Hybrid boost-bypass function in two-stage converter

A power converter, comprising:

• a boost-bypass converter, including:
• a boost inductor coupled between an input of the boost-bypass converter and an output of the boost-bypass converter, wherein an input voltage of the boost-bypass converter is a rectified input line sinusoidal voltage coupled to be received at the input of the boost-bypass converter;
• a bypass diode coupled between the input of the boost-bypass converter and the output of the boost-bypass converter;
• and
• a boost switching element coupled to the boost inductor;
• and
• a second-stage flyback converter cascaded with the boost-bypass converter, wherein the second-stage flyback converter includes an input coupled to the output of the boost-bypass converter, wherein the second-stage flyback converter further includes:
• an energy transfer element coupled between the input of the second-stage flyback converter and an output of the second-stage flyback converter;
• a flyback switching element coupled to the energy transfer element;
• and
• a controller coupled to control switching of the flyback switching element to regulate a transfer of energy from the input of the second-stage flyback converter through the energy transfer element to the output of the second-stage flyback converter, wherein the controller is further coupled to the boost switching element, wherein the controller includes logic that when executed by the controller causes the controller to perform operations including:
• activating the boost switching element during a first interval in each line half cycle of the input voltage to boost an output voltage at the output of the boost-bypass converter;
• deactivating the boost switching element during a second interval in said each line half cycle of the input voltage, wherein the output voltage of the boost-bypass converter is coupled to drop towards the input voltage during the second interval while the output voltage of the boost-bypass converter is greater than the input voltage;
• and
• controlling the output voltage of the boost-bypass converter to follow the input voltage during a third interval of said each line half cycle of the input voltage, wherein energy is transferred between the input and the output of the boost-bypass converter through the bypass diode during the third interval.