Design and Development of a Bio-Inspired UHF Sensor for Partial Discharge Detection in Power Transformers

Abstract

In this paper, the design and development of a bio-inspired UHF sensor for partial discharge detection in power transformers is presented. The UHF sensor was developed for external use in dielectric windows of power transformers. For this purpose, a microstrip antenna was designed with a radiating element shape based on the leaf of the Jatropha mollissima (Pohl) Baill plant. Then, an epoxy coating and an aluminium enclosure were developed to protect the antenna against corrosion and to provide mechanical support, external noise immunity, and a lifetime compatibility with power transformers. In order to verify the electrical parameters of the developed sensor, measurements of the gain and the reflection coefficient were performed in an anechoic chamber. Lastly, the antenna sensitivity for denominated partial discharge (PD) detection was compared with the IEC 60270 standard method. For this purpose, simultaneous tests were carried out in a partial discharge generator setup, composed of an oil cell with needle-plane electrodes. The experimental tests demonstrated the effectiveness of the sensor for detecting PD signals with apparent charge values higher than 35 pC.

UHF Partial Discharge Location in Power Transformers via Solution of the Maxwell Equations in a Computational Environment

“…Initially, at least four UHF sensors must be installed in the equipment tank through dielectric windows, as previously described in [8]. The sensors must be installed with the maximum spatial distance between them on the surface of the transformer tank and not geometrically placed on the same plane [10], as illustrated in Figure 1.…”

“…Several techniques have been used to detect PD within a transformer, such as the standard method defined by IEC 60270 [1], dissolved gas analysis (DGA) [2,3,4], the acoustic method [5,6,7] and the ultra-high frequency (UHF) method [8,9,10,11,12]. In addition to PD detection, studies have been carried out to determine the location of the PD based on the acoustic wave generated by the PD or the electromagnetic radiation in the UHF band.…”

Design and Application of a Metamaterial Superstrate on a Bio-Inspired Antenna for Partial Discharge Detection through Dielectric Windows

“…These optimized geometries can be addressed in the shapes of living beings developed in order to provide greater efficiency regarding the ability to survive. Hence, aiming to achieve a better radiating efficiency, bio-inspired antennas use the shapes of plants or animals as basis for their design [21,22,23,24,25,26].…”

“…Therefore, the main objective of this paper is to design a metamaterial for gain enhancement that can be used as superstrate over a PMA developed for PD detection through dielectric windows. The PMA used as reference is a bio-inspired structure based on the Jatropha mollissima (Pohl) Baill leaf that was developed and presented in a previous work [26] and meets the size, bandwidth, and gain values requirements for PD detection through dielectric windows in high voltage equipment. Hence, this work aims to improve the PD sensitivity of detection of the structure presented in [26] through the application of a metamaterial superstrate representing a dielectric window, allowing a more accurate detection of PD inception (low intensity pulses).…”

Quantitative Analysis of the Sensitivity of UHF Sensor Positions on a 420 kV Power Transformer Based on Electromagnetic Simulation

“…This method has the advantage of being resilient against external noise [3] and providing the possibility of three-dimensional PD source localization [4]. Recent developments have included different designs of UHF sensors [5][6][7][8][9], PD source localization algorithms [10,11], and a calibration proposal [12,13] so that the method can be introduced in addition to the IEC 60270 PD measurement [14] during transformer acceptance tests. Since UHF PD measurement requires the placement of UHF sensors at different positions on the transformer tank [9,15,16], it is required to analyze the sensitivity of various prospective sensor positions.…”