Direct current power factor correction in a direct current-to-direct current conversion system

A power converter system comprising:

• a first power converter configured to couple to a power source via an input of the first power converter, and configured to convert an input voltage provided by the power source to an intermediate voltage;
• a second power converter coupled at an input of the second power converter to an output of the first power converter and configured to convert the intermediate voltage to a regulated output voltage;
• a capacitor coupled at one of its terminals to an electrical node of the intermediate voltage;
• and
• a control subsystem configured to, based on one or more electrical parameters of the first and second power converters:
• control the second power converter to regulate the regulated output voltage at a substantially constant level;
• and
• control the first power converter to:
• control the intermediate voltage to maintain the intermediate voltage between a maximum voltage and a minimum voltage;
• and
• regulate an input current drawn from the power source at a substantially constant level.