Edinburgh Napier University

  Partial discharge (PD) is a phenomenon that can occur in power transformers which can lead to the degradation of the insulation system that resulting the failure of the power transformer. The power transformer uses oil as its insulation medium. An acoustic pressure wave generated by a partial discharge in oil can be detected by using Acoustic Emission (AE) sensors. However, the position of AE sensors needs to be determined to ensure that the sensors can effectively detect and capture the signals produced by partial discharges occurring within the transformer. The acoustic emission sensor can identify the PD between 10 kHz and 300 kHz. This paper presents the simulation of acoustic waves for oil propagation in a model transformer tank and its pressure that is detected by AE sensor using the finite element method (FEM) approach. In this research, two locations of AE sensors are simulated which is on the wall of the transformer and inside the power transformer tank. Based on the acoustic pressure and time of arrival, the propagation of the acoustic PD signal is being examined. The result shows that the acoustic pressure wave is getting bigger as the time increase. Its amplitude decreases when the radius of the acoustic pressure wave increases. The placement of the sensor either inside or outside of the transformer tank does not affect the amplitude of pressure detected by the acoustic sensor.