Method for evaluating electric power system risk based on fault pre-scanning

The invention discloses a method for evaluating the electric power system risk based on fault pre-scanning. The method comprises the steps that firstly, according to the current structure of an electric power system and a planning scheme, a corresponding planning scheme model is established; secondly, based on device data and a power grid structure, predicted faults and the possibility of the predicated faults of a power grid are analyzed, and then a pre-scanning fault set is formed; thirdly, through the risk state based on direct-current power flow, screening and ordering are conducted on the predicated fault set, so that a fault state list is formed; fourthly, all power flow corresponding to the faults in the list is worked out, and for the fault with the power flow out of range, the consequence of the fault is load loss; fifthly, according to the load loss of the fault states and the possibility of the fault states, the system risk indicator is worked out; sixthly, according to the system risk indicator, the system weak link is found out. By the adoption of the method for the evaluating electric power system risk based on fault pre-scanning, analysis of all the fault sates in the fault set through alternating-current power flow is avoided, so that the calculation amount of follow-up alternating-current power flow analysis and risk indicator processing is greatly reduced, and a large mount of calculation time is saved.