Method for measuring inherent frequency of stator core/support system of water turbine generator prototype

Abstract

The invention discloses a method for measuring the inherent frequency of a stator core / support system of a water turbine generator prototype. Through arrangement of an automatic excitation regulator, the terminal voltage of a hydropower unit is kept at a rated value. By setting a given value of the zero load frequency, the method changes the rotational speed of a generator rotor. Thereby the method changes an excitation input of the stator core / support system, i.e. the generator rotor rotation magnetic field force wave rotational speed, and measures a frequency response function of the stator core / support system of the water turbine generator prototype under electromagnetic force excitation of different frequency. According to the frequency response function, a frequency value corresponding to the maximum amplitude can be found, and the frequency value is the inherent frequency of the stator core / support system of the water turbine generator prototype. The method only needs to stop the generator and install a sensor, does not need to apply for heavy maintenance, is simple and convenient in measurement, and thus has a wide application prospect in the field of inherent frequency measurement of stator core / support systems of water turbine generator sets.

Description

technical field [0001] The invention relates to a method for measuring the natural frequency of a hydroelectric generator structure, in particular to a method for measuring the natural frequency of a stator core-frame system of a prototype hydroelectric generator. Background technique [0002] In engineering practice, there are various types and complex structures of hydroelectric generators. Units with different capacities adopt different structures. For example, for large or giant units, the rotor often adopts an oblique arm structure, and the stator adopts an oblique vertical rib structure, while some units have a box-shaped rotor structure and radial radial vertical ribs on the stator frame. . In engineering practice, there is often a problem that the core-stator frame vibration of large-scale hydro-generator sets is relatively large, and the natural frequency of the stator core and the stator core-stator frame needs to be measured. The natural frequency measurement me...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the patent of the present invention is to provide a method for measuring the natural frequency of the stator core-stator frame of a large-scale hydroelectric generator set, which solves the problem of long time-consuming measurement of the natural frequency of the conventional stator core-stator frame and the need to apply for overhaul , layout of measuring points, etc.

Images