Power supply system and power supply method

A power supply system, comprising:

• a first power supply device comprising a first port, a second port, a third port and a fourth port, the first port of the first power supply device and the second port of the first power supply device electrically coupled to different power supply buses;
• the first power supply device further comprising:
• a first converter comprising a first port electrically connected to the first port of the first power supply device, a second port electrically connected to the third port of the first power supply device, and a third port electrically connected to the fourth port of the first power supply device;
• and
• a second converter comprising a first port electrically connected to the second port of the first power supply device, a second port electrically connected to the third port of the first power supply device, and a third port electrically connected to the fourth port of the first power supply device;
• a second power supply device comprising a first port, a second port, a third port and a fourth port, the first port of the second power supply device and the second port of the second power supply device electrically coupled to different power supply buses;
• the second power supply device further comprising:
• a third converter comprising a first port electrically connected to the first port of the second power supply device, a second port electrically connected to the third port of the second power supply device, and a third port electrically connected to the fourth port of the second power supply device;
• and
• a fourth converter comprising a first port electrically connected to the second port of the second power supply device, a second port electrically connected to the third port of the second power supply device, and a third port electrically connected to the fourth port of the second power supply device;
• and
• a first load comprising a first receiving port electrically coupled to the fourth port of the first power supply device, and a second receiving port electrically coupled to the third port of the second power supply device.