| Abstract |
The hybrid AC/DC power system is favored because of its huge energy transmission capacity and excellent steerability. However, the real system is large in scale and the inner dynamics interaction and coupling are intricate, which introduces a series of stability issues for the system operation. To investigate AC/DC interaction dynamics, an MMC-based hybrid power system model is established in the state space. The model considers the detailed dynamics of both AC and DC, and their interaction, thus it can be used for AC/DC interaction study, and offer a more precise stability assessment result than either AC power system model or MMC converter model. After the verification in MATLAB/Simulink, The interaction is studied thoroughly by the proposed model, which clearly identifies the harmonic coupling between MMC and traditional power systems. The small signal stability gaps of different systems are also compared. Case results prove that the reduced-order model can be deployed to assess stability efficiently under specific circumstances. The interaction causes extra harmonics in AC affecting the hybrid system stability. |
