Robust Optimized Unit Commitment Considering Frequency Security Constraints Under N-k Contingencies

To achieve the goals of carbon neutrality and peak carbon dioxide emissions, new energy power generation will gradually occupy a dominant position in the energy structure of China, and large amount of grid-connected new energy generating units reduces inertia level and anti-interference ability of power grids. To improve the frequency regulation ability of low inertial system, considering frequency regulation characteristics of wind power units a frequency response model for thermal power generating and wind power generating units, which possessed inertial response capability and primary frequency modulation capability, was built, and the expression of the lowest frequency was deduced. In traditional unit commitments, the frequency security constraints, in which the uncertainty of unit fault was taken into account, was considered, and a two-stage robust optimization model taking frequency security constraint into account under N-k faults was established and solved by Benders decomposition method. Finally, the reliability test system based on IEEE-RTS79 was utilized for analysis on computing example. The effectiveness of the established model is verified.