METHOD FOR PROTECTION AGAINST AC ELECTRONIC MACHINE ROTOR ECCENTRICITY Russian patent published in 2019 - IPC H02K15/16 G01R31/34 

FIELD: electrical engineering.

SUBSTANCE: invention relates to the field of electric engineering and can be used for protection against AC rotor eccentricity of AC electric machines. Separation of harmonic components is carried out with frequencies f_c (ν+ 1/p), f_c (ν-1/p) and f_c, where f_c is frequency of main harmonic of network, p is number of poles of electrical machine, ν takes values of 0, 1, 2, … p. Diagnostic criterion of eccentricity of rotor is calculated by formula , where U_ε is value of diagnostic feature of rotor eccentricity; U_(ν±1/p) is harmonic components with frequencies f_c (ν+ 1/p), f_c (ν-1/p); is the value of main harmonic of network with frequency f_c, n is the number of harmonic components with frequencies f_c (ν+ 1/p) and f_c (ν-1/p); if this value is equal to or exceeds the first threshold value of the diagnostic feature, but it is less than the second threshold value of the diagnostic feature, generating the eccentricity signal of the rotor; if this value is equal to or exceeds the second threshold value of the diagnostic characteristic of the electric machine of alternating current, a signal is generated for disconnection of the electric machine from the network.

EFFECT: technical result consists in improvement of accuracy of determination of electric machine rotor eccentricity in method of protection against eccentricity, based on receipt of signal on presence and value of rotor eccentricity, in form of a continuously measured stator phase current signal of an electrical machine, followed by conversion thereof into a unipolar signal, removing a constant component from the unipolar signal from the unipolar signal, equal to D, where D is a constant value with size from zero to maximum value of unipolar signal, and extraction of harmonic components from the obtained signal.

1 cl, 3 dwg