Improved Arc Interruption of High Voltage SF&amp;lt;sub&amp;gt;6&amp;lt;/sub&amp;gt; Circuit Breakers Using Modified Mayr’s Differential Equation

Okpura Nseobong I

doi:10.11648/j.ijssam.20170201.13

Abstract

The study of arc interruption is very essential in high voltage circuit breakers since arc extinction must be achieved in the shortest possible time for effective protection of the power system. This paper presents some conventional arc models used in the research of interaction between switching arc and circuit during the interruption process of high voltage circuit breakers. It goes ahead to develop a model that is current dependent with a constant time parameter that helps to improve the process of arc interruption in high voltage SF6 circuit breaker. The simulation results show that the model has the capability of reducing the arc interruption time by completely extinguishing the arc current almost instantaneously.

Highlights

A circuit breaker is a device that do interrupt faults or abnormal currents and at the same time functions as a switch
Circuit breakers have to be accessible for inspection and maintenance, it is required that there should be a provision for the separation of the breaker from the live parts by means of isolating switches
SF6 gas is widely used in electrical equipment such as high voltage metal clad switchgear, voltage metal enclosed cables, circuit breakers, capacitors, bushings, current transformers, etc

Summary

Introduction

A circuit breaker is a device that do interrupt faults or abnormal currents and at the same time functions as a switch. SF6 gas is widely used in electrical equipment such as high voltage metal clad switchgear, voltage metal enclosed cables, circuit breakers, capacitors, bushings, current transformers, etc. It is liquefied at certain low temperature, liquefaction temperature increases with pressure [2]. As regards SF6 circuit-breaker, even after contact separation current will continue to flow At this point the current flows through the arc which has plasma that comprises of ionized SF6 gas. The cooling power in the modified Mayr arc model is current-dependent [6, 10]. The arc interruption is a function of the electrical power input

Mayr’s Mathematical Model of the Arc

Derivation of the Modified Mayr Model

Simulation Results and Discussion

Conclusion