Lightning protection radio remote unit, distributed base station, lightning protection system and method

A distributed base station lightning protection system, comprising:

• a radio remote unit (RRU) comprising an isolation power supply and a working circuit, wherein the isolation power supply is configured to receive a power supply from a power supply system and convert the power supply into a working power supply available to the working circuit;
• and
• a shielded cable comprising inner conductors and a shield layer, wherein
• the isolation power supply comprises a primary circuit and a secondary circuit, the primary circuit is connected to the inner conductors in the shielded cable and is configured to receive the power supply from the power supply system through the inner conductors in the shielded cable, and the secondary circuit collaborates with the primary circuit to convert the power supply, and outputs the working power supply;
• the shield layer located on the RRU side of the shielded cable and the shield layer located on the power supply system side of the shielded cable are grounded respectively;
• a surge over-voltage withstand capability between the primary circuit and the earth is not less than a lightning over-voltage;
• a surge over-voltage withstand capability between each inner conductor in the shielded cable and the shield layer of the shielded cable is not less than the lightning over-voltage;
• and
• the lightning over-voltage derives from a product of a shield layer lightning current that flows through the shield layer of the shielded cable and a resistance of the shield layer of the shielded cable, and the shield layer lightning current is determined according to a lightning current compliant with a specific lightning protection level.

A distributed base station, comprising:

• a radio remote unit (RRU), wherein the RRU comprises an isolation power supply and a working circuit, wherein the isolation power supply is configured to receive a power supply from a power supply system and convert the power supply into a working power supply available to the working circuit,
• a shielded cable comprising inner conductors and a shield layer,
• a power supply system, and
• a base band unit (BBU), wherein the BBU is connected to the RRU through a fiber to process a base band signal,
• the isolation power supply comprises a primary circuit and a secondary circuit, the primary circuit is connected to the inner conductors in the shielded cable and is configured to receive the power supply from the power supply system through the inner conductors in the shielded cable, and the secondary circuit collaborates with the primary circuit to convert the power supply, and outputs the working power supply;
• the shield layer located on the RRU side of the shielded cable and the shield layer located on the power supply system side of the shielded cable are grounded respectively;
• a surge over-voltage withstand capability between the primary circuit and the earth is not less than a lightning over-voltage;
• a surge over-voltage withstand capability between each inner conductor in the shielded cable and the shield layer of the shielded cable is not less than the lightning over-voltage;
• and
• the lightning over-voltage derives from a product of a shield layer lightning current that flows through the shield layer of the shielded cable and a resistance of the shield layer of the shielded cable, and the shield layer lightning current is determined according to a lightning current compliant with a specific lightning protection level.

A distributed base station lightning protection method, comprising:

• using inner conductors in a shielded cable to receive a power supply rectified and output by a power supply system, and converting the power supply into a working power supply for a working circuit in an RRU through collaboration between a secondary circuit and a primary circuit;
• setting a surge over-voltage withstand capability between the primary circuit and the earth to a value that is not less than a lightning over-voltage;
• grounding the shield layer located on the RRU side of the shielded cable and the shield layer located on the power supply system side of the shielded cable respectively;
• and
• setting a surge over-voltage withstand capability between each inner conductor in the shielded cable and the shield layer of the shielded cable to a value that is not less than the lightning over-voltage, wherein the lightning over-voltage derives from a product of a shield layer lightning current that flows through the shield layer of the shielded cable and a resistance of the shield layer of the shielded cable, and the shield layer lightning current is determined according to a lightning current compliant with a specific lightning protection level.

A lightning protection radio remote unit (RRU), comprising:

• a primary circuit configured to receive a power supply from a power supply system through inner conductors in a shielded cable, the shielded cable comprising a shield layer;
• a secondary circuit coupled to the primary circuit, wherein the secondary circuit collaborates with the primary circuit to convert the power supply received by the primary circuit into a working power supply;
• and
• a working circuit coupled to the secondary circuit;
• wherein the secondary circuit outputs the working power supply to power the working circuit, and
• wherein a surge over-voltage withstand capability between the primary circuit and the earth is not less than a lightning over-voltage.