The blackout prevention research against natural disasters has been limited to a single disaster so far

to the neglect of the enhancement effects between intercurrent disasters. As natural disasters often cause power system cluster faults

on-line tracking of external environment changes and effective early warning are needed to guard against blackouts caused by high risk intercurrent natural disasters with low probability. Therefore

a new line of risk analyzing thought as well as a scheme for cluster faults due to intercurrent natural disasters is proposed. On one hand

fault probability models should be developed and the risk of power grid branches under intercurrent natural disasters calculated and on the other

the interactive influence of multiple natural disasters should be considered

potential faults should be screened on line

power system operational security and stability analyzed

and decision support given.