Comparison of direct power control with hybrid approach on 3-Phase 4-wire active power filter between p-q-0 and p-q-r power theory

New hybrid control approach of the pq control theory applied to the 3 phase 4 wire active power filter is proposed. This technique inherits not only the simplicity of the conventional direct power control but also offers a good dynamic response in active filtering. In this paper, the proposed control method is implemented for two different instantaneous power theories, i.e. p-q-0 and p-q-r power theory. The comparison between them is oriented around the harmonic contain of the source current for each method and the unbalanced current index. The analysis is verified using the PSIM simulation software.