Evaluation of Low Cost Piezoelectric Sensors for the Identification of Partial Discharges Evolution

Daniele F Akiyoshi,Rudolf R Riehl,José V F Leão,Jorge A A Rey,Marco A Rocha,André L Andreoli,Bruno A De Castro

doi:10.3390/ecsa-5-05722

Daniele F Akiyoshi, Rudolf R Riehl + Show 5 more

Open Access

https://doi.org/10.3390/ecsa-5-05722

Copy DOI

Abstract

Transformers are essential equipment in electrical energy systems and their failure may lead to the loss of a power supply. Both industry and science have sought to develop sensors and low-cost solutions for the correct diagnosis of their failures. Thus, the use of piezoelectric sensors in the diagnosis of partial discharge in power transformers has been growing significantly, in order to ensure the reduction of maintenance costs, as well as the quality of electric power supply, since this type of failure can lead to a significant cost of repair. In many cases, when partial discharge is detected, there is no immediate need to promote transformer maintenance. In this way, it becomes reasonable to study the evolution of this phenomenon, so that the maintenance of the device can be scheduled and performed correctly. In this regard, this article presents a feasibility study of a low-cost piezoelectric transducer for the identification of the evolution level of partial discharges. For this purpose, in a 30 kVA distribution transformer, three corona partial discharges were produced under three different voltage levels, using a copper electrode. The low cost piezoelectric sensor was coupled to the transformer housing. The acoustic emission signals of the three partial discharge levels were captured and analyzed by the use of acoustic signal metrics, such as energy, peak value, and power spectral density. The experimental results indicated that the low cost sensor is able to identify the evolution of the partial discharge intensity, since the values obtained by the metrics are directly related to the partial discharge levels. Therefore, the results reported in this study indicate that the piezoelectric transducer has a great applicability in diagnosing the partial discharges evolution, and, thus, can assist in the planning of electrical maintenance.

Highlights

Power transformers are essential equipment in electrical energy systems and their failure can affect the quality of electric power supply or may lead to lack of it, resulting in losses to consumers and electric companies [1,2,3,4]
The objective of this research is to evaluate the performance of piezoelectric sensors in the identification of partial discharge (PD) evolution
As the objective of this article is to verify the viability of the piezoelectric diaphragm in the identification of the phenomenon evolution, we analyzed the spectral content, as well as the energy of the acoustic signal generated by the three inserted PD

Summary

Introduction

Power transformers are essential equipment in electrical energy systems and their failure can affect the quality of electric power supply or may lead to lack of it, resulting in losses to consumers and electric companies [1,2,3,4]. Nowadays, both industry and science have sought to develop sensors and low-cost solutions for the correct diagnosis of their operational condition. A well-known method is the acoustic emission, which employs sensors to capture the acoustic signals generated by PD [5,6]

Objectives

Results

Conclusion