Improvement in the quality of load current by various controlling techniques in hybrid power filter for harmonic compensation and resonance suppression

A new hybrid power filter by employing an active filter and C-type filter had been proposed in order to reduce the rating of harmonic compensator and for resonance suppression. However, the resultant waveform shows noticeable peaks thereby making the current non-linear. Thus, the harmonic content in the power system considerably increases. Based on the hybrid power filter, this paper presents a new and improved converter in which the peaks can be reduced to the maximum possible extent by using a PID controller. The new improved hybrid filter is implemented reducing the peaks and modifying the signal close to sinusoid by the PID control method. Also, the quality of the load current waveform will be compared on the basis of other controlling techniques. Simulations for the harmonic suppression and control-loop response are implemented and the results confirm the theoretical analysis. It proves that this kind of topology is effective on the harmonic compensation, elimination of resonance and in the modification of the load current to become approximately sinusoidal.