Patent ID: 9291152
Filing Date: 2016-03-22
CPC Classification: F03D,F05B,G01R,H02J,H02K,H02P,Y02E

Claim Text:
1. A method of operating a power generation system coupled to a power grid during a grid unbalance event or a grid fault event, the method comprising: determining a power grid voltage; determining a negative sequence grid voltage of the power grid from the power grid voltage; determining, based on a comparison of the negative sequence grid voltage with a reference voltage, a negative sequence reactive injection current for selective injection into the power grid; determining, based on the power grid voltage, a positive sequence reactive injection current for selective injection into the power grid; and selecting, based on whether a sum of the determined positive sequence and negative sequence reactive injection currents exceeds a maximum current limit of a converter of the power generation system, one of first and second predetermined processing sequences to be performed using the positive sequence and negative sequence reactive injection currents as inputs, the first predetermined processing sequence being selected when the sum does not exceed the maximum current limit and the second predetermined processing sequence being selected when the sum exceeds the maximum current limit, wherein each of the first and second predetermined processing sequences operates to alter at least one of the determined positive sequence and negative sequence reactive injection currents.