With the continuous development of ultra-high-voltage direct current (UHVDC) transmission and new energy

the coupling relationship among AC

DC

and new energy in receiving power grids has become increasingly complex. Improper handling of a single AC fault can easily lead to systematic cascading failures

posing a serious threat to the safe operation of receiving power grids. To reveal the evolution mechanisms of cascading failures in receiving power grids

this paper first derives the causal relationships among key events

including DC commutation failure

high/low voltage ride-through and disconnection of new energy sources

and DC blocking. Subsequently

the impact of DC commutation failure on the low-voltage ride-through performance of new energy under different tie-line impedances and commutation failure prevention (CFPREV) control are analyzed. Finally

based on causal relationships

the evolution mechanisms and paths of cascading failure in receiving power grids are revealed. A complex receiving-end power grid model is built in PSCAD/EMTDC

and typical cascading fault simulation cases are conducted to verify the correctness of the proposed analysis of cascading failure evolution paths and mechanisms.