A hybrid multilevel inverter for shunt active filter using space-vector control

In this paper, a current active power filter using a hybrid asymmetric multilevel inverter is presented and analyzed. The control proposed is based on a vector-control technique, generating an optimized switching pattern. The hybrid multilevel inverter increases the voltage levels number, reducing the harmonics associated to the commutation frequency. The hybrid multilevel inverter is structured by two cascaded-inverters, and the DC link voltage between the stages has the relation 1:3, generating 9 voltage levels. The signal reference is generated using a variant of the single-phase d-q Theory, allowing a fast transient response and stability. Simulated waveforms prove the viability of the control scheme and the multilevel active current filter proposed.