Numerical Analysis on the Short-circuit Withstanding Performance of Busbar System in LV Switchgear

The short-circuit withstanding performance of busbar system is one of the most important safety indexes for low-voltage (LV) switchgear. The resonance characteristics, short-circuit displacement, and stress concentration of four typical busbar system arrangements are numerically analysed in this study. First, modal analysis is used to calculate the vibration modes and natural frequencies of the busbar systems. The influence of span length and phase-to-phase distance is discussed and thresholds for resonance prevention are given. Then, electromagnetic-structural coupled models are built to simulate the short-circuit mechanical response. The time-varying displacement and stress are obtained and the dynamic stability of typical arrangements is compared. The proposed results can provide theoretical reference for the dynamic stability design of busbar system in LV switchgear.