FIELD: electricity.
SUBSTANCE: application: in electrical engineering. According to the method (301, 501) voltage (Va, Vb, Vc) is measured for each phase at least at each output terminal and current (Ia, Ib, Ic) is measured for each phase through the above terminal; then determination (302, 305, 306, 502-506) is made whether the synchronous generator is subject to an internal fault of its any phase. The determination includes the following: conversion (302, 502) of the measured phase currents (Ia, Ib, Ic) and the measured phase voltages (Va, Vb, Vc) to symmetric sequence currents (I1, I2, I0) and symmetric sequence voltages (V1, V2, V0) respectively. The method includes additionally the stages at which at least one of the following variables is controlled (305, 505): residual negative-sequence voltage (ΔV2); residual zero-sequence voltage (ΔV0); negative-sequence coupling impedance (Z2C); zero-sequence coupling impedance (Z0C), at that each of the above variables are calculated on the basis of the symmetric sequence components (I1, I2, I0, V2, V0) and at least one specific impedance (Z00, Z22) of the generator; and determination (306, 504, 506) is made whether the synchronous generator is subject to the internal fault of the winding based on the calculation of at least one residual voltage value (ΔV0, ΔV2) or coupling impedance value (Z2C, Z0C).
EFFECT: reliability improvement.
13 cl, 7 dwg
Authors
Dates
2015-09-27—Published
2011-07-04—Filed