Experimental studies of material erosion rates in DC circuit breaker

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Journal Title

Journal ISSN

Volume Title

Sähkötekniikan korkeakoulu | Master's thesis

Date

2024-08-19

Department

Major/Subject

Electrical Power and Energy Engineering

Mcode

ELEC3024

Degree programme

AEE - Master’s Programme in Automation and Electrical Engineering (TS2013)

Language

en

Pages

104

Series

Abstract

The transition to direct current (DC) in applications such as photovoltaics and batteries presents a significant challenge due to the absence of natural zero crossings in DC, making it difficult to interrupt the current and extinguish arcs. The environ-mentally friendly Arc Squeeze Method (ASM) is a promising and cost-effective solution, which elongates and squeezes the arc between polymeric surfaces. However, the material degradation limits the number of successful interruptions, posing a critical problem. Although there have been studies on ASM and corresponding materials, these studies typically only examine a few interruptions. In practical applications, circuit breakers need the ability to withstand hundreds of interruptions. Additionally, the impact of systematically changing circuit parameters on the electrical lifespan has not been investigated. This study aims to address this knowledge gap by examining the influence of electrical circuit parameters on the lifespan of insulating materials and its performance during repeated arc interruptions. All tests were con-ducted at a constant voltage level (1000 Volt) and three different materials were compared using a newly built test setup in the laboratory. The empirical results re-veal key performance parameters of the materials and indicate that higher current levels result in fewer successful interruptions and that the required arc length significantly depends on the system voltage.

Description

Supervisor

Lehtonen, Matti

Thesis advisor

Nohlert, Johan

Keywords

erosion, arc, DC, squeeze, ablation, gassing

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Citation