power transformer insulation system, were shown. To estimate the Direction of Arrival (DOA) of electromagnetic signals, that propagate from the discharge-generating defect to the transducer array installed on transformer tank, Minimum Variance Distortionless Response (MVDR) algorithm was chosen. The location of defect was determined using two intersecting lines defined by the DOAs from two URAs. With the ability to locate multisource discharges (even at very low signal to noise ratio - SNR), the adopted solution has advantages over conventional techniques.