Modeling And Detecting Methods Research Of Stator Winding Turn Fauits In Induction Machines

This paper was supported by the National Natural Science Foundation of China-(The Project of High-Speed Rail United Fund)’Safety prediction and control of high-speed railway electric traction system’(No.U1134205). Induction motors in traction drive system of CRH3EMU had been chosen as the research object. Moreover, the mathematical modeling and fault detecting methods were studied and analyzed in detail when induction motors had short-circuit faults, which can provide theoretical and design basis for the modeling and detecting of Induction motors with stator short-turn faults. Details as follows.Firstly, the physical model of induction motors with stator winding turn faults was analyzed in this paper. The mathematical model in the three-phase stationary coordinate system was established and derived in detail by taking full account of magnetic coupling between the short circuits. On this basis, a simplified fault model in two-phase stationary coordinate system was get by the coordinate transformation, which launched the state equations of induction motors in fault and write the corresponding program.Secondly, a detecting method which chose the Park’s vector of the three-phase stator currents as the fault feature was introduced. In Park’s Vector Approach, the faulty and severity were determined through the observation of the vector circle trajectory by transforming the motor currents from a three-phase stationary coordinate system to a two-phase stationary coordinate system. In Extended Park’s Vector Approach, the faulty and severity were determined through the ratio of the amplitude of the twice fundamental frequency component and the DC component by analyzing its Park’s vector mode spectrum. Furthermore, a detecting method which chose the three-phase stator negative sequence currents as the fault feature was also introduced, in which the faulty and severity can be determined through the amplitude of the negative sequence currents by separating positive sequence and negative sequence components of the stator currents with Hilbert transformation.Thirdly, the algorithms of space vector pulse width modulation theory and vector control theory were introduced in both open-loop and closed-loop control. Simulations were performed based in the MATLAB/SIMULINK simulation platform for the mathematical model and fault detection methods of the induction motors with stator winding turn faults.Finally, experiments were performed based in the RT-LAB and TMS320F2812semi-kind platform for the mathematical model and fault detection methods of the induction motors with stator winding turn faults in both open-loop and closed-loop control, which verified the correctness and effectiveness of the modeling and detecting algorithms proposed in this paper further.