METHOD FOR RELAY PROTECTION OF A SYNCHRONOUS ELECTRICAL MACHINE Russian patent published in 2019 - IPC H02H7/06 

FIELD: electrical equipment; electric power engineering.

SUBSTANCE: according to the method of relay protection of synchronous electric machine stator currents, rotor current, phase voltages at stator outputs and neutral voltage are observed. Phase algorithmic models of all three phases of undamaged electrical machine are used, non-zero phase voltages are determined as the difference between phase voltages and neutral voltage, stator currents and non-zero phase voltages are converted in algorithmic models to signals predicting real values of intact electric machine. At that, phase algorithmic models and corresponding non-zero phase voltages are divided into the first and second ones, two-stage transformations of the observed currents and the first non-zero voltages are performed in two-coordinate measurements. At the first stage, said values are converted in the first algorithmic models to the predicted rotor turn angle, at the second stage the observed currents are again converted, but this time in the second algorithmic models and together with the predicted angle, into the predicted second voltages. Each of the predicted voltages is compared with the corresponding observed voltage, two-coordinate measurement is generated from each pair of compared voltages, displayed on the plane, where the mode area of the intact synchronous machine modes is set, and protection is actuated if all two-coordinate measurements are displayed outside the corresponding region.

EFFECT: expansion of the functionality of the method.

3 cl, 8 dwg