Speed Effect of Moving Electrode on Break Arc in LVDC Systems

This paper introduces a low-voltage direct current system as a means of supplying power to electrified isolated regions. Specifically, this paper advocates for the implementation of an extra-low-voltage direct current (ELVDC) infrastructure with a capacity of 120 V and 800 W or lower, aligning with the Tier 2 and Tier 3 levels of the World Bank Multi-Tier Framework classification system. The focus lies in devising guidelines for the secure utilization of household copper electrode-type socket outlets and plug or contact-type switches, commonly employed in conventional alternating current systems, during the establishment of ELVDC facilities catering to power supply in electrified isolated areas. This paper experimentally investigates the arc characteristics of socket-outlet plug-type electrodes in various power circuit environments with power supply voltages below 200 V and load powers below 1000 W. It aims to identify statistical trends on the basis of the opening velocity of the electrode and analyze the effects of the opening velocity on arc duration and arc extinction distance. On the basis of the experimental results, it derives and compares the arc-safe operating regions that maintain the equal arc extinction distance for various opening velocities in relation to supply voltage and load power levels. Additionally, it presents the arc thermal energy operating regions that indicate the relationship between the opening velocity and arc duration time, providing a safe relationship between supply voltage and load power to prevent arc accidents. The analytical findings presented in this paper are intended to be applicable to the design and safe operation of crucial components, such as socket-outlets and plug, or contact-type wall-mount lighting switches, within ELVDC facilities tailored for households with a capacity of 120 V and 800 W or less.