Three-level APF control strategy based on the double sampling timing comparison

High frequency harmonics generated by active power Alter (APF) play a negative role on the power quality of grid. To eliminate the impact without reduction on harmonic compensating effectiveness, this paper proposed a three-level diode-clamped APF topology. Besides, the double sampling and the neutral voltage balancing technology based on the short vector switching were utilized to accomplish the timing comparison control strategy proposed in this paper. Moreover, the influence of feedback current sampled position and the system delay on APF performance were also analyzed in this paper. Finally, an experimental prototype was established, and the whole scheme was validated by the experimental results.