Bifurcation analysis of pre-regulator PFC boost converter

Boost PFC converter with average-current-mode control is the most suitable structure to draw input current with a near unity power factor. The main feature of this circuit is the bulk capacitance and using two control loops and multiplier in control circuit that assures its nonlinearity. In conventional power electronics, stability is interpreted as a condition in which the system operating in the expected periodic regime. Then, all those subharmonic, quasi-periodic, period doubling, chaos considered undesirable and should be avoided. Therefore this is unstable regimes, even though perfectly predictable. In this paper, the boost PFC converter stability is discussed from the bifurcation point of view. Two nonlinear phenomena are counted in PFC circuit, period doubling bifurcation and chaos. This paper addresses a study for the most important phenomena in PFC converter, period doubling bifurcation. A new proposed technique for understanding and analysis this phenomenon is introduced depending on the capacitor storage energy. The storage energy on the output capacitor is a signal for the output voltage and the input current. Steady state operation means zero storage energy; charge and discharge energy are equal every one-line cycle. Zero storage energy is achieved in double-line cycles instead of one in period doubling bifurcation case. As the load lessens, a required extra storage power is needed to achieve the significant increase in the output voltage. If the PFC system can provide this extra energy, the operation will reach stability with new zero-storage energy else the system will have double-line zero energy that is period doubling bifurcation. The details of the proposed method are introduced and its validity is proved with simulation, experiment and mathematical analysis.