Method and system for analyzing influence of joints on shaft voltage of power generator

Abstract

The invention discloses a method and system for analyzing the influence of joints on the shaft voltage of a power generator. The method includes the following steps that a power generator model with non-split-joint laminated pieces of a stator core is established; material attributes of all the parts are set; a plane coordinate system is established for each rotor magnetic pole; the power generator model is evenly divided into two parts, the two parts of the power generator model are moved relative to each other for a preset distance, Boolean calculation is performed on the joint on one side so that the joint can be expanded to a second preset distance, and thus uneven joints are formed in the positions with the difference of 180 degrees; the power generator model with the joints is subjected to adaptive mesh generation; simulation is performed through the model, and the relation between the joints and the shaft voltage of the power generator is analyzed. Through the method and system, the influence of the joints of the laminated pieces of the stator core on the distribution of the magnetic flux of a motor can be analyzed, distribution changes of the magnetic field caused by uneven joints of the laminated pieces of the motor can be dynamically analyzed easily, and thus the shaft voltage is inducted on a rotary shaft, and the accuracy degree of analyzing and researching the shaft voltage is improved.

Description

technical field [0001] The invention relates to generators, in particular to a method and system for analyzing the influence of joints on generator shaft voltage. Background technique [0002] With the wide application of the self-excited thyristor excitation system, a rather large high-frequency shaft voltage source is added to the turbogenerator, and the analysis and protection of the shaft voltage problem become more complicated. Existing analysis methods include: using Kirchhoff’s law of the magnetic circuit for analysis; or, combining the influence of the ratio of the number of lamination seams to the number of pole pairs of the motor on the shaft voltage, using the formula 2k / p for analysis: when 2k / p (k represents the number of stator core disc joints, P represents the number of magnetic poles) After reduction and differentiation, if the numerator is odd, axial voltage will be generated, and if the numerator is even, axial voltage will not be generated. This rule has ...

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Problems solved by technology

[0003] However, due to related problems in the process of installation and operation, the seam gaps of the motor laminations cannot be exactly the same, and the unevenness of the lamination seams is prone to occur, resulting in the asymmetry of the magnetic circuit reluctance and the change of the magnetic field distribution. As the rotor rotates, this magnetic field distribution presents a periodic alternation, which repeats once every revolution of the rotor, and the periodic alternation of the magnetic field distribution further induces shaft voltage on the shaft, so the lamination seam, the magnetic field, and the shaft voltage are three There is an inseparable link between

[0004] However, the existing technology cannot dynamically and accurately analyze the influence of uneven seams on the shaft voltage

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