Current harmonics injected in three-phase power systems by chopper controlled DC loads

This study explains the mechanism of generation of non-characteristic harmonics in three-phase systems supplying dc chopper controlled loads. The results presented will enable designers to predict the current harmonic spectrum on ac lines and to evaluate the impact of chopper load upon the converter transformer and the distribution system. The results published will assist in the optimization of the LC input filter and to determine the best switching frequency strategies.