Measurement and Modelling of Leakage Current Behaviour in ZnO Surge Arresters under Various Applied Voltage Amplitudes and Pollution Conditions

Nurul Latiff,Ab Bakar,Hazlee Illias,Sameh Dabbak

doi:10.3390/en11040875

Abstract

In zinc oxide (ZnO) surge arresters, leakage current usually flows across the arrester under normal operating condition. Leakage current is one of the factors which contribute towards degradation of surge arresters and therefore, it is very important to monitor the condition of surge arrester. In this work, the behaviour of leakage current in a ZnO surge arrester during normal operation, under different voltage amplitudes, wetness and pollution conditions was analysed. An 11 kV surge arrester model in three-dimensional space was subjected to finite element analysis (FEA) to determine the leakage current under different conditions. The results from the FEA model were compared with the measurement results to validate the model that has been developed. From comparison between the measurement and simulation results, physical parameters of a surge arrester that influence the leakage current under different conditions of the surge arrester were identified from the model. Through this work, a better understanding of leakage current behaviour can be attained, which may help in condition monitoring analysis on surge arrester in electrical utilities.

Highlights

Transmission tower protection is important in protecting electrical equipment from damage [1,2].A natural phenomenon that usually happens on transmission towers is lightning overvoltage [3,4].One of the ways to protect the transmission line from lightning overvoltage is by installing surge arresters [5,6]
The comparison between measurement and simulation results of the surge arrester total leakage current under different applied voltage amplitudes is shown in Figure 6, while the resistive and capacitive leakage currents are shown in Figure 7, respectively
It was found that the leakage current increases when the applied voltage amplitude is higher, wetness is higher and pollution conditions are worse

Summary

Introduction

A natural phenomenon that usually happens on transmission towers is lightning overvoltage [3,4]. One of the ways to protect the transmission line from lightning overvoltage is by installing surge arresters [5,6]. A surge arrester limits the peak overvoltage to a level which will protect the instrument from damage [7]. The usual types of surge arresters are silicon carbide arresters with spark gaps, silicon carbide arresters with current limiting gaps and gapless metal oxide arresters. New developments in solid state technology have led to the development of non-linear resistors With this new technology, new class of surge arresters named zinc oxide (ZnO) surge arresters has been developed, which offer a lot of improvements and advantages over other arrester types [11,12]

Objectives

Methods

Results

Conclusion