METHOD FOR ALTERNATING CURRENT MACHINE ROTOR PROTECTION FROM ECCENTRICITY Russian patent published in 2014 - IPC G01R31/34 

FIELD: electricity.

SUBSTANCE: method for alternating current machine rotor protection from eccentricity is based on measurement of parameters of the machine magnet field and generation of a tripping signal. The signal with measured parameters of the alternating current machine magnet field is converted to a single-polarity signal, and harmonic components are extracted from it with frequencies f_n(ν-1/p) and f_n(ν+1/p). When a value of at least one frequency exceeds the first threshold value then a signal is generated about the rotor eccentricity. When a value of at least one frequency exceeds the second threshold value then a signal is generated about tripping of the machine from the network, where ν has the value of 0, 1, 2…; p is a number of poles, f_n - frequency of the main harmonic network. Usage of this method allows timely determination of a critical value of the rotor eccentricity and disconnection of the machine from the network and thus reduction of time and costs for post-fault repair for any such machines with any number of the poles.

EFFECT: expanding functional capabilities and the area of application, increasing sensitivity.

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