Single phase high power factor rectification is the most frequently accomplished using a boost converter. The input current shaping approach results in low line currents harmonic distortion and a power factor close to unity at the interface between the ac line and the rectifier. Various techniques are available for active current shaping, average current mode control, nonlinear control and one cycle control. Most of them are now supported by dedicated integrated circuits. Average-current-mode control is the regular control where the inductor current is forced to follow the input voltage. Recently nonlinear phenomena have been obvious in AC/DC converters which results in unstable regime such as period doubling and chaos. During these operating regimes, the input current distorts and therefore, breaks the operation of PFC converters. In this book, a study for stability for the three practical controls of boost PFC converter is introduced. Each technique has been tested to determine the practical limitation for stable regions. Design guidelines are made clear for stable operation in the examined control techniques. Experimental results confirm simulation with good matching.