Generator stator end winding degradation diagnosis method based on correlation analysis of electrical quantities and mechanical quantities

Abstract

The invention relates to operation safety monitoring for a generator stator winding of a large steam turbine generator, and discloses a method to diagnose degradation of an end portion of the generator stator winding in an on-line mode based on synchronous measurement and correlation analysis of electrical quantities and mechanical quantities. The method is high in sensitivity and reliability. According to the method, based on a high sampling rate, vibration quantities of an excitation side and a steam turbine side of the end portion of the generator stator three-phase winding are measured, meanwhile three-phase currents of the generator stator winding are measured, by means of break variable of the stator three-phase currents, failure of a power system and electric impact in operation are identified, the electromechanical characteristic component of the stator winding is calculated and recorded, and sample data obtained when winding amplitudes change along with winding currents are accumulated. By means of comparison between actually measured vibration data and vibration data of equivalent currents in history sample records, and the degradation of the end portion of the generator stator winding is identified. The method can automatically adapt to changes of the generator stator winding currents, diagnoses the degradation of the end portion of the stator winding by means of electric impact of the power system, and has good sensitivity.

Description

technical field [0001] The invention relates to on-line diagnosis of deterioration of generator stator end windings of a large steam turbine generator set, and belongs to the field of on-line monitoring, fault diagnosis and condition maintenance of generator sets, and the field of intelligent monitoring and management of main equipment of a power plant. Background technique [0002] Large generator sets are the most critical and important equipment in the power system, and are extremely important to the safety of the power system. The faults of generator sets include mechanical faults and electrical faults. Electrical faults not only cause damage to generators, but may also threaten the stability of the regional power grid and cause blackouts; mechanical faults may lead to the destruction of generator sets and even power plants, causing major Loss of personnel, equipment and environment. [0003] Large generator sets are typical rotating electromechanical equipment. Vibrat...

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Problems solved by technology

[0007] At present, the diagnosis technology for the deterioration of the stator end winding of the generator only refers to the vibration amplitude of the end, and the vibration of the stator winding end is related to the current of the stator winding of the generator. The vibration of the generator under different working conditions is not comparable, so the existing The vibration monitoring method is too simple and not practical

On the other hand, usually in the steady state operation of the generator, the vibration difference at the end of the stator winding is not large, only the transient fault current flowing in the generator can cause serious vibration of the stator winding, and the sampling rate of the existing vibration monitoring system Very low, unable to capture the stator winding end vibration under electrical faults and disturbance impacts, so the sensitivity and reliability of end winding deterioration identification are not satisfactory

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