CN105759153B - A kind of thermal ageing test device and method under the conditions of analogue transformer winding overload - Google Patents
A kind of thermal ageing test device and method under the conditions of analogue transformer winding overload Download PDFInfo
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- CN105759153B CN105759153B CN201610256144.2A CN201610256144A CN105759153B CN 105759153 B CN105759153 B CN 105759153B CN 201610256144 A CN201610256144 A CN 201610256144A CN 105759153 B CN105759153 B CN 105759153B
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- transformer winding
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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
- G01R31/003—Environmental or reliability tests
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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
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- Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Housings And Mounting Of Transformers (AREA)
- Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
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Abstract
The present invention relates to the thermal ageing test device and methods under the conditions of a kind of analogue transformer winding overload, belong to insulation of electrical installation on-line monitoring and fault diagnosis field.The device includes hermetically sealed can, copper electrode, breather valve, sensor stand, hermetically sealed can is used to ensure the condition of sealing anaerobic that transformer winding is in ageing process, and for conducting electric current and fixed transformer winding, breather valve is used to be passed through nitrogen discharge air copper electrode, sensor stand measures winding temperature and each region oil temperature in tank body for installing sensor.Thermal ageing test device and method under the conditions of analogue transformer winding overload provided by the invention using temperature as target, flows through winding current size and carries out paper oil insulation accelerating thermal aging test by way of reaching target temperature adjusting.So as to analyze transformer paper oil insulation aging rule in an overload condition.
Description
Technical field
The invention belongs to insulation of electrical installation on-line monitoring and fault diagnosis fields, are related to a kind of analogue transformer winding mistake
Thermal ageing test device and method under the conditions of load.
Background technology
The core that power transformer is converted as energy in electric energy transmission and delivery process, the accident that failure causes will be led
The interruption of supply of electric power is caused, and causes huge economic loss.Power transformer overload capability becomes simultaneously as restriction power grid
The main reason for capacitance limit further improves, when the accident situation of N-1 occurs in substation, if transformer has higher mistake
Loading capability, can not only avoid transformer from being damaged because of overload, additionally it is possible to reserve certain time to scheduling, spatial load forecasting is existed
In the range of safety and stability " running limit of paired running main transformer can be effectively improved by improving transformer overload ability, is improved
Main transformer rate of load condensate, significant to the operation of electricity net safety stable ".
Important component of the transformer Oil-Paper Insulation as transformer interior insulation, by the transformer fault of its initiation
Account for major portion.Oilpaper is influenced and gradual aging in During Process of Long-term Operation by factors such as electricity, heat, machinery, moisture and corrosion,
Decreasing insulating simultaneously causes insulation defect occur or even causes the main minor insulation failure of transformer, so as to threaten the peace of transformer
Row for the national games.Its hot(test)-spot temperature significantly improves transformer in an overload condition, the aggravation of insulation ag(e)ing rate, and laboratory is adopted at present
With the aging rule of the technique study transformer Oil-Paper Insulation of accelerated aging test, often one is pressed with winding and insulating oil
The mode that the no temperature difference of stand oil paper ratio heats simultaneously carries out, it is contemplated that transformer oil flash-point problem, heating temperature is usually not
It can exceed that 140 DEG C, it is impossible to the more comprehensively winding temperature rise aging of reaction transformer in an overload condition.
Invention content
In view of this, the purpose of the present invention is to provide the thermal ageing tests under the conditions of a kind of analogue transformer winding overload
Device and method by being measured in order to control with temperature, flows through the predetermined temperature that arrives of heating in winding in closed environment by electric current
Mode carries out paper oil insulation accelerating thermal aging test.
An object of the present invention is to provide the thermal ageing test device under the conditions of a kind of analogue transformer winding overload, leads to
Cross following technical scheme realization：
Thermal ageing test device under the conditions of a kind of analogue transformer winding overload, including hermetically sealed can, copper electrode, ventilation
Valve, sensor stand；Breather valve opening, sensor insert port and copper electrode opening are provided on the lid of the hermetically sealed can, it is described
Breather valve opening is for installing breather valve, and the sensor insert port is for installing sensor stand, on the sensor stand
It is provided with sensor, for the copper electrode opening for setting copper electrode, the junction of copper electrode and hermetically sealed can uses epoxy resin
Fastener is compressed, and the copper electrode conducts electric current and fixed transformer winding for connecting tank body internal and external parts.
Further, the hermetically sealed can include tank body, sealing cover, seal washer and fastening clip, tank body opening surrounding with
The bottom surrounding of sealing cover is provided with baltimore groove, and seal washer is placed in baltimore groove, for ensureing that tank body is closed with sealing cover.
Further, the breather valve is two, the left and right ends of sealed tank cap is separately positioned on, for air in tank body
Carry out emptying process.
Further, the copper electrode is two, and two epoxy resin fasteners are respectively adopted in sealed tank cap in each copper electrode
Positive and negative compressed, then the screw thread of itself is screwed by nut and copper electrode.
Further, the upper and lower end parts difference providing holes of the copper electrode, for across transformer winding, copper electrode up and down
End vertical punches tapping, is connected with hole.
Further, the sensor stand include vertical bar, several horizon bars and external member, the horizon bar by external member with
Vertical bar connects；The vertical bar provides support for horizon bar, adjusts the height of horizon bar；Horizon bar is equipped with trepanning, for pacifying
Fill temperature sensor.
The second object of the present invention is to provide a kind of thermal ageing test method under the conditions of analogue transformer winding overload, lead to
Cross following technical scheme realization：
A kind of thermal ageing test method under the conditions of analogue transformer winding overload, includes the following steps：
Transformer winding is turned to shape to be measured by step 1)；
Processing is dried to transformer oil and transformer winding in step 2)；
Transformer winding copper wire is put into hermetically sealed can by step 3), is connect with the copper electrode being arranged in hermetically sealed can, will be passed
Sensor is placed near transformer winding；Copper electrode conducts electric current and fixed transformer winding for connecting tank body internal and external parts
Step 4) will be poured into through the processed transformer oil of step 2) in tank body, and transformer winding is dipped in oil, adjust peace
Sensor stand position in hermetically sealed can covers the sealing cover of tank body, reinforces, and transformer winding and sensor is made to be in close
Seal ring border；
Step 5) discharges the air in hermetically sealed can；
Step 6) is powered to copper electrode, makes transformer winding self-heating, carries out degradation.
Further, transformer winding is turned to set shape by the step 1) as needed.
Further, the step 5) is discharged the air in hermetically sealed can by inputting nitrogen, is set on the sealing cover of hermetically sealed can
There are two breather valve, for inputting nitrogen, another breather valve is used to discharge air a breather valve.
Further, it is dried in the step 2) and specifically includes following steps：Step 21) exists oil with transformer winding
It is 48 hours dry in 90 DEG C/50Pa environment；Transformer winding is put into oil by step 22), the immersion oil in 40 DEG C/50Pa environment
24 hours.
In order to achieve the above objectives, the present invention provides following technical solution：
The beneficial effects of the present invention are：Heat ageing under the conditions of a kind of analogue transformer winding overload provided by the invention
Experimental provision, the device provides sealings and anaerobic experiment condition, guarantee test method can realize that transformer winding is not surpassing
The degradation simulated in the case of transformer oil flash-point (140 DEG C) under the conditions of winding overload under higher temperature (>=140 DEG C) is crossed,
So as to analyze transformer paper oil insulation aging rule in an overload condition.
Description of the drawings
To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention is made below in conjunction with attached drawing into
The detailed description of one step, wherein：
Fig. 1 is the structure diagram of device of the present invention；
Fig. 2 is the structure chart of sealed shell of tank；
Fig. 3 is the mechanism map of sensor stand；
Wherein, 1 is breather valve, and 2 be sensor insert port, and 3 be epoxy resin fastener, and 4 be copper electrode, and 5 be sensor branch
The vertical bar of frame, 6 be the horizon bar and external member of sensor stand, and 7 be sensor, and 8 be copper electrode trepanning.
Specific embodiment
Below in conjunction with attached drawing, the preferred embodiment of the present invention is described in detail.
The present invention provides the thermal ageing test device under the conditions of a kind of analogue transformer winding overload, which includes providing
The stainless steel hermetically sealed can of ageing environment, copper electrode, breather valve, sensor stand；Breather valve opening is provided on the lid of hermetically sealed can,
Sensor insert port and copper electrode opening.
Hermetically sealed can includes the bottom of tank body, sealing cover, seal washer and fastening clip, tank body opening surrounding and sealing cover
Surrounding is provided with baltimore groove, and seal washer is placed in baltimore groove, for ensureing that tank body is closed with sealing cover, sealing structure is simple,
Sealing effect is good.
For breather valve opening for installing breather valve, breather valve is two, can be two ball valves, be separately positioned on sealing
The left and right ends of cover discharge internal air with nitrogen after the completion of tank body sealing, ensure the anaerobic experiment in ageing process
Condition.
Sensor insert port is equipped with temperature sensor on sensor stand, is ensureing gas for installing sensor stand
Signal is exported on the basis of close property, measures winding and oil temperature temperature in tank in real time.There are two sensor insert ports on sealing cover.
Sensor stand includes vertical bar, several horizon bars and external member, and horizon bar is connect by external member with vertical bar；It can be according to measurement need
Different number of horizontal stand is installed.External member is is threaded with substrate hold-down function copper ring, and horizontal stand is connected with copper ring, copper
Ring is connected as horizon bar with vertical bar and provides support, can also adjust the height of horizon bar；Horizon bar is equipped with trepanning, for pacifying
Fill temperature sensor.During the experiment, it is copper winding technique is close into ageing can is placed on copper electrode fixation after specific shape
It is honored as a queen and carries out energization heating, while the temperature of winding in tank body and each region oil temperature are supervised in real time by internal sensor
Control.
Opening is for setting copper electrode, and the junction of copper electrode and hermetically sealed can is compressed using epoxy resin fastener, copper
For electrode for connecting tank body internal and external parts, conduction electric current and fixed transformer winding, copper electrode is two, each copper electrode difference
It is compressed in the positive and negative of sealed tank cap using two epoxy resin fasteners, is carried out by the screw thread of nut and copper electrode itself
It screws, copper electrode is made to be carried out with sealing cover strong bonded.The upper and lower end parts of copper electrode are respectively arranged with hole, for across transformer
Flat winding, the upper and lower end parts vertical perforating tapping of copper electrode, connects with hole, can be opposite to screw copper winding in square hole into
Row compresses, and ensures that it is combined closely, enhances its mechanical structure stability.
The present invention also provides a kind of thermal ageing test method under the conditions of analogue transformer winding overload, specifically include with
Lower step：
Transformer winding is turned to specific shape by step 1)；
Transformer winding is turned into set shape as needed, can such as turn to three-layer type winding, the head of each layer
Tail, which is connected, ensures that electric current continues through, and same layer winding temperature is identical in ageing process, and different layers temperature is different, therefore can be in reality
Three kinds of different test temperatures are obtained during testing and carry out agings；Therefore three can be obtained in primary experiment during the experiment
Aging under different temperatures.
Processing is dried to transformer oil and transformer insulated winding in step 2).
Drying process specifically includes following steps：Step 21) in 90 DEG C/50Pa environment, does oil and transformer winding
Dry 48 hours；Transformer winding is put into oil by step 22), the immersion oil 24 hours in 40 DEG C/50Pa environment.
Winding copper wire is put into hermetically sealed can by step 3), is connect with the copper electrode being arranged in hermetically sealed can, sensor is pacified
It is placed in winding precalculated position.Copper electrode conducts electric current and fixed transformer winding for connecting tank body internal and external parts.
Step 4) will be poured into through the processed transformer oil of step 2) in tank body, and transformer winding is dipped in oil, adjust peace
Sensor stand position in hermetically sealed can, closes the lid, and reinforces sealing；
Step 5) discharges the air in hermetically sealed can；By inputting the air in high-purity nitrogen discharge hermetically sealed can, sealing
It is set at the top of tank there are two breather valve, for inputting nitrogen, another breather valve is used to discharge air a breather valve.
Step 6) is powered to copper electrode, makes winding self-heating, carries out degradation.Electric current is occurred by high current
Device generates, and flowed by the copper electrode of sealing cover exposed parts makes it be flowed out again by another pole after generating heat using winding, is formed
Circuit.By internal sensor control temperature, ensure that ageing environment temperature is consistent.
Finally illustrate, preferred embodiment above is merely illustrative of the technical solution of the present invention and unrestricted, although logical
It crosses above preferred embodiment the present invention is described in detail, however, those skilled in the art should understand that, can be
Various changes are made to it in form and in details, without departing from claims of the present invention limited range.
Claims (8)
1. a kind of thermal ageing test device under the conditions of analogue transformer winding overload, it is characterised in that：Including hermetically sealed can, copper electricity
Pole, breather valve, sensor stand；Breather valve opening is provided on the lid of the hermetically sealed can, sensor insert port and copper electrode are opened
Mouthful, for installing breather valve, the sensor insert port is used to install sensor stand, the sensor breather valve opening
Sensor fastening device is provided on stent, the copper electrode is open to set copper electrode, the connection of copper electrode and hermetically sealed can
Place is compressed using epoxy resin fastener, and the copper electrode conducts electric current and fixed transformation for connecting tank body internal and external parts
Device winding；The hermetically sealed can includes tank body, sealing cover, seal washer and fastening clip, tank body opening surrounding and sealing cover
Bottom surrounding is provided with baltimore groove, and seal washer is placed in baltimore groove, for ensureing that tank body is closed with sealing cover；The breather valve
It is two, is separately positioned on the left and right ends of sealed tank cap, for carries out emptying process to air in tank body.
2. the thermal ageing test device under the conditions of a kind of analogue transformer winding overload according to claim 1, feature
It is：The copper electrode be two, each copper electrode be respectively adopted two epoxy resin fasteners sealed tank cap positive and negative into
Row compresses, then the screw thread of itself is screwed by nut and copper electrode.
3. the thermal ageing test device under the conditions of a kind of analogue transformer winding overload according to claim 1, feature
It is：The upper and lower end parts of the copper electrode are respectively arranged with hole, for across transformer winding, the upper and lower end parts of copper electrode to be vertical
Tapping is punched, is connected with hole.
4. the thermal ageing test device under the conditions of a kind of analogue transformer winding overload according to claim 1, feature
It is：The sensor stand includes vertical bar, several horizon bars and external member, and the horizon bar is connected by external member and vertical bar
It connects；The vertical bar provides support for horizon bar, adjusts the height of horizon bar；Horizon bar is equipped with trepanning, is passed for installing temperature
Sensor.
5. a kind of thermal ageing test method under the conditions of analogue transformer winding overload, it is characterised in that：Include the following steps：
Transformer winding is turned to shape to be measured by step 1)；
Processing is dried to transformer oil and transformer winding in step 2)；
Transformer winding copper wire is put into hermetically sealed can by step 3), is connect with the copper electrode being arranged in hermetically sealed can, by sensor
It is placed near transformer winding and winding；Copper electrode for connecting tank body internal and external parts, conduction electric current and fixed transformer around
Group；
Step 4) will be poured into through the processed transformer oil of step 2) in tank body, and transformer winding is dipped in oil, and adjusting is mounted on
Sensor stand position in hermetically sealed can covers the sealing cover of tank body, reinforces, transformer winding and sensor is made to be in sealing ring
Border；
Step 5) is discharged the air in hermetically sealed can using nitrogen；
Step 6) is powered to copper electrode, makes transformer winding self-heating, carries out degradation.
6. the thermal ageing test method under the conditions of a kind of analogue transformer winding overload according to claim 5, feature
It is：Transformer winding is turned to set shape by the step 1) as needed.
7. the thermal ageing test method under the conditions of a kind of analogue transformer winding overload according to claim 5, feature
It is：The step 5) is discharged the air in hermetically sealed can by inputting nitrogen, sets that there are two ventilate on the sealing cover of hermetically sealed can
Valve, for inputting nitrogen, another breather valve is used to discharge air a breather valve.
8. the thermal ageing test method under the conditions of a kind of analogue transformer winding overload according to claim 5, feature
It is：It is dried in the step 2) and specifically includes following steps：Step 21) is by oil with transformer winding in 90 DEG C/50Pa
It is 48 hours dry in environment；Transformer winding is put into oil by step 22), the immersion oil 24 hours in 40 DEG C/50Pa environment.
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| CN201610256144.2A CN105759153B (en) | 2016-04-22 | 2016-04-22 | A kind of thermal ageing test device and method under the conditions of analogue transformer winding overload |
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| CN201610256144.2A CN105759153B (en) | 2016-04-22 | 2016-04-22 | A kind of thermal ageing test device and method under the conditions of analogue transformer winding overload |
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| CN105759153B true CN105759153B (en) | 2018-06-15 |
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| CN110462361B (en) * | 2016-12-31 | 2022-05-24 | 日立能源瑞士股份公司 | System and method for monitoring components in a power transformer or the like |
| CN106644557B (en) * | 2017-01-04 | 2023-05-16 | 中国南方电网有限责任公司超高压输电公司检修试验中心 | Testing device for transformer insulating material under same condition aging stage sampling |
| CN107843789B (en) * | 2017-11-02 | 2020-02-28 | 国家电网公司 | Integral aging test method for transformer winding |
| CN110275095A (en) * | 2019-06-12 | 2019-09-24 | 国网浙江省电力有限公司电力科学研究院 | Transformer insulated accelerated deterioration simulator and method |
| CN111371069B (en) * | 2020-04-14 | 2023-01-13 | 攀钢集团西昌钢钒有限公司 | Overtemperature protection device for transformer |
| CN112748150B (en) * | 2021-01-08 | 2024-08-13 | 国网宁夏电力有限公司电力科学研究院 | Converter transformer gas production rule monitoring device and working method |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2099967U (en) * | 1991-09-04 | 1992-03-25 | 铁道部科学研究院机车车辆研究所 | Thermometer in transformer inner |
| WO2009026038A1 (en) * | 2007-08-16 | 2009-02-26 | Radian Research, Inc. | Instrument transformer test equipment and method |
| CN102096030A (en) * | 2010-12-10 | 2011-06-15 | 西安交通大学 | Method for estimating residual insulation service life of power transformer based on operating data |
| CN203232031U (en) * | 2013-05-15 | 2013-10-09 | 国家电网公司 | Transformer oil and insulation paper aging test simulation test device |
| CN104181424A (en) * | 2014-08-26 | 2014-12-03 | 重庆大学 | Test device and test method for electric heat joint aging of transformer winding |
| CN205539288U (en) * | 2016-04-22 | 2016-08-31 | 重庆大学 | Simulate thermal ageing test device under transformer winding overload condition |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6714022B2 (en) * | 2001-02-20 | 2004-03-30 | Gary Hoffman | Apparatus and method for cooling power transformers |
-
2016
- 2016-04-22 CN CN201610256144.2A patent/CN105759153B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2099967U (en) * | 1991-09-04 | 1992-03-25 | 铁道部科学研究院机车车辆研究所 | Thermometer in transformer inner |
| WO2009026038A1 (en) * | 2007-08-16 | 2009-02-26 | Radian Research, Inc. | Instrument transformer test equipment and method |
| CN102096030A (en) * | 2010-12-10 | 2011-06-15 | 西安交通大学 | Method for estimating residual insulation service life of power transformer based on operating data |
| CN203232031U (en) * | 2013-05-15 | 2013-10-09 | 国家电网公司 | Transformer oil and insulation paper aging test simulation test device |
| CN104181424A (en) * | 2014-08-26 | 2014-12-03 | 重庆大学 | Test device and test method for electric heat joint aging of transformer winding |
| CN205539288U (en) * | 2016-04-22 | 2016-08-31 | 重庆大学 | Simulate thermal ageing test device under transformer winding overload condition |
Non-Patent Citations (2)
| Title |
|---|
| Life Prediction for Epoxy Resin Insulated Transformer Windings through Accelerated Aging Tests;Qikai Zhuang 等;《2010 International Conference on Solid Dielectrics》;20100709;第1-4页 * |
| 牵引负荷对变压器绝缘老化和寿命损失的影响;周利军 等;《电力系统自动化》;20050925;第29卷(第18期);第90-94页 * |
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