A DC capacitor voltage balance control method of cascaded multilevel STATCOM

In this paper, a method of energy self-balancing capacitor voltage waveform superposition based on equivalent area was presented, on the basis of which a control method of the capacitor voltage offset correction using the transposition of pulse, a rotation method of specific order selecting pulse, was proposed. This method can automatically modified the offset of capacitor voltage and the quality of the output current can't be affected. Simulation results show that the control method of cascaded multilevel STATCOM DC capacitor voltage balance is effective and feasible.