Lightning protection apparatus and photovoltaic power generation system

1. A lightning protection apparatus disposed in a photovoltaic power generation system, wherein the lightning protection apparatus comprises:

a plurality of phase lines located at a to-be-protected location in the photovoltaic power generation system;

a plurality of first lightning protection units in a one-to-one correspondence with the phase lines, wherein each first lightning protection unit comprises:

a first terminal coupled to a corresponding phase line;

a second terminal; and

a second branch comprising a plurality of second gas discharge tubes connected in series between the first terminal and the second terminal; and

a second lightning protection unit connected in series with the first lightning protection units and comprising:

a third terminal coupled to the second terminal;

a fourth terminal coupled to an earth wire; and

at least one gas discharge tube coupled between the earth wire and the first lightning protection units.

2. The lightning protection apparatus of claim 1 , wherein each first lightning protection unit comprises a first varistor.

3. The lightning protection apparatus of claim 1 , wherein each first lightning protection unit further comprises a first branch, and wherein the first branch comprises a plurality of second varistors connected in series between the first terminal and the second terminal.

4. The lightning protection apparatus of claim 1 , wherein each first lightning protection unit further comprises a first gas discharge tube.

5. The lightning protection apparatus of claim 1 , wherein the second lightning protection unit further comprises a third gas discharge tube.

6. The lightning protection apparatus of claim 1 , wherein the second lightning protection unit further comprises a third branch, and wherein the third branch comprises a plurality of fourth gas discharge tubes connected in series between the third terminal and the fourth terminal.

7. The lightning protection apparatus of claim 5 , wherein the second lightning protection unit further comprises a third varistor connected between the third gas discharge tube and the earth wire.

8. The lightning protection apparatus of claim 1 , further comprising a third lightning protection unit connected in parallel to the second lightning protection unit when the phase lines transmit a direct current.

9. The lightning protection apparatus of claim 5 , wherein the second lightning protection unit further comprises a first resistor connected in parallel to the third gas discharge tube.

10. A photovoltaic power generation system, comprising:

a first lightning protection apparatus comprising:

a plurality of phase lines located at a to-be-protected location in the photovoltaic power generation system;

a plurality of first lightning protection units in a one-to-one correspondence with the phase lines, wherein each first lightning protection unit comprises:

a first terminal coupled to a corresponding phase line; and

a second terminal; and

a second lightning protection unit connected in series with the first lightning protection units and comprising:

a third terminal coupled to the second terminal;

a fourth terminal coupled to an earth wire; and

at least one gas discharge tube coupled between the fourth terminal and the first lightning protection units;

a plurality of photovoltaic components comprising output terminals;

a direct current to direct current (DC/DC) converter comprising:

a DC/DC input terminal coupled to the output terminals; and

a DC/DC output terminal;

a direct current to alternating current (DC/AC) converter comprising:

a DC/AC input terminal coupled to a first the DC/DC output terminal; and

a DC/AC output terminal coupled to the first lightning protection apparatus; and

a third lightning protection apparatus connected to the DC/DC output terminal.

11. The photovoltaic power generation system of claim 10 , further comprising a plurality of second lightning protection apparatuses in a one-to-one correspondence with the photovoltaic components, wherein each second lightning protection apparatus is connected to a third output terminal of a corresponding photovoltaic component.

12. The photovoltaic power generation system of claim 10 , wherein each first lightning protection unit further comprises a first varistor.

13. The photovoltaic power generation system of claim 10 , wherein each first lightning protection unit further comprises a first gas discharge tube.

14. The photovoltaic power generation system of claim 10 , wherein the second lightning protection unit further comprises a second gas discharge tube.

15. The photovoltaic power generation system of claim 14 , wherein the second lightning protection unit further comprises a second varistor connected between the second gas discharge tube and the earth wire.

16. The photovoltaic power generation system of claim 14 , wherein the second lightning protection unit further comprises a first resistor connected in parallel to the second gas discharge tube.

17. The photovoltaic power generation system of claim 10 , wherein the first third lightning protection apparatus comprises:

a plurality of third lightning protection units in a one-to-one correspondence with the phase lines of the DC/DC output terminal, wherein each third lightning protection unit comprises:

a fifth terminal coupled to a corresponding phase line; and

a sixth terminal; and

a fourth lightning protection unit connected in series with the third lightning protection units and comprising:

a seventh terminal coupled to the sixth terminal;

an eighth terminal coupled to the earth wire; and

at least one gas discharge tube coupled between the eighth terminal and the third lightning protection units; and

a fifth lightning protection unit connected in parallel to the fourth lightning protection unit.

18. The photovoltaic power generation system of claim 17 , wherein the fifth lightning protection unit comprises a third gas discharge tube.

19. A lightning protection apparatus disposed in a photovoltaic power generation system, wherein the lightning protection apparatus comprises:

a plurality of phase lines located at a to-be-protected location in the photovoltaic power generation system;

a plurality of first lightning protection units in a one-to-one correspondence with the phase lines, wherein each first lightning protection unit comprises:

a first terminal coupled to a corresponding phase line; and

a second terminal;

a second lightning protection unit connected in series with the first lightning protection units and comprising:

a third terminal coupled to the second terminal;

a fourth terminal coupled to an earth wire; and

at least one gas discharge tube coupled between the earth wire and the first lightning protection units; and

a third lightning protection unit connected in parallel to the second lightning protection unit when the phase lines transmit a direct current.

20. The lightning protection apparatus of claim 19 , wherein each first lightning protection unit comprises a first varistor or a first gas discharge tube.