Power converter

A power converter comprising:

• an input port and an output port, wherein the power converter is configured to receive an input voltage through the input port and output an output voltage through the output port;
• and
• N conversion units, wherein N is an integer greater than 1, each of the N conversion units comprises a sub input port, a sub output port and a maximum stress rating, the sub input port of each of the N conversion units is connected with the input port to receive the input voltage, the sub output port of each of the N conversion units is connected with the output port, the maximum stress rating is a maximum stress tolerable by any component within the corresponding conversion unit, wherein when the input voltage of the input port is greater than the maximum stress rating of any one of the N conversion units, the sub input ports of the N conversion units are connected in series.