Stabilizing Technique for AC-DC Boost PFC Converter Based on Time Delay Feedback

It is well known that the ac-dc power factor correction (PFC) boost preregulator can present instability at the line frequency. This nonlinear phenomenon can jeopardize the system performances by increasing the total harmonic distortion and decreasing the power factor. In this brief, a new stabilizing technique is applied using time delay feedback when the system exhibits slow-scale instability under a traditional controller. First, the technique is applied to the averaged model. The results are then validated by numerical simulations using power simulator package. An analytical expression for the stability domain is also provided. It is proven that the proposed technique introduces many advantages to the most and widely used average current mode control through widening the stability region of the PFC converter. Moreover, this technique can also bring the same advantages to other existing commercial control methods for boost and other PFC topologies.