Molecular Dynamic Simulation of the Effect of Initial Surface Temperature on Arc Erosion Due to Ion Bombardment

This study focuses on the effects of initial surface temperature on arc erosion caused by ion bombardment. The simulation results show that higher surface temperature leads to a greater number of lost Cu atoms and an increased size of the erosion crater. This is due to the ability of the incident ions to have a greater sputtering yield at higher temperatures. Moreover, the Cu atoms tend to agglomerate and form clusters after ion bombardment while leaving the surface

Electrical Erosion Resistance of Graphene Reinforced Cu-W Circuit Breaker Contact Materials under 5 kA Arc

This work integrates experimental and MD simulation approaches to study the role of graphene in G-Cu-W composites. Arcing tests were conducted on G-Cu-W and Cu-W contact samples under a 5kA peak current. Experimental results show that adding graphene leads to a lower surface roughness of the sample following arcing. MD simulation results indicate that the G-Cu-W model exhibits a smoother surface and fewer lost metal atoms than the Cu-W model due to the protective effect of graphene layer

Understanding the Temperature Profile of the IEC TS 62332-1 Dual-temperature Ageing Cell

This paper discusses the challenges faced during the development of a dual-temperature test cell based on IEC technical specification TS 62332-1 to evaluate the ageing performance of transformer insulation systems. A dual-temperature test cell was built based on IEC TS 62332-1 and the performance of the test cell was investigated accordingly. Apart from measuring the conductor and the top liquid temperatures, additional temperature measurements were conducted in other locations including hot solid insulation, cold solid insulation, liquid immersion heaters and test cell surface. Temperature distribution inside the dual-temperature test cell is then analyzed. The results indicate the importance of location of top liquid temperature thermocouples and its effect on the overall temperature distribution. Some additional aspects for maintaining consistency between different test cells are also discussed.</p

Evaluation of Bubble Formation in Transformer Insulation Systems - a Step Forward

Bubble formation in transformers could result in severe consequences leading to power outages and huge financial losses. There is an increased risk of bubble formation in the future due to increasing load demand and much higher loading fluctuations. The bubble formation process in transformer insulation has been studied for decades and the water content in the paper has been addressed as the most influential impact parameter. However, results from the most common insulating material combination of Kraft paper and mineral oil vary widely and a meaningful comparison for other parameters or insulating material combinations is challenging. This paper presents the development and verification of a simple test setup that can be used to study various impact factors on the bubble formation process with a high degree of confidence.</p

Electrical Erosion Resistance of Graphene Reinforced Cu-W Circuit Breaker Contact Materials under 5 kA Arc

This work integrates experimental and MD simulation approaches to study the role of graphene in G-Cu-W composites. Arcing tests were conducted on G-Cu-W and Cu-W contact samples under a 5kA peak current. Experimental results show that adding graphene leads to a lower surface roughness of the sample following arcing. MD simulation results indicate that the G-Cu-W model exhibits a smoother surface and fewer lost metal atoms than the Cu-W model due to the protective effect of graphene layer.</jats:p