Power Supply Management Method, Device, and System

A power supply management method implemented by a level-1 powered device, the power supply management method comprising:

• performing detection on all level-2 power supply ports of the level-1 powered device to determine a first level-2 power supply port that is valid;
• sending a power-on request to a power sourcing equipment, wherein the power-on request comprises a first port identifier of the first level-2 power supply port such that the power sourcing equipment is configured to determine, from the first level-2 power supply port, a second level-2 power supply port that is allowed to be powered on, wherein the level-1 powered device is coupled to a level-1 power supply port of the power sourcing equipment and configured to extract electricity from the level-1 power supply port;
• receiving a power-on instruction from the power sourcing equipment, wherein the power-on instruction comprises a second port identifier of the second level-2 power supply port, and wherein the second level-2 power supply port is the first level-2 power supply port;
• and
• powering on, according to the power-on instruction, the second level-2 power supply port.

A power sourcing equipment, comprising:

• a power sourcing equipment (PSE) chip;
• a level-1 power supply port coupled to the PSE chip;
• and
• a processor coupled to the PSE chip and the level-1 power supply port and configured to:
• receive a power-on request from a level-1 powered device using the level-1 power supply port, wherein the power-on request comprises a first port identifier of a first level-2 power supply port that is valid in the level-1 powered device, and wherein the level-1 powered device is coupled to the level-1 power supply port and configured to extract electricity from the level-1 power supply port;
• determine, based on the power-on request and an outputtable power of the power sourcing equipment, a second level-2 power supply port that is allowed to be powered on in the level-1 powered device;
• and
• send a power-on instruction to the level-1 powered device using the level-1 power supply port, wherein the power-on instruction comprises a second port identifier of the second level-2 power supply port, and wherein the power-on instruction instructs the level-1 powered device to power on the second level-2 power supply port.

A powered device, comprising:

• a plurality of level-2 power supply ports;
• a power extraction port coupled to a power sourcing equipment;
• a detection control circuit coupled to the level-2 power supply ports and configured to:
• perform detection on the level-2 power supply ports;
• and
• send a power-on request to the power sourcing equipment using the power extraction port, wherein the power-on request comprises a first port identifier of a first level-2 power supply port that is valid in the level-2 power supply ports;
• a power supply control circuit coupled to the level-2 power supply ports and configured to:
• receive a power-on instruction from the power sourcing equipment using the power extraction port, wherein the power-on instruction comprises a second port identifier of a second level-2 power supply port allowed to be powered on, and wherein the second level-2 power supply port is the first level-2 power supply port;
• and
• power on, according to the power-on instruction, the second level-2 power supply port;
• and
• a powered device (PD) chip coupled to the power extraction port and configured to extract electricity from the power sourcing equipment to supply electricity to the detection control circuit and the power supply control circuit.