Reliability assessment method for power grid multi-link system

The invention discloses a reliability assessment method for a power grid multi-link system. According to the method, influences of a power transmission network on the reliability of a power distribution network are quantified through the equivalence of the reliability of a load and the reliability of a power supply, the limitation of the assumption that traditionally the reliability of a traditional power distribution network is that the power supply is completely reliable is broken, and a calculation result accords with engineering practice of the power grid; in the method, a loop is used as the basic unit of a reliability assessment of the power transmission network, and a preconceived accident set is further formed, so that the system condition number in the preconceived accident set is substantially reduced, and the statistic analysis of engineering data of the reliability is facilitated. The reliability assessment method can be used for analysis of the sensitivity of reliability indexes to reliability parameters and enhancement measures relevant to the power transmission network or the power distribution network, and consequently planning, operation and maintenance of a power supply enterprise can be guided.