A DSP-based single-phase AC power source

This paper presents the development of a single-phase ac power source, which is capable of generating high-quality sinusoidal waveforms with adjustable amplitudes and frequencies over a wide range. Moreover,various types of arbitrary waveforms can also be generated. The system consists essentially of a well-controlled single-phase pulsewidth modulated inverter. To perform tight closed-loop control of the inverter, a digital controller based on the generalized predictive control approach has been developed. The controller gains are determined by minimizing a cost function that reduces both the tracking error and the control signals. To evaluate the proposed approach, a digital-signal-processor-based experimental prototype has been constructed. Experimental results under various loading conditions have demonstrated that the system performs well.