Triangular H-bridge cascading STATCOM with harmonic optimization adjustor

The invention provides a triangular H-bridge cascading STATCOM with a harmonic optimization adjustor. The triangular H-bridge cascading STATCOM with the harmonic optimization adjustor comprises a main circuit and a control circuit, wherein the main circuit is of a triangular structure formed by cascading of H-bridge units. The three peaks of the triangular structure are connected to a three-phase power grid in parallel. The control circuit comprises the harmonic optimization adjustor and an STATCOM controller. According to the triangular H-bridge cascading STATCOM with the harmonic optimization adjustor, reactive power compensation, current unbalanced compensation and harmonic compensation can be carried out on the power grid. When the three-phase (a, b and c) harmonic contents of loads are not equal, the harmonic effective values of the phase ab, the phase bc and the phase ca of the triangular STATCOM are approximate as far as possible, and the maximum harmonic effective values of the phase ab, the phase bc and the phase ca of the triangular STATCOM are the minimum, so that the installed capacity of the STATCOM is saved to the greatest extent.