Operational analysis of D-PMSG based wind power generation system under open-circuit converter faults

The failure rate of converters is higher than any other components in the directly-driven permanent magnet synchronous generator (D-PMSG) based wind power generation systems. Contraposing the changes of the system operating characteristics after converter fault, this paper presents a in-depth study on the operating conditions of converter after an open-circuit fault based on the mathematical model of converters. The studies show that the system is still sustainable after an open-circuit fault of a switch tube, but the operation condition of the converter will be affected and the current waves of the corresponding side will distort. The model of D-PMSG based wind power generation system is developed using MATLAB/Simulink, and the experiment platform for the D-PMSG based wind power generation is given as well. Simulations and experiments are performed under three different types of open-circuit faults. The effects of faults on the system operation characteristics are investigated by the calculation and analysis of some key parameters, such as generator-side current, grid-side current, DC bus voltage, active power output ratio, and total harmonic distortion. The simulation and experimental results show that an open-circuit fault in one converter has little effects on the normal operation of the converter at the other side, but waves of the phase-currents at the corresponding side of fault components will distort. © 2014 State Grid Electric Power Research Institute Press