Isolated charging power supply

An isolated charging power supply includes: an alternating current power supply for providing alternating current power; a first rectifying circuit, used for rectifying the alternating-current power provided by the alternating-current power supply; at least two conversion circuits, connected in parallel, and the input ends of the conversion circuits being connected with the output end of the first rectifying circuit; at least two isolation transformers, wherein the input of one isolation transformer is correspondingly connected with the output of one conversion circuit; at least two second rectification circuits, wherein the input of one second rectification circuit is correspondingly connected with the output of one isolation transformer; and a switching circuit, connected between the two adjacent second rectifying circuits, and the switching circuit being used for switching a connecting structure between the second rectifying circuits between a series structure and a parallel structure. The output voltage r