The unscheduled outage restoration strategy of active distribution network is studied considering the risk

cost and gain factors in the recovery process of integrated distribution network. A distribution network restoration risk model is developed by assessing the execution risk of restoration sub-process and the operation risk of transitional power grid. On this basis

a multi-objective optimization model considering gain and cost of distribution network restoration is established based on the monetary dimension. The restoration strategy of distribution network is optimized by a heuristic algorithm with the greedy policy

which is improved by no aftereffect algorithm. The simulation results show that the proposed strategy considers the uncertain risk of distribution network restoration and restore the blackout area as much as possible on the premise of ensuring the maximum economic gains

accordingly improving the power supply reliability and the economy of restoration process.