CN112986756A - Nondestructive testing method for determining anti-corona structure of generator stator bar - Google Patents
Nondestructive testing method for determining anti-corona structure of generator stator bar Download PDFInfo
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- CN112986756A CN112986756A CN202110134334.8A CN202110134334A CN112986756A CN 112986756 A CN112986756 A CN 112986756A CN 202110134334 A CN202110134334 A CN 202110134334A CN 112986756 A CN112986756 A CN 112986756A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/12—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing
- G01R31/1227—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N25/00—Investigating or analyzing materials by the use of thermal means
- G01N25/72—Investigating presence of flaws
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Abstract
The invention discloses a nondestructive testing method for determining an anti-corona structure of a generator stator bar. The method is based on an infrared thermal imaging temperature detection technology, and by changing the effective value and frequency of alternating current test voltage of a stator bar of the generator and analyzing an infrared temperature image in a withstand voltage test of the stator bar, the specific anti-corona structure of the end part of the stator bar is determined. The method has the characteristics of clear principle, simple flow, quick analysis and no damage to the wire rod, can accurately obtain the specific anti-corona structure of the stator wire rod under the conditions of not dissecting the stator wire rod and not damaging the anti-corona, and has an important role in effectively analyzing and researching the anti-corona structure of the stator wire rod.
Description
Technical Field
The invention relates to a nondestructive testing method for determining an anti-corona structure of a generator stator bar.
Background
The stator bar is one of core components of a generator, the anti-corona design of the stator bar is difficult in insulation design, and the position and the length of an anti-corona structure play a vital role in the anti-corona performance of the stator bar. In a withstand voltage and electrical aging test, the condition of burning loss of a stator bar corona prevention area caused by poor corona prevention design often occurs, the smooth running of the stator bar test is seriously influenced, and the running safety of a generator stator winding is threatened.
The anti-corona technology of the stator bar is a confidential core technology for manufacturers. In the manufacturing process of the stator bar, after the anti-corona layer at the end part of the bar is coated, a plurality of layers of mica tapes are usually coated outside. After the wire rod is solidified, the end part is coated with some insulating protective paint. Therefore, the end corona prevention structure of the stator bar cannot be determined from the appearance.
In order to obtain a specific anti-corona structure of the stator bar, the end regions of the stator bar are usually dissected layer by layer. The method causes serious damage to the winding bar, so that the winding bar cannot be repaired, subsequent related tests cannot be carried out, and huge loss is caused. Meanwhile, the bar dissection has high requirements on the skill level of an operator, and the situation that the specific anti-corona position cannot be determined can occur after the bar dissection, so that the traditional method for determining the anti-corona structure of the stator bar has many limitations.
According to the principle that loss and temperature distribution of the anti-corona region of the stator bar are different under different voltages and different frequencies, the smaller the resistance value of the anti-corona region is, the lower the power supply frequency is, the smaller the loss of the anti-corona region is. Under the condition of voltage rise and frequency reduction, the loss density distribution of the stator bar corona prevention area moves backwards to the lead wire side. Based on the principle, the specific anti-corona structure of the stator bar can be determined without damage through reasonable design of a test method.
Disclosure of Invention
The invention aims to establish a nondestructive testing method for determining an anti-corona structure of a generator stator bar. The method has the characteristics of clear principle, simple flow, quick analysis and no damage to the wire rod, can accurately obtain the specific anti-corona structure of the wire rod under the conditions of not dissecting the stator wire rod and not damaging the anti-corona, and has an important role in effectively analyzing and researching the anti-corona structure of the stator wire rod.
The technical scheme of the invention is as follows:
1) wrapping a low-resistance area (1) of a slot part of the stator bar by using an aluminum foil with the thickness of 0.1mm, wrapping and tightly wrapping the outer side of the aluminum foil by using a glass ribbon with the width of 25mm in a half lap winding way, and stably placing anti-corona tail ends of two end parts of the stator bar to a lead area (2) on a porcelain bottle (3) in the air at the normal temperature of 15-25 ℃;
2) a soft copper wire (4) is tightly wound for a circle at the outer side of an aluminum foil in the middle of a low-resistance area (1) of a stator bar and is connected with a grounding end (6) of a high-voltage variable-frequency test transformer (5), and a soft copper wire (4) is tightly wound for a circle on a lead (7) at one end of the stator bar and is connected with a high-voltage end (8) of the high-voltage variable-frequency test transformer (5);
3) the effective value of the output sine alternating voltage of the high-voltage variable-frequency test transformer (5) is adjusted to be 2.5UN(UNRated voltage of a stator bar), frequency of 50Hz and withstand voltage for 5min, observing the temperature of an anti-corona area (comprising a middle-resistance anti-corona area (10) and a high-resistance anti-corona area (11)) at one end part of the wire rod by using an infrared thermal imaging device (9), determining the position of the axial temperature mutation of the end part of the wire rod as a middle-low-resistance anti-corona lap joint (12), reducing the voltage to 0V, naturally cooling for 3min after a power supply is disconnected, and marking the specific position of the middle-low-resistance anti-corona lap joint (12) according to an infrared thermal imaging image;
4) under the condition that the temperature of the line bar is consistent with the room temperature, the output positive selection alternating voltage limited value of the high-voltage variable-frequency test transformer (5) is adjusted to be 4UNAfter the frequency is 10Hz and the voltage is resisted for 5min, observing the temperature of an anti-corona area (comprising a middle-resistance anti-corona area (10) and a high-resistance anti-corona area (11)) at one end part of the wire rod by using an infrared thermal imaging device (9), determining the position of axial temperature mutation from a middle-resistance lap joint (12) to a lead side, determining the position as a middle-resistance anti-corona lap joint (13), reducing the voltage to 0V, naturally cooling for 3min after the power supply is cut off, and marking the specific position of the middle-resistance anti-corona lap joint (11) according to an infrared thermal imaging image;
5) according to the observed middle-low-resistance anti-corona lap joint (10) and the middle-high-resistance anti-corona lap joint (11), the initial position of the middle-resistance anti-corona area (10), the length of the middle-resistance anti-corona area and the initial position of the high-resistance anti-corona area (11) can be obtained, and the anti-corona structure of the stator bar is determined.
Technical effects
The invention provides a nondestructive testing method for determining an anti-corona structure of a generator stator bar, which is different from the traditional destructive method for determining the anti-corona structure and has the following technical effects:
a) the test is non-destructive. The infrared thermal imaging technology is adopted, different anti-corona lap joint positions are obtained through the temperature change trend, and the method only carries out short-time pressure-resistant test on the wire rod, so that the wire rod is basically not damaged, irreparable damage to the wire rod caused by the traditional dissection method is avoided, and the subsequent scientific research test of the wire rod is smoothly carried out.
b) The determination of the anti-corona structure is more accurate. In a pressure test, the temperature distribution condition can be effectively analyzed and observed through a shot infrared thermal imaging cloud picture, the anti-corona structure of the winding bar can be accurately obtained, and the accuracy of determining the anti-corona structure by the traditional method depends on the skill level of an operator and has great uncertainty.
c) The time to determine the anti-corona structure is short. Through two alternating voltage withstand voltage tests with different alternating voltage effective values and different frequencies, the main anti-corona structure of the stator bar can be determined within one hour, and compared with the traditional dissection method, the total time for determining the anti-corona structure is shorter.
Drawings
FIG. 1 is a schematic diagram of a nondestructive testing test for determining an anti-corona structure of a stator bar of a generator.
Detailed Description
1) Wrapping a low-resistance area (1) of a slot part of the stator bar by using an aluminum foil with the thickness of 0.1mm, wrapping and tightly wrapping the outer side of the aluminum foil by using a glass ribbon with the width of 25mm in a half lap winding way, and stably placing anti-corona tail ends of two end parts of the stator bar to a lead area (2) on a porcelain bottle (3) in the air at the normal temperature of 15-25 ℃;
2) a soft copper wire (4) is tightly wound for a circle at the outer side of an aluminum foil in the middle of a low-resistance area (1) of a stator bar and is connected with a grounding end (6) of a high-voltage variable-frequency test transformer (5), and a soft copper wire (4) is tightly wound for a circle on a lead (7) at one end of the stator bar and is connected with a high-voltage end (8) of the high-voltage variable-frequency test transformer (5);
3) the effective value of the output sine alternating voltage of the high-voltage variable-frequency test transformer (5) is adjusted to be 2.5UN(UNRated voltage of the stator bar), the frequency is 50Hz, after withstand voltage is 5min, one side end part of the wire bar is observed by using an infrared thermal imaging device (9)The temperature of an anti-corona area (comprising a middle-resistance anti-corona area (10) and a high-resistance anti-corona area (11)) is determined as the position of the axial temperature sudden change of the end part of the wire rod, the position is determined as a middle-low resistance anti-corona lap joint (12), the voltage is reduced to 0V, the temperature is naturally reduced for 3min after the power supply is cut off, and the specific position of the middle-low resistance anti-corona lap joint (12) is marked according to an infrared thermal imaging image;
4) under the condition that the temperature of the line bar is consistent with the room temperature, the output positive selection alternating voltage limited value of the high-voltage variable-frequency test transformer (5) is adjusted to be 4UNAfter the frequency is 10Hz and the voltage is resisted for 5min, observing the temperature of an anti-corona area (comprising a middle-resistance anti-corona area (10) and a high-resistance anti-corona area (11)) at one end part of the wire rod by using an infrared thermal imaging device (9), determining the position of axial temperature mutation from a middle-resistance lap joint (12) to a lead side, determining the position as a middle-resistance anti-corona lap joint (13), reducing the voltage to 0V, naturally cooling for 3min after the power supply is cut off, and marking the specific position of the middle-resistance anti-corona lap joint (11) according to an infrared thermal imaging image;
5) according to the observed middle-low-resistance anti-corona lap joint (10) and the middle-high-resistance anti-corona lap joint (11), the initial position of the middle-resistance anti-corona area (10), the length of the middle-resistance anti-corona area and the initial position of the high-resistance anti-corona area (11) can be obtained, and the anti-corona structure of the stator bar is determined.
Claims (1)
1. The method is characterized in that: the method comprises the following steps:
1) wrapping a low-resistance area (1) of a slot part of the stator bar by using an aluminum foil with the thickness of 0.1mm, wrapping and tightly wrapping the outer side of the aluminum foil by using a glass ribbon with the width of 25mm in a half lap winding way, and stably placing anti-corona tail ends of two end parts of the stator bar to a lead area (2) on a porcelain bottle (3) in the air at the normal temperature of 15-25 ℃;
2) a soft copper wire (4) is tightly wound for a circle at the outer side of an aluminum foil in the middle of a low-resistance area (1) of a stator bar and is connected with a grounding end (6) of a high-voltage variable-frequency test transformer (5), and a soft copper wire (4) is tightly wound for a circle on a lead (7) at one end of the stator bar and is connected with a high-voltage end (8) of the high-voltage variable-frequency test transformer (5);
3) the effective value of the output sine alternating voltage of the high-voltage variable-frequency test transformer (5) is adjusted to be 2.5UN(UNIs a stator barRated voltage) and frequency of 50Hz, after withstand voltage is kept for 5min, observing the temperature of an anti-corona area (comprising a middle-resistance anti-corona area (10) and a high-resistance anti-corona area (11)) at one end part of the line rod by using an infrared thermal imaging device (9), determining the position of the axial temperature mutation of the end part of the line rod as a middle-low resistance anti-corona lap joint (12), reducing the voltage to 0V, naturally cooling for 3min after a power supply is cut off, and marking the specific position of the middle-low resistance anti-corona lap joint (12) according to an infrared thermal imaging image;
4) under the condition that the temperature of the line bar is consistent with the room temperature, the output positive selection alternating voltage limited value of the high-voltage variable-frequency test transformer (5) is adjusted to be 4UNAfter the frequency is 10Hz and the voltage is resisted for 5min, observing the temperature of an anti-corona area (comprising a middle-resistance anti-corona area (10) and a high-resistance anti-corona area (11)) at one end part of the wire rod by using an infrared thermal imaging device (9), determining the position of axial temperature mutation from a middle-resistance lap joint (12) to a lead side, determining the position as a middle-resistance anti-corona lap joint (13), reducing the voltage to 0V, naturally cooling for 3min after the power supply is cut off, and marking the specific position of the middle-resistance anti-corona lap joint (11) according to an infrared thermal imaging image;
5) according to the observed middle-low-resistance anti-corona lap joint (10) and the middle-high-resistance anti-corona lap joint (11), the initial position of the middle-resistance anti-corona area (10), the length of the middle-resistance anti-corona area and the initial position of the high-resistance anti-corona area (11) can be obtained, and the anti-corona structure of the stator bar is determined.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113466642A (en) * | 2021-07-02 | 2021-10-01 | 北京北重汽轮电机有限责任公司 | Localization method of anticorona paint of capacitor voltage-sharing anticorona structure |
Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03246472A (en) * | 1990-02-23 | 1991-11-01 | Matsushita Electric Ind Co Ltd | Winding abnormality detecting device for winding coil for motor |
| CN101345458A (en) * | 2008-05-22 | 2009-01-14 | 山东齐鲁电机制造有限公司 | Full anti-dizzy VPI impregnation stator line stick and its industrial frequency overpressure-resistant detection method |
| EP2333938A1 (en) * | 2009-12-09 | 2011-06-15 | Alstom Technology Ltd | Stator bar |
| CN203479967U (en) * | 2013-07-29 | 2014-03-12 | 哈尔滨电机厂有限责任公司 | Device for observing stator coil and winding voltage withstanding tests of large generator |
| CN104269953A (en) * | 2014-09-24 | 2015-01-07 | 湖南科技大学 | High-voltage motor stator coil corona-preventing structure optimizing method based on electric field analysis |
| US20150236569A1 (en) * | 2014-02-19 | 2015-08-20 | Christopher David Brown | Monitoring the operating conditions of electric generators and motors by partial measurements |
| CN106646159A (en) * | 2016-12-12 | 2017-05-10 | 华北电力科学研究院有限责任公司 | Generator stator end winding corona detection method and device |
| CN207051394U (en) * | 2017-08-15 | 2018-02-27 | 西安交通大学 | A kind of generator stator bar end surface current potential contactless measuring system |
| CN108802560A (en) * | 2018-07-16 | 2018-11-13 | 哈尔滨电机厂有限责任公司 | A kind of electric testing device of large turbo-type generator stator simulation winding |
| CN109696605A (en) * | 2018-10-19 | 2019-04-30 | 中电华创电力技术研究有限公司 | A kind of lifetime estimation method of generator stator bar epoxy resin mica insulation |
| JP2019152635A (en) * | 2018-03-06 | 2019-09-12 | アイチエレック株式会社 | Stator test device and stator test method |
| CN111157895A (en) * | 2020-02-10 | 2020-05-15 | 哈尔滨理工大学 | High-voltage motor stator winding end surface potential measuring system |
| CN211478525U (en) * | 2019-12-22 | 2020-09-11 | 国家电网有限公司 | System for diagnosing insulation defect at end part of stator wire rod of generator |
-
2021
- 2021-01-29 CN CN202110134334.8A patent/CN112986756B/en active Active
Patent Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03246472A (en) * | 1990-02-23 | 1991-11-01 | Matsushita Electric Ind Co Ltd | Winding abnormality detecting device for winding coil for motor |
| CN101345458A (en) * | 2008-05-22 | 2009-01-14 | 山东齐鲁电机制造有限公司 | Full anti-dizzy VPI impregnation stator line stick and its industrial frequency overpressure-resistant detection method |
| EP2333938A1 (en) * | 2009-12-09 | 2011-06-15 | Alstom Technology Ltd | Stator bar |
| CN203479967U (en) * | 2013-07-29 | 2014-03-12 | 哈尔滨电机厂有限责任公司 | Device for observing stator coil and winding voltage withstanding tests of large generator |
| US20150236569A1 (en) * | 2014-02-19 | 2015-08-20 | Christopher David Brown | Monitoring the operating conditions of electric generators and motors by partial measurements |
| CN104269953A (en) * | 2014-09-24 | 2015-01-07 | 湖南科技大学 | High-voltage motor stator coil corona-preventing structure optimizing method based on electric field analysis |
| CN106646159A (en) * | 2016-12-12 | 2017-05-10 | 华北电力科学研究院有限责任公司 | Generator stator end winding corona detection method and device |
| CN207051394U (en) * | 2017-08-15 | 2018-02-27 | 西安交通大学 | A kind of generator stator bar end surface current potential contactless measuring system |
| JP2019152635A (en) * | 2018-03-06 | 2019-09-12 | アイチエレック株式会社 | Stator test device and stator test method |
| CN108802560A (en) * | 2018-07-16 | 2018-11-13 | 哈尔滨电机厂有限责任公司 | A kind of electric testing device of large turbo-type generator stator simulation winding |
| CN109696605A (en) * | 2018-10-19 | 2019-04-30 | 中电华创电力技术研究有限公司 | A kind of lifetime estimation method of generator stator bar epoxy resin mica insulation |
| CN211478525U (en) * | 2019-12-22 | 2020-09-11 | 国家电网有限公司 | System for diagnosing insulation defect at end part of stator wire rod of generator |
| CN111157895A (en) * | 2020-02-10 | 2020-05-15 | 哈尔滨理工大学 | High-voltage motor stator winding end surface potential measuring system |
Non-Patent Citations (2)
| Title |
|---|
| 孙永鑫 等: "定子线棒防晕区温升机理和检测分析方法", 《大电机技术》 * |
| 张社红: "10kV高原电机定子线圈防晕结构设计及性能测试", 《中小型电机》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113466642A (en) * | 2021-07-02 | 2021-10-01 | 北京北重汽轮电机有限责任公司 | Localization method of anticorona paint of capacitor voltage-sharing anticorona structure |
| CN113466642B (en) * | 2021-07-02 | 2023-11-14 | 北京北重汽轮电机有限责任公司 | Method for localization of anti-corona paint with capacitor voltage-equalizing anti-corona structure |
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