Method and apparatus for bidirectional power production in a power module
Method and apparatus for generating power. In one embodiment the method comprises determining a value of a DC parameter pertaining to a DC power source providing DC power to an inverter; comparing the value to a threshold; and operating the inverter to generate positive power or negative power based on a result of comparing the value to the threshold.
1. A method for generating power, comprising:
determining a value of a DC parameter pertaining to a DC power source providing DC power to an inverter;
comparing the value to a pre-determined threshold based on an amount of an output from the DC power source; and
dynamically selecting between operating the inverter to generate positive power or negative power based on a result of comparing the value to the pre-determined threshold.
2. The method of claim 1 , wherein the inverter is operated to generate negative power when the value is less than the pre-determined threshold.
3. The method of claim 2 , wherein the DC parameter is the DC power from the DC power source.
4. The method of claim 2 , wherein the DC parameter is a DC voltage set point for biasing the DC power source.
5. The method of claim 2 , further comprising setting, when the value is less than the pre-determined threshold, a DC voltage set point for the DC power source to a fixed value.
6. The method of claim 5 , wherein setting the DC voltage set point to the fixed value causes the inverter to bias the DC power source to operate below a knee of a current-voltage (I-V) curve for the DC power source.
7. The method of claim 2 , wherein the negative power powers a housekeeping supply of the inverter for performing at least one housekeeping function.
8. The method of claim 2 , wherein the inverter is operated during nighttime to generate the negative power and further provides Volt-Ampere reactive (VAr) power while being powered from an AC grid, the AC grid coupled to an AC output of the inverter, and having DC power supplied on a DC side of the inverter.
9. An apparatus for generating power, comprising:
an inverter for (i) determining a value of a DC parameter pertaining to a DC power source providing DC power to the inverter, (ii) comparing the value to a pre-determined threshold based on an amount of an output from the DC power source, and (iii) dynamically selecting between generating positive power or negative power based on a result of comparing the value to the pre-determined threshold.
10. The apparatus of claim 9 , wherein the inverter generates negative power when the value is less than the pre-determined threshold.
11. The apparatus of claim 10 , wherein the DC parameter is the DC power from the DC power source.
12. The apparatus of claim 10 , wherein the DC parameter is a DC voltage set point for biasing the DC power source.
13. The apparatus of claim 10 , wherein the inverter sets, when the value is less than the pre-determined threshold, a DC voltage set point for the DC power source to a fixed value.
14. The apparatus of claim 13 , wherein setting the DC voltage set point to the fixed value causes the inverter to bias the DC power source to operate below a knee of a current-voltage (I-V) curve for the DC power source.
15. The apparatus of claim 10 , wherein the negative power powers a housekeeping supply of the inverter for performing at least one housekeeping function.
16. The apparatus of claim 10 , wherein the inverter generates the negative power during nighttime and further provides Volt-Ampere reactive (VAr) power while being powered from an AC grid, the AC grid coupled to an AC output of the inverter, and having DC power supplied on a DC side of the inverter.
17. A system for generating power, comprising:
a plurality of photovoltaic (PV) modules; and
a plurality of inverters coupled to the plurality of PV modules in a one-to-one correspondence, wherein each inverter of the plurality of inverters (i) determines a value of a DC parameter pertaining to a corresponding PV module, (ii) compares the value to a pre-determined threshold based on an amount of an output from the corresponding PV module, and (iii) dynamically selects between generating positive power or negative power based on a result of comparing the value to the pre-determined threshold.
18. The system of claim 17 , wherein each inverter of the plurality of inverters generates negative power when the value it compares to the pre-determined threshold is less than the pre-determined threshold.
19. The system of claim 18 , wherein the DC parameter is DC power from the corresponding PV module.
20. The system of claim 18 , wherein the DC parameter is a DC voltage set point for biasing the corresponding PV module.