Power supply system and direct-current converter thereof

A direct current (DC) converter, comprising:

• a non-isolated conversion module implemented based on a redundant structure and having a first buck converter, a second buck converter, and an output capacitor, wherein the first buck converter and the second buck converter are connected and commonly share the output capacitor;
• and
• an isolated conversion module having:
• a set of input terminals connected to output capacitor of the non-isolated conversion module;
• and
• a set of output terminals;
• wherein
• each of the first buck converter and the second buck converter of the non-isolated conversion module has a positive terminal and a negative terminal;
• the output capacitor has:
• a first end constituting a positive output terminal of the non-isolated conversion module, and connected to the set of input terminals of the isolated conversion module and the positive terminals of the first buck converter and the second buck converter;
• and
• a second end constituting a negative output terminal of the non-isolated conversion module, and connected to the set of input terminals of the isolated conversion module;
• the first buck converter has:
• a first diode having:
• an anode;
• and
• a cathode connected to the positive terminal of the first buck converter;
• a first inductor having two ends, wherein one of the two ends of the first inductor is connected to the second end of the output capacitor and the other end of the first inductor is connected to the anode of the first diode;
• and
• a first switch being a field effect transistor and having:
• a drain connected to the other end of the first inductor and the anode of the first diode;
• a source connected to the negative terminal of the first buck converter;
• and
• a gate connected to and controlled by a controller;
• and
• the second buck converter has:
• a second diode having:
• an anode;
• and
• a cathode connected to the positive terminal of the second buck converter;
• a second inductor having two ends, wherein one of the two ends of the second inductor is connected to the second end of the output capacitor and the other end of the second inductor is connected to the anode of the second diode;
• and
• a second switch being a field effect transistor and having:
• a drain connected to the other end of the second inductor and the anode of the second diode;
• a source connected to the negative terminal of the second buck converter;
• and
• a gate connected to and controlled by the controller.