CN-114838844-B - Method and system for on-line monitoring and judging electric brush faults of generator

CN114838844BCN 114838844 BCN114838844 BCN 114838844BCN-114838844-B

Abstract

The present disclosure provides a method and system for on-line monitoring and judging of generator brush faults, the method comprising obtaining individual temperatures of each brush of a generator; dividing each electric brush into a plurality of areas according to the distribution characteristics of the electric brushes of the generator, calculating the area temperature of each area based on the individual temperature of each electric brush in each area, calculating the overall temperature of all areas based on the individual temperatures of all electric brushes, judging whether obvious differences exist among the plurality of area temperatures, judging that the generator generates centrifugal oscillation if the obvious differences exist, comparing whether the plurality of area temperatures are larger than the overall temperature respectively if the obvious differences do not exist, judging that the electric brush current distribution is abnormal if the area temperatures are larger than the overall temperature, and determining whether each electric brush has faults based on the individual temperature, the overall temperature and the temperature threshold value of each electric brush if the area temperatures are not larger than the overall temperature. According to the method disclosed by the invention, the reliability of monitoring the running state of the electric brush can be improved.

Inventors

YAN YUNFEI
YANG PEIHAO
ZHAO JUNBO
LI ZHIPENG
SUN MENGYAO
GUO XINYU
ZHANG LISONG
CHEN YULUN
SUN GANGHU
WU PENGYUE
CHAI QI
WANG XIAOHUI
KOU SHUICHAO
GAO FENG
XUE LEI
HE TING

Assignees

西安热工研究院有限公司

Dates

Publication Date: 20260508
Application Date: 20220425

Claims (5)

1. The method for monitoring and judging the electric brush faults of the generator on line is characterized by comprising the following steps: acquiring individual temperatures of each electric brush of the generator; Dividing each electric brush into a plurality of areas according to the distribution characteristics of the electric brushes of the generator, calculating the area temperature of each area based on the individual temperature of each electric brush in each area, and calculating the overall temperature of all areas based on the individual temperatures of all electric brushes; dividing each electric brush into a plurality of areas according to the distribution characteristics of the electric brushes of the generator, wherein the distribution characteristics of the electric brushes of the generator are utilized to equally divide the distribution positions of all the electric brushes into a circular area concentric with a large shaft of the generator, and then the circular area is equally divided into 4 areas, wherein each area contains the same number of electric brushes; judging whether obvious differences exist among the temperatures of the areas, and if so, judging that the generator generates centrifugal oscillation; if no obvious difference exists among the plurality of region temperatures, comparing whether the plurality of region temperatures are larger than the whole temperature or not respectively, and if so, judging that the electric brush current distribution is abnormal; If the individual temperature of each electric brush is not greater than the integral temperature, determining whether each electric brush has faults based on the individual temperature of each electric brush, the integral temperature and a temperature threshold, wherein the method comprises the steps of respectively judging whether the individual temperature of each electric brush is greater than the integral temperature, screening out target electric brushes with the individual temperatures greater than the integral temperature, judging whether the individual temperatures of the target electric brushes are greater than the temperature threshold, and if so, judging that the target electric brushes have faults; The calculating the region temperature of each region based on the individual temperatures of each brush in each region includes: selecting any area, calculating the average value of the individual temperatures of all the brushes in the area, taking the average value as the area temperature of the area, and further obtaining the area temperatures of other areas; the calculating the overall temperature of all areas based on the individual temperatures of all brushes includes: the average value of the individual temperatures of all brushes was calculated and taken as the overall temperature of all areas.
2. The method of claim 1, wherein the absence of a significant difference between the plurality of zone temperatures indicates that the values between the plurality of zone temperatures are equal or substantially equal.
3. An on-line monitoring and judging system for generator brush faults, comprising: The system comprises a plurality of temperature sensors, a data acquisition and storage unit, a data processing analysis center and a monitoring platform; the temperature sensors are used for collecting the individual temperature of each electric brush of the generator; The data acquisition and storage unit and the plurality of temperature sensors are used for transmitting the acquired individual temperatures of the electric brushes to the data processing and analysis center; The data processing analysis center is used for dividing each electric brush into a plurality of areas according to the distribution characteristics of the electric brushes of the generator, calculating the area temperature of each area based on the individual temperature of each electric brush in each area, calculating the overall temperature of all areas based on the individual temperature of all electric brushes, judging whether obvious differences exist among the area temperatures, judging that a centrifugal oscillation fault occurs in the generator if the obvious differences exist, respectively comparing whether the area temperatures are larger than the overall temperature if the obvious differences do not exist, judging that abnormal faults exist in electric brush current distribution, judging whether the faults exist according to the individual temperatures of each electric brush and the overall temperature if the temperatures are not larger than the overall temperature, and judging whether the faults exist according to the individual temperatures of each electric brush and the overall temperature threshold; the monitoring platform is used for displaying faults judged by the data processing analysis center; The calculating the region temperature of each region based on the individual temperatures of each brush in each region includes: selecting any area, calculating the average value of the individual temperatures of all the brushes in the area, taking the average value as the area temperature of the area, and further obtaining the area temperatures of other areas; the calculating the overall temperature of all areas based on the individual temperatures of all brushes includes: the average value of the individual temperatures of all brushes was calculated and taken as the overall temperature of all areas.
4. The system for on-line monitoring and judging a brush failure of a generator according to claim 3, wherein the data processing and analyzing center is configured to, when judging whether there is a significant difference between the temperatures of a plurality of the areas, specifically: judging whether the values of the plurality of region temperatures are equal or approximately equal, if the values of the plurality of region temperatures are equal or approximately equal, no obvious difference exists among the plurality of region temperatures, otherwise, obvious difference exists among the plurality of region temperatures.
5. An electronic device, comprising: At least one processor, and A memory communicatively coupled to the at least one processor, wherein, The memory stores instructions executable by the at least one processor to enable the at least one processor to perform the generator brush fault online monitoring and determination method of any one of claims 1-2.

Description

Method and system for on-line monitoring and judging electric brush faults of generator Technical Field The disclosure relates to the field of generator fault online monitoring, in particular to a generator brush fault online monitoring and judging method and system. Background At present, most domestic synchronous generators adopt a static excitation mode, and current and voltage signals generated by an excitation device are added to a rotor excitation winding. Wherein the brushes play a critical role allowing a good electrical connection between the two parts that are in relative rotation. During the operation of the generator, friction exists between the electric brush and the slip ring all the time. For the brushes, the temperature rise and abrasion are caused to a certain extent, but the safety and stability of the generator can be ensured by periodically replacing the carbon brushes within the allowable range. However, the actual running condition of the generator is complex, and the electric brush is often subjected to temperature abnormality or burnout due to the influence of various factors. The main reasons are that the brush braid is in poor contact with the carbon brush or even is disconnected, so that the current flowing through other brushes is increased, the brushes are seriously heated, the pressure of a constant-pressure spring for fixing the carbon brush is unbalanced, when the pressure is reduced, the contact resistance between the carbon brush and a slip ring is increased, the temperature is increased, the centrifugal vibration of the generator is generated, and the poor contact of the carbon brush and the slip ring is also caused, so that the temperature is abnormal. Therefore, the running state of the carbon brush of the generator is monitored on line, the abnormal state is early warned in time, the phenomenon that the carbon brush is burnt out can be effectively avoided, At present, the monitoring of the running state of the carbon brush of the generator is mainly manual inspection, the efficiency and the reliability are lower, part of power plants adopt measuring instruments to replace manual methods for on-line monitoring, but the collected data information still needs manual judgment and analysis, certain hysteresis exists, and in addition, an on-line monitoring system combining the measuring instruments and an intelligent algorithm exists, but certain deviation exists in data processing analysis and fault type judgment. Disclosure of Invention The disclosure provides a method and a system for monitoring and judging a generator brush fault on line, which mainly aim to realize the on-line monitoring of the brush fault and judge the fault type more accurately. According to an embodiment of the first aspect of the present disclosure, there is provided a method for on-line monitoring and judging of a brush failure of a generator, including: acquiring individual temperatures of each electric brush of the generator; Dividing each electric brush into a plurality of areas according to the distribution characteristics of the electric brushes of the generator, calculating the area temperature of each area based on the individual temperature of each electric brush in each area, and calculating the overall temperature of all areas based on the individual temperatures of all electric brushes; judging whether obvious differences exist among the temperatures of the areas, and if so, judging that the generator generates centrifugal oscillation; if no obvious difference exists among the plurality of region temperatures, comparing whether the plurality of region temperatures are larger than the whole temperature or not respectively, and if so, judging that the electric brush current distribution is abnormal; If not, determining whether each brush has a fault based on the individual temperature of each brush, the overall temperature, and a temperature threshold. In one embodiment of the present disclosure, the absence of a significant difference between the plurality of zone temperatures refers to the equality or approximately equality of values between the plurality of zone temperatures. In one embodiment of the disclosure, determining whether each brush has a fault based on the individual temperature of each brush, the overall temperature and a temperature threshold includes determining whether the individual temperature of each brush is greater than the overall temperature, screening out a target brush having an individual temperature greater than the overall temperature, determining whether the individual temperature of the target brush is greater than a temperature threshold, and if so, determining that the target brush has a fault. In one embodiment of the present disclosure, dividing each brush into a plurality of areas according to the distribution characteristics of the brushes of the generator includes equally dividing the distribution positions of all brushes into a circular area concentri