Charging control method and charging system capable of tracking maximum efficiency

A charging system, comprising:

• a power delivery unit, which is configured to operably convert an input power to a DC power;
• a detachable cable, which is configured to operably receive the DC power, and generate a bus power;
• and
• a charging circuit, which is configured to operably convert the bus power to a charging power to charge a battery in a charging period;
• wherein the charging circuit includes an inductive switching power converter and a capacitive switching power converter, wherein the inductive switching power converter is configured to convert the bus power into a first power, and the capacitive switching power converter is configured to convert the first power into the charging power;
• wherein based on a relationship between the DC power and the charging power, the inductive switching power converter is configured to selectively operate in either a first regulation mode or a first short circuit conduction mode, and the capacitive switching power converter is configured to selectively operate in either a second regulation mode or a second short circuit conduction mode;
• wherein
• in the first regulation mode, the inductive switching power converter regulates the first power to a predetermined target;
• in the second regulation mode, the capacitive switching power converter regulates the charging power to a predetermined target;
• in the first short circuit conduction mode, the inductive switching power converter short-circuits the bus power to the first power;
• and
• in the second short circuit conduction mode, the capacitive switching power converter short-circuits the first power to the charging power;
• wherein the power delivery unit is configured to adaptively adjust the DC power based on power conversion efficiency feedback to track a maximum power conversion efficiency of the charging system, in combination with selectively operating the inductive switching power converter in either the first regulation mode or the first short circuit conduction mode, and operating the capacitive switching power converter in either the second regulation mode or the second short circuit conduction mode, based on the DC power and the charging power.