Granted Patent B2

US 9,531,191 · App. 14/160,913 · Granted Dec 27, 2016

Abstract

Claims (27)

1. An apparatus for power imbalance correction comprising:

a plurality of converters for converting a plurality of DC inputs to a multi-phase AC output and coupling the multi-phase AC output to a multi-phase AC line, wherein the plurality of converters comprises a first converter and at least a second converter separate from the first converter, and wherein the first converter couples output power to a first subset of lines of the mufti-phase AC line and the at least a second converter couples output power to a second subset of lines of the multi-phase AC line, the second subset different from the first subset; and

a controller coupled to the plurality of converters for:

(i) determining whether phases of the multi-phase AC output are balanced, and

(ii) controlling, when all phases of the multi-phase AC output are not balanced, at least one converter of the plurality of converters to balance the multi-phase AC output.

2. The apparatus of claim 1 , wherein to balance the multi-phase AC output further comprises compensating for a power difference among the phases output by the at least one converter.

3. The apparatus of claim 2 , wherein controlling the at least one converter further comprises controlling switches in the at least one converter.

4. The apparatus of claim 1 , wherein to balance the multi-phase AC output further comprises compensating for a voltage difference among the phases output by the at least one converter.

5. The apparatus of claim 1 , wherein phases of the multi-phase AC output are determined as balanced by detecting a difference between the phases output by the plurality of converters on the multi-phase AC line does not exceed a first threshold.

6. The apparatus of claim 5 , wherein the controller triggers a shutdown of the apparatus when the difference between the phases exceeds the first threshold and at least one of the phases is of a power level less than a second threshold.

7. The apparatus of claim 1 , wherein the plurality of converters is a multiple of a number of phases in the multi-phase AC line.

8. The apparatus of claim 1 , wherein to balance the multi-phase AC output, the controller decreases a combined power output to the multi-phase AC line to match a power level of a phase with a lowest power level.

9. The apparatus of claim 8 , wherein matching the power level of the phase with the lowest power level further comprises the plurality of converters outputting AC power at a substantially equal power level.

10. The apparatus of claim 1 , wherein to balance the multi-phase AC output, the controller increases a combined power output to the multi-phase AC line to match a power level of a phase with a higher power level to correct the multi-phase AC output of all phases to be at a substantially equal power level.

11. A method for power imbalance correction in a multiphase system comprising:

converting power from a plurality of DC inputs in a plurality of converters to a multi-phase AC output, and coupling the multi-phase AC output to a multi-phase AC line, wherein the plurality of converters comprises a first converter and at least a second converter separate from the first converter, and wherein the first converter couples output power to a first subset of lines of the multi-phase AC line and the at least a second converter couples output power to a second subset of lines of the multi-phase AC line, the second subset different from the first subset;

determining whether phases of the multi-phase AC output are balanced; and

controlling, when all phases of the multi-phase AC output are not balanced, at least one converter of the plurality of converters to balance the multi-phase AC output.

12. The method of claim 11 , wherein to balance the multi-phase AC output further comprises compensating for a power difference among the phases output by the at least one converter.

13. The method of claim 12 , wherein controlling the at least one converter further comprises controlling switches in the at least one converter.

14. The method of claim 11 , wherein to balance the multi-phase AC output further comprises compensating for a voltage difference among the phases output by the at least one converter.

15. The method of claim 11 , wherein phases of the multi-phase AC output are determined as balanced by detecting a difference between the phases output by the plurality of converters on the multi-phase AC line does not exceed a first threshold.

16. The method of claim 15 , wherein the controller triggers a shutdown of the system when the difference between the phases exceeds the first threshold and at least one of the phases is of a power level less than a second threshold.

17. The method of claim 11 , wherein the plurality of converters is a multiple of a number of phases in the multi-phase AC line.

18. The method of claim 11 , wherein to balance the multi-phase AC output comprises decreasing a combined power output to the multi-phase AC line to match a power level of a phase with a lowest power level.

19. The method of claim 18 , wherein matching the power level of the phase with the lowest power level further comprises the plurality of converters are outputting AC power at a substantially equal power level.

20. The method of claim 19 , wherein to balance the multi-phase AC output comprises increasing a combined power output to the multi-phase AC line to match the power level of a phase with a higher power level to correct the multi-phase AC output of all phases to be at a substantially equal power level.

Assignments (7)