Analysis and Verification of Arc Characteristics in Low Voltage DC Systems

The technology of low voltage DC power supply can improve the economy and shock safety protection performance of the system, and has become a new hot topic in the field of power supply research. However, its fire safety hazards still need to be explored urgently. Due to the lack of zero crossing, DC arc is more difficult to extinguish than AC arc, and is considered an important fire hazard in DC systems. The characteristics of DC arc and the influence of inductance and capacitance on it under actual circuit conditions are first analyzed in this article. Based on this, combined with the characteristics of low voltage DC system applications, a method of achieving “natural extinction” of DC arc by relying on DC filter capacitors is proposed, and its parameter constraints are studied. Theoretical derivation and experimental verification indicate that, through reasonable design of circuit parameters, under certain conditions, the arc in the low voltage DC system has the characteristic of “natural extinction”, which can greatly reduce the dependence on arc detection devices, reduce system and equipment costs, and better balance the safety and economic requirements of the low voltage DC system.