Abstract:

On the basis of the analysis of the main differences in mechanical interlocking between the new and old versions of GB/T 14048.11—2024 Low-voltage switchgear and controlgear-Part 6-1: Multiple function electrical apparatus-Transfer switching equipment,and considering the mechanical interlocking structure of a certain type of high-capacity transfer switching equipment(TSE),when the operating power switch Ⅰ and power switch Ⅱ are simultaneously closed in the off position,there is a phenomenon that the moving and fixed contacts are instantaneously connected and then tripped.A dual-interlocking improvement scheme is proposed,which adds a spindle interlock on the basis of the original tripping interlock.Through simulation analysis,it is verified that the proposed improvement scheme can effectively eliminate the instantaneous simultaneous connection phenomenon,enhance the application reliability of TSE and the feasiblity of practical engineering applications.

Key words: transfer switching equipment(TSE), trip interlock, spindle interlock, dual interlock