Solar power generation system
There is provided a solar power generation system including a solar cell, an inverter converting a direct current power generated by the solar cell into an alternating current power, a system voltage measurement unit measuring a system voltage, a voltage drop detector detecting a voltage drop of a power system, based on the system voltage, a first direct current voltage controller controlling a direct current voltage of the inverter to enhance a power generation efficiency of the solar cell, when the voltage drop is not detected, and a second direct current voltage controller controlling the direct current voltage of the inverter to suppress a current output from the inverter, when the voltage drop is detected.
1. A solar power generation system that interconnects with an alternating current power system, the solar power generation system comprising:
a solar cell;
an inverter configured to convert a direct current power generated by the solar cell into an alternating current power;
a system voltage measurement unit configured to measure a system voltage of the alternating current power system;
a voltage drop detector configured to detect a voltage drop of the alternating current power system, based on the system voltage measured by the system voltage measurement unit;
a first direct current voltage controller configured to control a direct current voltage of the inverter such that the power generated by the solar cell is at a maximum power point, when the voltage drop is not detected by the voltage drop detector; and
a second direct current voltage controller configured to control the direct current voltage of the inverter such that a ripple of a current output from the inverter is less than a setting value of an overcurrent relay provided on an output side of the inverter, when the voltage drop is detected by the voltage drop detector.
2. The solar power generation system according to claim 1 , wherein the second direct current voltage controller is configured to perform control to raise the direct current voltage of the inverter, when the voltage drop is detected by the voltage drop detector.
3. The solar power generation system according to claim 2 , wherein the second direct current voltage controller is configured to change a voltage to raise the direct current voltage of the inverter in accordance with the voltage drop, when the voltage drop is detected by the voltage drop detector.
4. The solar power generation system according to claim 1 , wherein the second direct current voltage controller is configured to perform control to lower the direct current voltage of the inverter, when the voltage drop is detected by the voltage drop detector.
5. The solar power generation system according to claim 4 , wherein the second direct current voltage controller is configured to change a voltage to lower the direct current voltage of the inverter in accordance with the voltage drop, when the voltage drop is detected by the voltage drop detector.
6. A control apparatus for an inverter that controls the inverter to be applied to a solar power generation system interconnecting with an alternating current power system and including a solar cell, the control apparatus comprising:
a system voltage measurement unit configured to measure a system voltage of the alternating current power system;
a voltage drop detector configured to detect a voltage drop of the alternating current power system, based on the system voltage measured by the system voltage measurement unit;
a first direct current voltage controller configured to control a direct current voltage of the inverter such that the power generated by the solar cell is at a maximum power point, when the voltage drop is not detected by the voltage drop detector; and
a second direct current voltage controller configured to control the direct current voltage of the inverter such that a ripple of a current output from the inverter is less than a setting value of an overcurrent relay provided on an output side of the inverter, when the voltage drop is detected by the voltage drop detector.
7. The control apparatus for the inverter according to claim 6 , wherein the second direct current voltage controller is configured to perform control to raise the direct current voltage of the inverter, when the voltage drop is detected by the voltage drop detector.
8. The control apparatus for the inverter according to claim 7 , wherein the second direct current voltage controller is configured to change a voltage to raise the direct current voltage of the inverter in accordance with the voltage drop, when the voltage drop is detected by the voltage drop detector.
9. The control apparatus for the inverter according to claim 6 , wherein the second direct current voltage controller is configured to perform control to lower the direct current voltage of the inverter, when the voltage drop is detected by the voltage drop detector.
10. The control apparatus for the inverter according to claim 9 , wherein the second direct current voltage controller is configured to change a voltage to lower the direct current voltage of the inverter in accordance with the voltage drop, when the voltage drop is detected by the voltage drop detector.
11. A control method for an inverter that controls the inverter to be applied to a solar power generation system interconnecting with an alternating current power system and including a solar cell, the control method comprising:
measuring a system voltage of the alternating current power system;
detecting a voltage drop of the alternating current power system, based on the measured system voltage;
controlling a direct current voltage of the inverter such that the power generated by the solar cell is at a maximum power point, when the voltage drop of the alternating current power system is not detected; and
controlling the direct current voltage of the inverter such that a ripple of a current output from the inverter is less than a setting value of an overcurrent relay provided on an output side of the inverter, when the voltage drop of the alternating current power system is detected.
12. The control method for the inverter according to claim 11 , wherein when the voltage drop of the alternating current power system is detected, control is performed to raise the direct current voltage of the inverter.
13. The control method for the inverter according to claim 12 , wherein when the voltage drop of the alternating current power system is detected, a voltage to raise the direct current voltage of the inverter is changed in accordance with the voltage drop.
14. The control method for the inverter according to claim 11 , wherein when the voltage drop of the alternating current power system is detected, control to lower the direct current voltage of the inverter is performed.
15. The control method for the inverter according to claim 14 , wherein when the voltage drop of the alternating current power system is detected, a voltage to lower the direct current voltage of the inverter is changed in accordance with the voltage drop.