Maintenance Scheduling Optimization for AC-DC Grid Based on Component Status under N-1 Contingencies

The joint optimization technology of maintenance scheduling with power outage with long-term unit commitment is a powerful support to the safe operation of AC-DC transmission grid. With respect to the splitting of single-ended component that may happen under the simultaneous action of branch maintenance and N-1 contingencies, this paper adds the in-service/out-of-service status variables of branch, generator, load and DC converter after maintenance and N-1 contingencies on the basis of the 0-1 decision variable of maintenance scheduling and unit commitment, and determines the association relationships between the variables above-mentioned, based on which the optimization model of the AC-DC grid maintenance scheduling is established, and linearizes the 0-1 status variables and non-linear constraints therein, to generate the mixed-integer programming model that is easy to be solved, to realize overall optimization of maintenance and power generation. Simulation is conducted by taking the improved IEEE 39-bus system as an example. The result shows that the proposed model and the algorithm can deal effectively with the load-generation imbalance caused by the component status change, enhance the reasonability and solvability of the maintenance scheduling based on N-1 contingencies, thus to upgrade the security of maintenance scheduling.