Fractional-Order Multiperiodic Odd-Harmonic Repetitive Control of Programmable AC Power Sources

In this article, a generic plug-in fractional-order multiperiodic odd harmonic repetitive control (FOMP-OHRC) scheme is proposed to provide a simple high-performance control solution to the programmable ac power sources. The proposed FOMP-OHRC scheme evolves from the plug-in multiperiodic OHRC scheme, which can take both advantages of the multiperiodic OHRC controller and the feedback controller—the feedback controller provides fast response and good robustness, and the plug-in multiperiodic OHRC controller offers accurate compensation of the multiperiodic signals. The stability criteria and the control gain tuning rules have been developed to facilitate the analysis and synthesis of the plug-in multiperiodic OHRC scheme. More critically, in order to exactly compensate the multiperiodic signals with unavoidable fractional periods in practice, the multiperiodic OHRC controller is transformed into the FOMP-OHRC controller by substituting the fractional period elements with the Lagrange-polynomial-based interpolation filters. Experimental results indicated the programmable ac power source with the proposed FOMP-OHRC can generate required multiperiodic voltages with high accuracy, fast transient response, and good robustness.