Open-circuit fault diagnosis of single converter device for directly-driven wind power system

To overcome the complex calculation and the interference vulnerability of traditional fault-diagnosis methods, this paper presents a fault diagnosis method for open-circuit faults of single converter device of the direct-driven permanent magnet wind power system on the basis of variable features of faulty current. The open-circuit fault of converters will seriously affect the operation of the direct-drive permanent magnet wind power system For improving the reliability of the converter system, this method which takes the current as diagnostic parameters, detects the fault occurrence based on the slope variation of the current Park vector phase, positions the motorside fault according to the range located by the Park´s vector phase of the motor-side average current and determines the grid-side fault position in line with the current polarity of each grid-side phase. Hereafter, simulation models verify the accuracy and the reliability of the proposed scheme, and the robustness against the disturbance such as load mutation, grid voltage drop, etc.