Model And Analysis Of Inter-Turn Short Circuit Fault Of Windings In Doubly-Fed Wind Power Generators

Double fed wind power generators(DFIG) one of the mainstream models of wind power generation.The winding inter-turn short-circuit is one of the common faults of DFIF,it is a threat to the safe and efficient operation of wind power generator.So the study of winding inter-turn short circuit has important significance.Currently, most of the research is limited to the study of DFIG itself, ignoring the effect of the control system or simplify the control system, so the conclusion would be ideal, there may be some errors.Some study take into account the influence of the control system, but for the establishment of mathematical model of DFIG,they use the coordinate transformation theory, the research of DFIG under normal conditions is suitable for the thought of mathematical model established by the coordinate transform, when the interturn short circuit occurs, this model can bring errors.A multi-loop math model is built for winding of DFIG under normal and inter-turn short circuit fault conditions.Then the models of the converters on both sides are built,and control strategies are considered. So the study on the winding inter-turn short circuit are under the environment of the wind power generation system.The simulation of DFIG is carried out,using S-Function in Simulink,and the control system is built by the other built-in Simulink modules.The whole simulation system is carried out by the cooperation between the two kinds of modules,motor and control system are combined together.Stator and rotor current waves are gotten under normal and winding inter-turn short circuit conditions and further analysis is done,using FFT analysis.The variation of current under winding inter-turn short circuit is summarize, and some conclusions are gotten.The simulation results are consistent with the experiment situation, the simulation of multi-loop mathematical model based on S function is feasible and the simulation results provide theoretical support for the early detection of winding faults.