Modeling and Analysis of Dual Comparison One Cycle Control for Single Phase Grid Connected Converters

The dual comparison one cycle control (DC-OCC) proposed in this paper regulates both the peak and valley of the current, unlike conventional one cycle control (C-OCC), which controls only the peak. This dual control approach effectively eliminates the steady-state DC offset, current distortion, and localized sub-harmonic instability issues observed in C-OCC. The DC-OCC structure is further extended to support bidirectional power flow, adjustable power factor operation, and STATCOM functionality. These enhancements are achieved with relatively simple modifications compared to existing methods in the literature. An average model of the DC-OCC is developed to analyze instability when the converter draws or injects lagging current into the grid. The controller’s effectiveness is validated through detailed simulation and experimental studies.