Early warning method of turn-to-turn short circuit fault of exciting winding of synchronous motor

Abstract

According to the invention, early fault warning of a turn-to-turn short circuit of an exciting winding of a synchronous motor is realized based on an LSTM. Normalization processing is carried out on collected data after data acquisition; and then an LSTM network is established and a network model is trained, and a fault early warning value is determined to determine whether the exciting winding isnormal or not. According to the method, the LSTM network is trained by using nine physical quantities as independent variables and three physical quantities as output quantities; and data fusion is carried out on three output quantities to realize fault early warning. According to the invention, with full consideration of the physical quantities related to the rotor turn-to-turn short circuit, aphenomenon of inaccurate measurement of a certain physical quantity or inaccurate prediction value caused by interference of a signal is avoided; a defect caused by using a single criterion such as arotor vibration change method and the like is overcome; the early warning can be performed on the early fault of the turn-to-turn short circuit of the exciting winding can be performed; a fault can bedetected while the load fluctuation of the synchronous motor is large; and no additional measuring device needs to be added in the synchronous motor, so that the method is simple and is easy to implement.

Description

technical field [0001] The invention relates to the technical field of synchronous motors, in particular to the field of diagnosis of inter-turn short-circuit faults of excitation windings of synchronous motors. Background technique [0002] The normal operation of a synchronous motor is an important factor to maintain the stability of the power grid, and the inter-turn short circuit of the field winding is the most common fault in a synchronous motor. The main reasons for the inter-turn short circuit of the field winding are: when the winding is subjected to the centrifugal force of the rotor rotation, the burrs contained in the winding will pierce the winding insulation; poor ventilation will cause the field winding to overheat and cause thermal deformation; design defects in the overall fastening of the rotor end winding ;Oil mist, particles and other foreign matter enter the interior of the rotor, etc. When the short-circuit fault is mild, it has little impact on the pe...

AI Technical Summary

Problems solved by technology

The ideal application state of the detection coil method is the situation of no-load or three-phase short-circuit of the synchronous motor. At this time, the iron core of the synchronous motor is in an unsaturated state, but in actual operation, the magnetic circuit is in a saturated state when the synchronous motor is running with load, and the rotor leakage field Compared with the armature reaction magnetic field is small, so the detection sensitivity is reduced, this method has certain limitations

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