Design and Implementation of Single-Phase Asymmetric Multilevel STATCOM

The design and control of the static synchronous compensator (STATCOM) based on the single-phase asymmetric cascaded H-bridge (ACHB) inverter with different dc voltage values are carried out in this paper. In this paper, the synchronous reference frame (SRF) proportional-integral controller is employed to control the grid current of the ACHB-STATCOM to achieve reactive power compensation. To enhance system stability, an active damping strategy based on the capacitor-current feedback loop is devised to attenuate the resonance of LCL filter. Moreover, the hybrid modulation scheme is adopted for the multilevel inverter to generate 19 levels at the output voltage. A reduced-size STATCOM prototype has been built and the experimental results are provided under the inductive and capacitive scenarios, which confirms the effectiveness of the STATCOM based on the designed circuit and the presented control and hybrid modulation scheme.