Load adaptability of hybrid harmonic reduction method at DC-link of series-connected multi-pulse rectifiers

To verify the harmonic suppression capability of a series-connected 36-pulse rectifier and to improve the load adaptability of its harmonic injection circuit, a reliable selection method for the DC-side output capacitor of the rectifier is proposed. The sufficient and necessary conditions for ensuring the rectifier can operate under the 36-pulse rectification state is summarized, which is the basis for selecting capacitance values under different load types. After using the proposed selection method for the output capacitors, simulation and experimental results indicate that the hybrid harmonic suppression circuit has good performances under a resistive load, a resistive–inductive load, or a load mutation.