Influence of stator winding inter-turn short-circuit fault on generator electromagnetic torque characteristics

Based on the field-circuit coupled principle, the finite element mathematics model fully considering generator electromagnetic saturation, pole shape, and slot effect is built in this paper. The electromagnetic torque before and after the short-circuit fault in the synchronous generator stator winding is calculated by the Maxwell's tensor method. The strong fundamental frequency and double fundamental frequency electromagnetic torques are found by analyzing the electromagnetic torque spectrum after the stator short-circuit fault. Furthermore, the change rules of the fundamental frequency and double frequency electromagnetic torques in the transient process and the double frequency electromagnetic torque in the steady state along with the short-circuit fault turns and position are revealed. The results are important for diagnosis and detection of the short-circuit faults within synchronous generator stators. © 2016, The editorial office of Transaction of China Electrotechnical Society. All right reserved.