Comparison of the acoustic performance and positioning accuracy of three kinds of planar partial discharge ultrasonic array sensors

Abstract

The detection of partial discharge (PD) sources in electrical equipment is very important for safe and stable operation of power systems as it allows for the timely elimination of insulation faults. Cross, circular and square array sensors are commonly used in the detection. In order to determine which form is the best, this study compares the acoustic performance and positioning accuracy of the different arrays. Firstly, this study does research on the quantitative evaluation of the acoustic performance of the planar ultrasonic array sensors. Sparse signal decomposition theory is then applied to find three different directions of arrival (DOAs) of the signal from the PD source to the array sensor. Next, using two of the DOAs (azimuth and pitch), the location of the PD is determined as the centre of a sphere whose surface is tangential to the three DOAs in three different planes. The positioning accuracy of the sensors is then derived. Finally, simulation results show that the acoustic performance of the circular array is the best. It also produces the most accurate location results. Therefore, a circular array is the optimal form to use for the construction of a planar array sensor.