CN111398752A - Power transformer partial discharge positioning device and method based on multi-detector information fusion - Google Patents
Power transformer partial discharge positioning device and method based on multi-detector information fusion Download PDFInfo
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- CN111398752A CN111398752A CN202010270435.3A CN202010270435A CN111398752A CN 111398752 A CN111398752 A CN 111398752A CN 202010270435 A CN202010270435 A CN 202010270435A CN 111398752 A CN111398752 A CN 111398752A
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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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- G01S15/00—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems
- G01S15/02—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems using reflection of acoustic waves
- G01S15/06—Systems determining the position data of a target
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Abstract
The invention relates to a power transformer partial discharge positioning device and method for multi-detector information fusion, wherein the device comprises a high-frequency current transformer, an ultrasonic sensor and a detection host, wherein the high-frequency current transformer is arranged on a grounding down-lead of an iron core of a power transformer to be detected and a grounding down-lead of a clamping piece; the method has the characteristics of high real-time performance, good economical efficiency, strong exemplary performance and high expansibility.
Description
Technical Field
The invention belongs to the technical field of transformer fault diagnosis, particularly relates to positioning analysis and diagnosis of partial discharge inside a power transformer, and particularly relates to a power transformer partial discharge positioning device and method based on multi-detector information fusion.
Background
The power transformer is one of the most important electrical devices in the power system, and the good operation state of the power transformer is an important factor for ensuring the safety and stability of the whole power grid, and once the power transformer is abnormally operated, the power transformer can cause large-area damage to the power system. For example, when one junction transformer fails, a large-area power failure of the power grid may be caused, and the safe operation of the power grid is seriously affected. Therefore, the research of the practical and effective power transformer operation evaluation technology has important significance for safe and stable operation of the power grid.
In recent years, with the increase of voltage class of power systems, the insulation problem of power transformers is more and more prominent. According to the statistical data, the accidents caused by the insulation aging of the transformer account for more than 80 percent of the total accidents of the transformer. A large number of practical cases have demonstrated that failure of a power transformer is often caused by problems with its insulation system. At present, with the development of a power grid, the state maintenance replaces the traditional regular maintenance and becomes the main mode of equipment maintenance. The live detection of the power transformer can find hidden dangers in operation of the power transformer in time after the power transformer is abnormal in operation, and is an important means for evaluating the operation state of the power transformer. However, for the insulation defect problem of large power equipment such as a power transformer, the existence of hidden danger needs to be diagnosed, and the discharge part needs to be detected so as to be convenient for targeted maintenance and repair, thereby saving the time and cost of repair and reducing the power failure loss of a power grid. For a long time, effective charged detection and analysis methods and equipment are lacked in the positioning diagnosis of partial discharge in the power transformer. Therefore, effective power transformer operation state evaluation and hidden danger elimination technical research are developed, and the method has important practical significance for further ensuring the reliability and safety of power grid operation.
At present, the existing transformer live detection devices at home and abroad are generally special detection devices, only single detection means such as high frequency, ultrasonic, ultrahigh frequency, vibration and the like can be adopted for directional diagnosis and detection, various state parameter information cannot be integrated, data including information measured by equipment is fully mined, and the local discharge in a power transformer is more difficult to perform positioning diagnosis, so that potential faults of the transformer cannot be timely and effectively evaluated, and the traditional defect of excessive maintenance cannot be effectively avoided.
Disclosure of Invention
The invention aims to solve the technical problem of providing a power transformer partial discharge positioning device and method based on multi-detector information fusion, and solving the defects of long time consumption, low accuracy and insufficient data utilization of the traditional positioning diagnosis by adopting a single detection technology.
The technical scheme adopted by the invention is as follows: a power transformer partial discharge positioning device based on multi-detector information fusion comprises a high-frequency current transformer, an ultrasonic sensor and a detection host, wherein the high-frequency current transformer is arranged on a grounding down-lead of an iron core of a power transformer to be detected and a grounding down-lead of a clamping piece, the ultrasonic sensor is arranged on one side surface of the power transformer to be detected, and the detection host is connected with the high-frequency current transformer and the ultrasonic sensor.
Furthermore, the ultrasonic sensors are arranged on one side surface of the power transformer to be detected in a 3 × 3 array mode, and the ultrasonic sensors are connected with the detection host through leads.
Further, a plurality of the ultrasonic sensors are located on the same plane.
Furthermore, the two high-frequency current transformers are respectively positioned on the grounding down-lead of the iron core of the power transformer to be tested and the grounding down-lead of the clamping piece.
Furthermore, the detection host comprises a signal receiving and collecting unit and a signal processing and analyzing unit, and the high-frequency current transformer and the ultrasonic sensor are connected with the signal receiving and collecting unit.
Further, the power frequency phase detection device further comprises a power frequency phase detection unit for acquiring power frequency information.
Furthermore, the power frequency phase detection unit is connected with a signal receiving and collecting unit of the detection host.
Furthermore, the signal receiving and collecting unit completes signal amplification and filtering processing and outputs the signal to the signal processing and analyzing unit.
A method for locating partial discharge of a power transformer based on multi-detector information fusion comprises the following steps:
arranging a high-frequency current transformer on a grounding down-lead of an iron core of a power transformer to be detected and a grounding down-lead of a clamping piece, and detecting a high-frequency pulse current signal of the transformer;
arranging ultrasonic sensors on one side surface of a power transformer to be measured in a 3 × 3 array mode, enabling a plurality of ultrasonic sensors to be located on the same plane, and establishing position coordinates of the ultrasonic sensors by taking the ultrasonic sensor at the central position as a coordinate 0 point;
taking the time point when the ultrasonic sensor detects the discharge characteristic as the initial moment, and recording the time t when each high-frequency current transformer detects the discharge characteristiciSpherical equation for ultrasonic propagation distance and time delay is established by taking each detector as unit
Fi＝(x-xi)2+(y-yi)2+(z-zi)2-(v·ti)2＝0 (i＝1,2,3...9) (1)
Wherein x isi、yi、ziRespectively is the set value of the spatial position of the ith ultrasonic sensor, tiV is the equivalent propagation speed of the ultrasonic wave at the moment when each sensor detects the partial discharge ultrasonic signal;
and (4) integrating coordinate calculation results (x, y and z) of the 9 ultrasonic sensors, so that the positioning of the partial discharge position can be realized.
Furthermore, formula (1) is solved by adopting a least square fitting mode, and the mathematical model is as follows:
spherical equation FiWith 4 real arguments (x)i,yi,zi,ti) And 4 parameters (x, y, z, v) to be determined, for determining the location of the discharge source (x, y, z), the objective function (x, y, z, v) being chosen to be FiThe sum of the squares of the residuals, i.e.
Thus, (x, y, z) can be obtained.
The invention has the positive effects that:
(1) the method has high real-time performance, comprehensively utilizes two detection modes of high frequency and ultrasound, overcomes the defects of difficult partial discharge positioning, long positioning time consumption and dependence on a large number of sensors in a single detection mode, and quickly performs defect positioning analysis.
(2) The method has good economy, greatly reduces the number of ultrasonic sensors which are required to be relied on in the prior positioning technology, reduces the manufacturing cost of the positioning device, and has better economy.
(3) The method has strong exemplary performance, and provides a new idea and positive demonstration for subsequently developing the multi-parameter information state diagnosis of the transformer by comprehensively developing the partial discharge defect diagnosis analysis by combining various principle detection modes.
(4) The method has high expansibility, and can further integrate more transformer state detection quantities through algorithm development and program programming, further improve the partial discharge defect positioning calculation speed and further improve the manufacturing cost.
Drawings
FIG. 1 is a schematic view of the apparatus of the present invention;
FIG. 2 is a layout diagram of the high frequency current transformer of the present invention;
FIG. 3 is a diagram of an ultrasonic sensor arrangement of the present invention;
fig. 4 is a schematic diagram of the device of the present invention.
In the drawings;
1-iron core grounding down lead;
2-the clip is grounded and the down lead is connected;
3-a high-frequency current transformer;
4-a transformer to be tested;
5-detecting the host machine;
pi-ultrasonic sensor.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the application, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.
The relative arrangement of the components and steps, the numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present application unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.
The invention records multi-path partial discharge ultrasonic signals by combining partial discharge signals in the power transformer detected by a high-frequency sensor and an ultrasonic sensor and taking the high-frequency pulse current signals of partial discharge as a trigger reference clock, and measures the time t of the ultrasonic signalsiThe propagation time from the partial discharge point to each sensor is determined by multiplying the propagation speed v of the ultrasonic wave by the time delay tiThe spatial distance from the discharge fault point to each sensor is obtained, so that the geometric position of the discharge fault point is obtained; the method comprises the steps of developing a power transformer partial discharge positioning device based on multi-detector information fusion, including two-channel high-frequency signal detection and nine-channel ultrasonic signal detection, solving an equation set, and calculating and testing a power transformer partial discharge position coordinate.
As shown in fig. 1-4, the power transformer partial discharge positioning device based on multi-detector information fusion of the present invention includes a high frequency current transformer 3 disposed on an iron core grounding down-lead 1 and a clamp grounding down-lead 2 of a power transformer 4 to be detected, an ultrasonic sensor Pi disposed on one side of the power transformer 4 to be detected, and a detection host 5 connected to the high frequency current transformer and the ultrasonic sensor.
The detection host 5 comprises a signal receiving and collecting unit and a signal processing and analyzing unit, wherein the high-frequency current transformer and the ultrasonic sensor are connected with the signal receiving and collecting unit, and the signal receiving and collecting unit completes signal amplification and filtering processing and outputs the signal to the signal processing and analyzing unit.
The ultrasonic sensors are contact ultrasonic detectors, are arranged in a three-row three-column array mode, are arranged on one side face, with a large area, of a box body of the power transformer to be detected, are located on the same plane, and are arranged to avoid the position, with reinforcing ribs, of the transformer to be detected, and are connected with the detection host through leads.
The two high-frequency current transformers are respectively positioned on the iron core grounding down-lead 1 and the clamping piece grounding down-lead 2 of the power transformer to be detected, and the high-frequency current transformers have the capacity of detecting weak high-frequency current, and the detection frequency band is 3MHz-30 MHz.
The power frequency phase detection unit is connected with a signal receiving and collecting unit of the detection host.
A method for locating partial discharge of a power transformer based on multi-detector information fusion comprises the following steps:
arranging a high-frequency current transformer on a grounding down-lead of an iron core of a power transformer to be detected and a grounding down-lead of a clamping piece, and detecting a high-frequency pulse current signal of the transformer; velocity of propagation V due to electric signal0＝3x108m/s is far greater than the propagation velocity V of the ultrasonic wave11400m/s, and adopting a partial discharge high-frequency signal as a trigger time; and the two paths of high-frequency pulse current detection paths take the moment of preferentially measuring the partial discharge high-frequency pulse current as the trigger moment.
The ultrasonic sensors are arranged on a certain side face of the power transformer to be detected in a 3 × 3 array mode, the ultrasonic sensors are located on the same plane, and the ultrasonic sensors are connected to a detection host through leads.
And establishing the position coordinates of each ultrasonic sensor by taking the ultrasonic sensor at the central position as a coordinate 0 point, wherein the plurality of ultrasonic sensors are positioned in the same coordinate system.
Taking the time point when the ultrasonic sensor detects the discharge characteristic as the initial moment, and recording the time t when each high-frequency current transformer detects the discharge characteristiciSpherical equation for ultrasonic propagation distance and time delay is established by taking each detector as unit
Fi＝(x-xi)2+(y-yi)2+(z-zi)2-(v·ti)2＝0 (i＝1,2,3...9) (1)
Wherein x isi、yi、ziRespectively is the set value of the spatial position of the ith ultrasonic sensor, tiV is the equivalent propagation speed of the ultrasonic wave at the moment when each sensor detects the partial discharge ultrasonic signal;
fitting method by using least square methodFormula (I), i.e. selecting the objective function (x, y, z, v) as FiThe solution of the equation is obtained by minimizing the target function (x, y, z, v) through a fitting algorithm;
the obtained (x, y, z) physical meaning is horizontal, vertical and radial depth coordinates of the discharge source relative to the reference point Pi, and the coordinate calculation results of the 9 detection points are integrated, so that the localization of the partial discharge defect part can be realized.
Solving the mathematical model of formula (1) by using a least square fitting method is as follows:
spherical equation FiWith 4 real arguments (x)i,yi,zi,ti) And 4 parameters (x, y, z, v) to be determined, for determining the location of the discharge source (x, y, z), the objective function (x, y, z, v) being chosen to be FiThe sum of the squares of the residuals, i.e.
Thus, (x, y, z) can be obtained.
The purpose of the least squares fit is to determine (x, y, z, v) such that the objective function (x, y, z, v) is minimized.
The calculation result is as follows:
a. the source is offset by a distance x horizontally from the reference point Pi.
b. The offset distance y of the discharge source with respect to the direction perpendicular to the reference point Pi.
c. The offset distance z of the discharge source to the inside of the tank with respect to the reference point Pi.
d. The equivalent ultrasonic sound velocity v from the discharge source to the measurement point.
Claims (10)
1. A power transformer partial discharge positioning device based on multi-detector information fusion is characterized by comprising a high-frequency current transformer, an ultrasonic sensor and a detection host, wherein the high-frequency current transformer is arranged on a grounding down-lead of an iron core of a power transformer to be detected and a grounding down-lead of a clamping piece, the ultrasonic sensor is arranged on one side surface of the power transformer to be detected, and the detection host is connected with the high-frequency current transformer and the ultrasonic sensor.
2. The power transformer partial discharge positioning device based on multi-detector information fusion as claimed in claim 1, wherein the ultrasonic sensors are arranged in a 3 × 3 array on one side of the power transformer to be detected, and the plurality of ultrasonic sensors are connected with the detection host through leads.
3. The power transformer partial discharge positioning device based on multi-detector information fusion as claimed in claim 2, characterized in that a plurality of the ultrasonic sensors are located on the same plane.
4. The power transformer partial discharge positioning device based on multi-detector information fusion as claimed in claim 1, wherein there are two high-frequency current transformers respectively located on the core grounding down-lead and the clip grounding down-lead of the power transformer to be tested.
5. The power transformer partial discharge positioning device based on multi-detector information fusion as claimed in claim 1, wherein the detection host comprises a signal receiving and collecting unit and a signal processing and analyzing unit, and the high-frequency current transformer and the ultrasonic sensor are both connected with the signal receiving and collecting unit.
6. The power transformer partial discharge positioning device based on multi-detector information fusion as claimed in claim 5, characterized by further comprising a power frequency phase detection unit for obtaining power frequency information.
7. The power transformer partial discharge positioning device based on multi-detector information fusion as claimed in claim 6, characterized in that the power frequency phase detection unit is connected with a signal receiving and collecting unit of a detection host.
8. The power transformer partial discharge positioning device based on multi-detector information fusion as claimed in claim 7, wherein the signal receiving and collecting unit performs signal amplification and filtering processing and outputs the processed signal to the signal processing and analyzing unit.
9. A power transformer partial discharge positioning method based on multi-detector information fusion is characterized by comprising the following steps:
arranging a high-frequency current transformer on a grounding down-lead of an iron core of a power transformer to be detected and a grounding down-lead of a clamping piece, and detecting a high-frequency pulse current signal of the transformer;
arranging ultrasonic sensors on one side surface of a power transformer to be measured in a 3 × 3 array mode, enabling a plurality of ultrasonic sensors to be located on the same plane, and establishing position coordinates of the ultrasonic sensors by taking the ultrasonic sensor at the central position as a coordinate 0 point;
taking the time point when the ultrasonic sensor detects the discharge characteristic as the initial moment, and recording the time t when each high-frequency current transformer detects the discharge characteristiciSpherical equation for ultrasonic propagation distance and time delay is established by taking each detector as unit
Fi＝(x-xi)2+(y-yi)2+(z-zi)2-(v·ti)2＝0 (i＝1,2,3...9) (1)
Wherein x isi、yi、ziRespectively is the set value of the spatial position of the ith ultrasonic sensor, tiV is the equivalent propagation speed of the ultrasonic wave at the moment when each sensor detects the partial discharge ultrasonic signal;
and (4) integrating coordinate calculation results (x, y and z) of the 9 ultrasonic sensors, so that the positioning of the partial discharge position can be realized.
10. The power transformer partial discharge positioning method based on multi-detector information fusion as claimed in claim 9, characterized in that the least square fitting method is adopted to solve the formula (1), and the mathematical model is:
spherical equation FiWith 4 real arguments (x)i,yi,zi,ti) And 4 parameters (x, y, z, v) to be determined, for determining the position of the discharge source (x, y, z), the target being selectedThe scaling function (x, y, z, v) is FiThe sum of the squares of the residuals, i.e.
Thus, (x, y, z) can be obtained.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN112798907A (en) * | 2020-12-18 | 2021-05-14 | 浙江中新电力工程建设有限公司 | Multi-sensor partial playing sound signal phase detection circuit |
| CN114113951A (en) * | 2021-12-16 | 2022-03-01 | 国网山东省电力公司烟台供电公司 | Ultrasonic stress detection system and method for insulation defect of high-voltage switch cabinet |
| CN115575770A (en) * | 2022-11-23 | 2023-01-06 | 南方电网数字电网研究院有限公司 | Partial discharge signal positioning method, device, terminal and storage medium |
-
2020
- 2020-04-08 CN CN202010270435.3A patent/CN111398752A/en active Pending
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| 邢伟娜: "《电力变压器局部放电检测技术的研究与设计》", 《中国优秀博硕士学位论文全文数据库(硕士)工程科技Ⅱ辑》 * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112798907A (en) * | 2020-12-18 | 2021-05-14 | 浙江中新电力工程建设有限公司 | Multi-sensor partial playing sound signal phase detection circuit |
| CN112798907B (en) * | 2020-12-18 | 2024-04-16 | 浙江中新电力工程建设有限公司 | Multi-sensor partial discharge sound signal phase detection circuit |
| CN114113951A (en) * | 2021-12-16 | 2022-03-01 | 国网山东省电力公司烟台供电公司 | Ultrasonic stress detection system and method for insulation defect of high-voltage switch cabinet |
| CN114113951B (en) * | 2021-12-16 | 2023-09-05 | 国网山东省电力公司烟台供电公司 | Ultrasonic stress detection system and method for insulation defect of high-voltage switch cabinet |
| CN115575770A (en) * | 2022-11-23 | 2023-01-06 | 南方电网数字电网研究院有限公司 | Partial discharge signal positioning method, device, terminal and storage medium |
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