초록

A method of detecting a parallel source condition includes calculating a reactive power, comparing the reactive power to a predetermined threshold, and determining a parallel source condition in response to the reactive power exceeding the predetermined threshold.

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1. A method of detecting a parallel source condition comprising: calculating a reactive power for each of a plurality of phases of electric current;calculating a combined average of the reactive power values of the plurality of phases of electric current;comparing the combined average reactive power

1. A method of detecting a parallel source condition comprising: calculating a reactive power for each of a plurality of phases of electric current;calculating a combined average of the reactive power values of the plurality of phases of electric current;comparing the combined average reactive power to a predetermined threshold;determining a parallel source condition in response to the combined average reactive power exceeding the predetermined threshold; andwherein said comparing and determining steps are performed by a controller. 2. The method of claim 1, wherein said step of calculating a reactive power for each of a plurality of phases of electric current comprises: calculating a first reactive power for a first phase of electric current;calculating a second reactive power for a second phase of electric current; andcalculating a third reactive power for a third phase of electric current. 3. The method of claim 1, further comprising: filtering the combined average reactive power. 4. The method of claim 3, wherein said step of filtering the reactive power comprises: applying a first filter to the combined average reactive power to determine a first filtered reactive power; andapplying a second filter to the first filtered reactive power to determine a second filtered reactive power, wherein the first filter and the second filter are first order filters. 5. The method of claim 3, wherein said step of filtering the reactive power comprises: applying a second order filter to the combined average reactive power to determine a filtered reactive power. 6. The method of claim 3, wherein said step of filtering the reactive power is performed by the controller. 7. The method of claim 1, further comprising: actuating at least one contactor to terminate the parallel source condition in response to determining a parallel source condition. 8. The method of claim 1, wherein the predetermined threshold is a negative threshold. 9. The method of claim 8, wherein the predetermined threshold is −50 kVAR. 10. The method of claim 1, wherein said step of calculating a reactive power includes sensing an output current and an output voltage of a generator. 11. The method of claim 1, wherein said steps of calculating a reactive power for each of a plurality of phases of electric current, and calculating a combined average of the reactive power values of the plurality of phases of electric current are performed by the controller. 12. The method of claim 1, wherein the predetermined threshold is constant. 13. The method of claim 1, wherein, in the parallel source condition, two generators are connected in parallel. 14. The method of claim 13, wherein the parallel source condition is caused by a contactor erroneously closing. 15. A parallel source condition detection system comprising: a first generator coupled to a load;a second generator coupled to the load;a controller operable to determine a reactive power associated with at least the first generator and the second generator, to calculate a combined average of the reactive power values, to compare the combined average reactive power to a predetermined threshold, and to determine a parallel source condition in response to the combined average reactive power exceeding the predetermined threshold. 16. The system of claim 15, wherein the load is associated with a vehicle. 17. The system of claim 15, wherein the controller is also operable to filter the reactive power. 18. The system of claim 15, wherein the controller is operable to calculate a first reactive power for a first phase of electric current, calculate a second reactive power for a second phase of electric current, calculate a third reactive power for a third phase of electric current, and calculate a three phase average of the first, second, and third reactive power values. 19. The system of claim 15, wherein the controller includes a digital signal processor. 20. The system of claim 15, wherein the first generator and the second generator are not connected in parallel. 21. A method of detecting a parallel source condition comprising: configuring at least two generators to power at least one load; calculating a reactive power for each of the two generators; and determining that the two generators are connected in parallel, in response to the reactive power for a first of the generators being positive over a period of time and the reactive power of a second of the generators being negative over the same period of time. 22. The method of claim 21, wherein the at least two generator generators are typically not connected in parallel. 23. The method of claim 21, wherein said step of calculating a reactive power for each of the two generators includes: (A) calculating a reactive power for each of a plurality of phases of current of one of the generators;(B) calculating a multi-phase average of the reactive power values that includes the reactive power values for each of the plurality of phases of current; and(C) repeating steps (A)-(B) for the other of the two generators.