Harmonic State Space Modeling of Cascade STATCOM and Characteristic Analysis

With the large-scale application of STATCOM in medium and high voltage grid, high-frequency harmonic oscillations generated by its interaction with grid impedance and other factors have emerged in actual operation of power systems. For the analysis of harmonic characteristics of Cascade STATCOM, this paper establishes a harmonic state space (HSS) model of the Cascade STATCOM by considering its main control, phase-to-phase voltage control, and internal voltage control. By comparing the model's calculation results with simulation results, the accuracy of the model and the harmonic characteristics of the Cascade STATCOM under grid balance conditions are verified.