DSP-based adaptive repetitive control of a PWM inverter for UPS with very low harmonic distortion

Abstract

An adaptive repetitive control scheme is proposed and applied to the control of a PWM inverter used in high performance ac power supply. The proposed control algorithm can adaptively compensate waveform distortion resulted by periodic disturbances in an ac power supply. Pole assignment with state feedback control method has been employed as the tracking controller for transient response improvement. The proposed control scheme has been realized using a single-chip digital signal processor TMS320C14 from the Texas Instrument. A 2 kVA ac power supply has been constructed to verify the proposed control scheme. Simulation and experimental result show that the DSP-based adaptive repetitive controller can achieve both good dynamic response and low THD under large load disturbances and plant uncertainties.