Experimental studies of material erosion rates in DC circuit breaker

Author: Roman Vogt
Year: 2024
Supervisor: Mohamed F. M. Abdelfattah

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 environmentally 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 conducted 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 reveal 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.