Key Laboratory of Modern Power System Simulation and Control & Renewable Energy Technology, Ministry of Education (Northeast Electric Power University), Jilin 132012, China

In order to quickly and accurately quantify the influence of uncertainty of wind power output on power flow distribution of AC/DC power system, a holomorphic embedding probabilistic power flow calculation method of AC/DC power system based on polynomial chaos expansion (PCE) is proposed. Firstly, the optimal orthogonal basis function is selected according to the probability distribution characteristics of wind power output, and the PCE expression approximating the probability distribution characteristics of wind power output is constructed. Secondly, the PCE expression is introduced into the holomorphic embedding power flow equation of AC/DC power system, and the holomorphic embedding probabilistic power flow calculation model of AC/DC power system based on PCE is constructed. Thirdly, the holomorphic embedding probabilistic power flow model is transformed into a high-dimensional deterministic holomorphic embedding power flow model by Galerkin projection. Then, with the deterministic holomorphic embedding power flow model solving method, the transformed high-dimensional deterministic holomorphic embedding power flow model is solved, and the probability distribution characteristics of power flow in AC/DC power system are calculated according to the obtained PCE approximation coefficient. Finally, the accuracy and effectiveness of the proposed method are verified by the modified PJM 5-bus, IEEE 30-bus and IEEE 118-bus AC/DC test systems.

This work is supported by National Natural Science Foundation of China (No. 52077029, No. U22B20105, No. 52377083).