Fast Calculation Model and Theoretical Analysis of Rotor Unbalanced Magnetic Pull for Inter-Turn Short Circuit of Field Windings of Non-Salient Pole Generators

• DOI: 10.3390/en10050732
• Publication Date: 2017-05-23T05:47:33Z
• Authors: Guangtao Zhang; Junyong Wu; Liangliang Hao
• Keywords: Air gap (plumbing)

Inter-turn short circuit of field windings (ISCFW) may cause the current a generator to increase, output reactive power decrease, and unit vibration intensify, seriously affecting its safe stable operation. Full integration mechanical electrical characteristics can improve sensitivity online monitoring, detect early embryonic period fault small turns. This paper studies calculations variations unbalanced magnetic pull (UMP), which excitation source rotor is basis key monitoring. In grid load operation, ISCFW are first calculated with multi-loop method, so as obtain numerical solutions stator currents during fault. Next, air-gap analyzed according actual composition modes motor loops in fault, analytic expressions motive force (MMF) density. The UMP obtained by solving integral Maxwell stress. correctness electric quantity calculation verified experiment, conducted one pair-pole non-salient pole model machine. On this basis, comparing simulation analysis results not only verifies accuracy electromagnetic calculation, but also proves that latter has advantages time consumption high efficiency. Finally, influencing factors variation law means an model. develops base for monitoring information.