METHOD OF PROTECTION FROM THE ROTOR ECCENTRICITY OF THE ALTERNATING CURRENT ELECTRIC MACHINE Russian patent published in 2018 - IPC G01R31/34 H02H7/08 

FIELD: electricity.

SUBSTANCE: invention relates to electric power engineering and can be used to protect electric machines from rotor eccentricity. Method of protection against rotor eccentricity of electric machine of alternating current is based on receipt of signal about presence and magnitude of rotor eccentricity of electric machine with its subsequent transformation into unipolar signal, removing from unipolar signal constant component equal to D, where D is constant value from zero to largest value of unipolar signal, and separating harmonic components from resulting signal, and then comparing them with threshold values of harmonic components. As signal about presence and magnitude of eccentricity of rotor of electrical machine, continuously measured stator phase current signal of electrical machine is used, separation of harmonic components is carried out with frequencies 2f_c(n-1/p) and 2f_c(n+1/p), where p is number of pairs of poles of AC machine; f_c – frequency of fundamental harmonic network, n can take values 0, 1, 2, etc. Comparison of harmonic components with harmonic threshold values is carried out in such a way that if value of at least one of harmonic components exceeds first harmonic threshold value, signal is generated about presence of rotor eccentricity, and if value of at least one of them exceeds second threshold value of harmonic, signal is generated to turn off electric machine from network.

EFFECT: technical result is to increase reliability and expand scope of method for protecting against rotor eccentricity of AC electric machine.

1 cl, 3 dwg