Experimental Comparison of Digital Implementations of Single-Phase PFC Controllers

This paper presents the design and the digital implementation of three controllers for a single-phase power factor corrector (PFC). Based on an averaged system model, an adaptive nonlinear control strategy is first designed, followed by a digital redesign of the standard cascaded linear controller and a notch-filter-based variant. All three controllers have been verified via simulation in Simulink using a continuous time plant model and a discrete time controller. Real-time implementation is performed on an experimental testbed utilizing a rapid prototyping tool. The three controllers are experimentally compared for steady-state performance and transient response. It is shown that the nonlinear controller gives a better steady-state performance, whereas the linear strategy and the notch-filter-based variant have a faster dynamic response. Furthermore, although the notch-filter-based linear design shows promise in simulation, practical difficulties degrade its experimental performance. Performance metrics are tabulated for easy comparison.