The Investigation of Detect Position of Partial Discharge in Cast-Resin Transformer Using High-Frequency Current Transformer Sensor and Acoustic Emission Sensor

Abstract

The lifetime of a cast-resin transformer mainly depends on the condition of insulation material. Partial discharge (PD) is an important reason for insulation deterioration in cast-resin transformers. Identifying the position of PD is very necessary for damage assessment while the transformer is still operating, and the transformer is covered by housing. This paper proposes the investigation of a cast-resin transformer using an AE sensor and HFCT sensor to specify the precise source of PD. In this study, four AE sensors were used to find PD sources, and the high-frequency current transducer (HFCT) technique was used to identify the PD source and the criteria level. The experiment, in the first two parts, identified the possibility of PD, which includes the position of PD. The final part of the experiment verified the position of the PD source of a cast-resin transformer and confirmed the inspection results. AE and HFCT sensors can be used to detect the location of PD sources, confirming the position of the PD source by sensor detection. In addition, the evident partial discharge picture on the insulator surface of high voltage side. The process successfully and accurately identifies and locates the PD source.

Effect of sensor position on the measurement of acoustic wave produced by partial discharges

“…The time of arrival of the acoustic wave is thus given by equation (4) : where V oil and V Steel are respectively the longitudinal propagation velocities of the signal in oil and steel. The one used to calculate the flight time for a direct path is given by the relationship [ 7 , 12 ]:

Fig. 3 Model of propagation of an acoustic wave in a transformer.

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“…The degradation of the insulation system is due to a harmful phenomenon called partial discharge (PD) [ [6] , [7] , [8] , [9] , [10] ]. The PD level is closely related to the insulation level of a transformer, which is why monitoring PD provides information on the condition of the insulation system [ [11] , [12] , [13] , [14] ]. To ensure the proper functioning of the transformer and to ensure its reliability, permanent monitoring of the PD is necessary [ [15] , [16] , [17] ].…”

Experimental Study on the Identification and Diagnosis of Dynamic Crack Propagation in the Piston Rods of Process Gas Compressors in Underground Gas Storage

“…AE involves the propagation of elastic waves within a material, driven by structural changes induced by plastic deformation, crack growth, and the redistribution of internal stresses, ultimately leading to the release of energy [34]. This technology is currently being applied to various materials, including metals [35], concrete [36], composites [37], and polyethene [38], and to various engineering structures, such as bridges [39], pressure vessels [40], transformers [41], aircraft structures [42], and railway axles [43], for damage monitoring and identification.…”

The Characterization Analysis of the Oil-Immersed Transformers Obtained by Area Elimination Method Design

“…In addition, characteristics are required such as steel core, winding unit, insulation, cooling in winding unit and calculation of power loss and short-circuit impedance percentage. In addition, it also takes into account the distance factor to avoid problems from the partial discharge (PD) of the transformer when on load [9,10]. However, the values obtained for the transformer design using the AE technique are for design purposes only.…”