Investigation of the complex of vibration and external magnetic field parameters in the tasks of diagnostics of synchronous generators of gas piston units

Vibration diagnostics of rotating electric machines is well studied and has become widespread, since vibration indicators directly depend on the electrical and mechanical condition of the machine. However, as a number of studies have shown, the analysis of vibration parameters alone does not always allow for an accurate diagnosis. This is especially true for gas piston units, in which the vibration of the internal combustion engine has a significant effect on the synchronous alternator. The study aims to increase the reliability of the results of vibration diagnostics of piston units in operation with synchronous generators with excitation from stationary magnets. It proposes a complex of diagnostics of gas piston aggregates based on vibration parameters and the external magnetic field of the generator. The study was carried out at a working gas-piston power plant consisting of six units with a single capacity of 2 MW operating parallel to the grid. It employed a portable vibration analyzer “Korsar+” to measure the RMS value of vibration at the control points of internal combustion engines and synchronous generators, to analyze the obtained spectra and to make a preliminary diagnosis of the condition. To clarify the diagnosis, we measured the external magnetic field of synchronous generators using the P3-80 electric and magnetic field strength meter and analyzed the amplitude values of the magnetic field strength and spectral characteristics obtained by fast Fourier transform. The results obtained showed the dependence of the spectral composition of the external magnetic field strength on the presence of defects in the windings of the alternating current generator and made it possible to increase the reliability of diagnosis by unambiguously determining the source of increased vibration.