DC-side shunt active power filter for line commutated rectifiers to mitigate the output voltage harmonics

This paper proposed a shunt active power filter connected to a 6-pulse converter DC-side to compensate converter output voltage harmonics. It is controlled to inject the compensation current necessary to generate harmonic voltages across an inductor connected in series with the load to achieve a load voltage with a reduced ripple factor. Moreover, the load current is indirectly compensated. The compensation simulation results are for a medium line voltage of 3.3 kV. Finally, practical results are included using a scaled down prototype 6-pulse converter to verify the derived expressions and the performance of the proposed control system. Harmonic spectrum analyses are presented for the simulation and practical results to validate compensation effectiveness.