CN106771924A - A kind of utilization photoelectricity field sensor detects the detecting system and method for defects of insulator - Google Patents

Abstract

The invention discloses a detection system and method for detecting insulator defects by using a photoelectric field sensor, which includes a photoelectric field sensor, a lifting platform and an electric field measuring instrument. The photoelectric field sensor is installed on the lifting platform and connected with the electric field measuring instrument connected, and the photoelectric field sensor is arranged around the insulator string. The advantages of the present invention are: the instrument is simple, the requirements for the external environment such as weather are very low, and there are many measurement points; at the same time, the method of the present invention has the advantages of no need to touch the insulator string, no need to climb the tower, and short detection time, and replaces it with calculation. Partial measurement work, so the workload is small, which is beneficial to the use of operation and maintenance personnel; in addition, the change of ambient temperature does not affect the judgment of insulator deterioration, and in dry conditions, the pollution of the insulator surface does not affect the judgment of insulator deterioration.

Description

A detection system and method for detecting insulator defects using a photoelectric field sensor

technical field

The invention relates to a method and system for detecting insulator defects, in particular to a method and system for detecting insulator defects by using a photoelectric field sensor.

Background technique

With the rapid development of the modern electric power industry towards large units, large capacity and high voltage, the operating conditions are more stringent, and the defect rate is gradually increasing. The reliability of the equipment has put forward higher and higher requirements. As an important part of the power transmission and transformation system, the on-line detection and defect diagnosis of the insulator's operating status are particularly important. In order to solve the detection problem of degraded insulators, a variety of detection methods have been studied at home and abroad. At present, the common methods for detecting the defects of synthetic insulators of high-voltage transmission lines are as follows:

1. Use a high-powered telescope to visually inspect. Since the size of general defects is small and needs to be observed from a certain angle, observation from the ground is not reliable enough, so it is required to go to the tower for inspection. In addition, internal insulation faults are difficult to find by observation alone.

2. Another method for on-site detection of low-zero value suspension insulators on high-voltage transmission lines. The common tool is a spark fork. If the performance is good, the insulator will be broken down under pressure and spark discharge will occur. The operator judges whether the insulator is good or not according to the sound of spark discharge. This method is limited by the background light noise, and cannot monitor long-distance insulators. It will cause danger when a good insulator is short-circuited, and it cannot detect composite insulators.

3. The sound wave method detects the sound wave emitted by the partial discharge of the insulator, and its sensitivity is lower than that of the infrared imaging method. In the actual inspection process, corona often occurs in the high-voltage end fittings, and the background noise generated will overwhelm the sound waves emitted by the insulator defects.

4. Infrared temperature measurement method, the damage of insulating materials caused by electric field is mostly related to temperature. Partial discharge, dielectric loss or resistive loss when leakage current flows through the insulating material can cause the local temperature of the insulator to rise. This method is greatly affected by the environment, the interference of the sun and background radiation, the selection of the spectral emissivity e, the focusing situation, and meteorological conditions will all affect the detection results.

Therefore, there are still some limitations in the practical application of detecting defects of composite insulators of high-voltage transmission lines.

Contents of the invention

The object of the present invention is to provide a method and system for detecting insulator defects using a photoelectric field sensor, which is simple in operation, widely used and accurate in detection.

In order to achieve the above purpose, a detection system designed by the present invention to detect insulator defects using a photoelectric field sensor includes a photoelectric field sensor, a lifting platform and an electric field measuring instrument. The photoelectric field sensor is installed on the lifting platform and is connected to the The electric field measuring instrument is connected, and the photoelectric field sensor is arranged around the insulator string.

Further, the lifting platform includes an insulating ring, an insulating rod and an insulating rope, the insulating ring is fixed on the top of the insulating rod, and one end of the insulating rope passes through the insulating ring and is connected to the photoelectric field sensor .

Furthermore, the distance from the probe of the photoelectric field sensor to the shed edge of each insulator in the insulator string is the same.

As a preferred option, the photoelectric field sensor simultaneously measures the electric field values in the three directions of X, Y and Z around the insulator string and synthesizes the electric field values in the three directions of X, Y and Z.

A method for detecting insulator defects using a photoelectric field sensor, comprising the following steps:

1) arrange photoelectric field sensors around the insulator string;

2) Move the photoelectric field sensor along the insulator string, and record the electric field value measured by the photoelectric field sensor at multiple preset points around the insulator string;

3) Judging the defects of the insulators in the insulator string according to the electric field values at multiple preset points.

Further, the step 2 is specifically,

2.1) Confirm that the photoelectric field sensor is correctly arranged around the insulator string;

2.2) Aim the probe of the photoelectric field sensor at the first insulator shed at the high voltage end of the insulator string, move the photoelectric field sensor along the high voltage end to the low voltage end of the insulator string, and record the measured values of the photoelectric field sensor at multiple preset points in sequence. first electric field value;

2.3) moving the photoelectric field sensor along the low-voltage end to the high-voltage end of the insulator string, and sequentially recording the second electric field values measured by the photoelectric field sensor at multiple preset points;

2.4) Calculate the average of the first electric field values of the multiple preset points and the second electric field values corresponding to the preset points respectively, to obtain the electric field values of the multiple preset points.

Further, the step 2.1 is specifically:

2.1) Move the photoelectric field sensor to the high-voltage end of the insulator string, and observe whether there is discharge or abnormal corona phenomenon at the high-voltage end of the insulator string. If there is no discharge or abnormal corona phenomenon, the photoelectric field sensor is arranged around the insulator string correctly.

As a preference, the step 3 is specifically:

3) Draw the electric field intensity distribution curve around the insulator string according to the electric field values at multiple preset points, and judge the defects of the insulators in the insulator string. The electric field intensity distribution curve around the insulator string is the electric field change rate curve in the spatial axis of the insulator string.

As a preference, the step 3 is specifically:

3) Draw the electric field intensity distribution curve around the insulator string according to the electric field values at multiple preset points, and judge the defects of the insulators in the insulator string, the electric field intensity distribution curve around the insulator string is the electric field change rate curve in the space axis of the insulator string The electric field values of multiple preset points are simulated and analyzed by the finite element simulation method to analyze the electric field distribution of the insulator string, and the defects of the insulators in the insulator string are judged.

As a preferred option, the number of preset points is 13.

The advantage of the present invention is that it can propose a method for detecting degraded insulators by using a photoelectric field sensor to measure the axial electric field distribution on the surface of the insulator string on the basis that degraded insulators have a great influence on the spatial axial electric field component. The change of axial electric field in string space can determine the deteriorated insulator and its position. The method of the present invention uses relatively simple instruments, has very low requirements on the external environment such as weather, and has many measurement points; at the same time, the method of the present invention has the advantages of no need to touch insulator strings, no need to climb towers, and short detection time. Partial measurement work, so the workload is small, which is beneficial to the use of operation and maintenance personnel; in addition, in the method of the present invention, the change of ambient temperature does not affect the judgment of insulator deterioration, and in dry conditions, the pollution on the surface of the insulator does not affect the insulator Judgment of deterioration.

Description of drawings

Fig. 1 is the use state schematic diagram of the present invention;

Fig. 2 is a schematic diagram of the method steps of the present invention;

Fig. 3 is a schematic diagram of the electric field distribution relationship between a good insulator string and a deteriorated insulator string;

Figure 4 is a diagram of the test and simulation results of cleaning the insulator string;

Fig. 5 is a schematic diagram of the influence of the position of the degraded insulator on the rate of change of the spatial axial electric field when d=0.3 and 0.5m respectively.

In the figure: photoelectric field sensor 1, lifting platform 2, electric field measuring instrument 3, insulator string 4, insulating ring 5, insulating rod 6, insulating rope 7.

detailed description

Below in conjunction with accompanying drawing and specific embodiment the present invention will be described in further detail:

As shown in Figures 1 to 2, a detection system for detecting insulator defects using a photoelectric field sensor includes a photoelectric field sensor 1, a lifting platform 2 and an electric field measuring instrument 3, and the photoelectric field sensor 1 is installed on the lifting platform 2 And connected with the electric field measuring instrument 3 , and the photoelectric field sensor 1 is arranged around the insulator string 4 . Described lifting platform 2 comprises insulating ring 5, insulating rod 6 and insulating rope 7, and described insulating ring 5 is fixed on the top of described insulating rod 6, and one end of described insulating rope 7 passes through described insulating ring 5 and is connected with the The photoelectric field sensor 1 is connected. The distance from the probe of the photoelectric field sensor 1 to the shed edge of each insulator in the insulator string 4 is the same. The photoelectric field sensor 1 simultaneously measures the electric field values in the three directions of X, Y and Z around the insulator string 4 and synthesizes the electric field values in the three directions of X, Y and Z.

A method for detecting insulator defects using a photoelectric field sensor, comprising the following steps:

1) arrange photoelectric field sensors 1 around the insulator string 4;

2) Move the photoelectric field sensor 1 along the insulator string 4, and record the electric field value measured by the photoelectric field sensor 1 at a plurality of preset points around the insulator string 4, the number of the preset points is 13;

2.1) Confirm that the photoelectric field sensor 1 is correctly arranged around the insulator string 4: move the photoelectric field sensor 1 to the high-voltage end of the insulator string 4, and observe whether there is discharge or abnormal corona phenomenon at the high-voltage end of the insulator string 4. If there is no discharge or Abnormal corona phenomenon, the photoelectric field sensor 1 is correctly arranged around the insulator string 4;

2.2) Align the probe of the photoelectric field sensor 1 with the first insulator shed at the high-voltage end of the insulator string 4, and move the photoelectric field sensor 1 along the high-voltage end to the low-voltage end of the insulator string 4, and record in turn the photoelectric field sensor 1 in multiple The first electric field value measured at the preset point;

2.3) moving the photoelectric field sensor 1 along the low-voltage end to the high-voltage end of the insulator string 4, and sequentially recording the second electric field values measured by the photoelectric field sensor 1 at a plurality of preset points;

2.4) Calculate the average of the first electric field values of the multiple preset points and the second electric field values corresponding to the preset points respectively, to obtain the electric field values of the multiple preset points.

3) Judging the defects of the insulators in the insulator string 4 according to the electric field values of multiple preset points: drawing the electric field intensity distribution curve around the insulator string 4 according to the electric field values of multiple preset points, and judging the defects of the insulators in the insulator string 4, The electric field intensity distribution curve around the insulator string 4 is the electric field change rate curve of the spatial axial direction of the insulator string 4, and the electric field values at multiple preset points are simulated and analyzed on the electric field distribution law of the insulator string 4 using a finite element simulation calculation method, Defects of the insulators in the insulator string 4 are judged.

Example 1:

During detection, the photoelectric sensor 1 is fixed at a certain distance from the surface of the insulator string 4 through the insulating ring 5, the insulating rod 6 and the insulating rope 7, so that the photoelectric sensor 1 can move synchronously with the insulating rope 7, and the photoelectric sensor 1 is connected to the electric field through the optical fiber. Meter 3 is connected. Photoelectric field sensor 1 is a sensor based on the Pockels effect. The electro-optic crystal with good insulation performance is used as the sensing element on the side; the optical fiber with high insulation strength is used as the signal transmission channel, so that the insulation structure is greatly simplified, and there is no iron core and coil. , There is no magnetic saturation, ferromagnetic resonance and other problems, which can improve the measurement accuracy.

A kind of method design principle of utilizing photoelectric field sensor to detect insulator defect of the present invention is as follows:

Figure 3 is a schematic diagram of the electric field distribution curve between a good insulator string and a deteriorated insulator string. The horizontal axis is the position of the insulator string, from left to right is from the low voltage end to the high voltage end of the insulator string, and the vertical axis is the electric field intensity. One curve is curve A, and the next curve is curve B; curve B is the change curve of electric field strength along the axial direction of a good insulator string calculated according to the electromagnetic field theory. Under normal circumstances, the curve is smooth and has a "U" shape; When there is a continuity defect in the insulator string (see the circle in Figure 3), the potential at the defect becomes a constant. Since the electric field strength is the rate of change of the potential along the length, the electric field strength at the defect will suddenly decrease. The electric field distribution curve is no longer smooth, but distorted at the corresponding position, as shown in the curve A in Figure 3. The shape of the curve A is "sag in the middle and rise at both ends".

This specific embodiment simulates the actual operation of a 220kV line. The effective value of the added AC voltage is 127.0kV, the simulated wire length is 5.0m, the insulation resistance of the low-value insulator string used in the test is 40MΩ, and the zero-value insulator string adopts a ground wire short-circuit steel foot A steel cap is used to simulate, and the short ground wire faces away from the probe of the photoelectric field sensor when measuring.

Figure 4 is a diagram of the test and simulation results of cleaning the insulator string, and d in the figure is the distance from the electric field measurement reference line or measurement reference point to the central axis of the insulator string. The numbers of the insulators from the high voltage end to the low voltage end are No.1~No.13 in sequence. It can be seen from Figure 4 that the measured values are slightly lower than the calculated values at most locations, but the variation rules of the two are basically consistent. This proves that it is feasible to use the finite element simulation calculation method to simulate and analyze the electric field distribution law of the porcelain insulator string.

In the present invention, the influence of the degradation position and distance d on the change of the space electric field is analyzed by the rate of change of the space axial electric field σ _i,j , the expression of which is:

σ _i,j = ΔE _i,j,f -ΔE _i,S /ΔE _i

In the formula: i is the position of each insulator; j is the position of the deteriorated insulator (i, j=1~13); f represents the insulator string containing the deteriorated insulator; S represents the good insulator string.

Figure 5 shows the influence of the position of the degraded insulator on the rate of change of the spatial axial electric field when d=0.3 and 0.5m, and it can be seen that the test results are basically consistent with the simulation results. The degraded insulator has the greatest influence on the spatial axial electric field component. The farther the measurement distance is, the smaller the rate of change of the spatial axial electric field is. The rate of change of the space electric field is the smallest and basically remains unchanged; the rate of change of the space electric field increases when it is close to the low-voltage end. When d=0.30m, the minimum electric field change rate is 0.13; when d=0.50m, the minimum electric field change rate is 0.04. It can be seen that as the distance d increases, the rate of change of the space electric field at the position of the degraded insulator gradually decreases. The distance between the sensor head and the insulator is within 10cm or less, and the measured electric field distribution curve is close to the theoretical U-shaped distribution, and it is very smooth.

Table 1

As shown in Table 1, when d=0.3m, the spatial axial electric field change rate of No.11, No.12, No.13 insulators. It can be seen from Table 1 that when the degraded insulator is at any position in the string, the rate of change of the spatial axial electric field around the three insulators on the crossarm side is basically stable, and the rate of change of the spatial axial electric field of at least two of the three insulators is greater than 5.0%. . Based on the idea of the sensitive insulator method, the present invention defines three insulators on the cross-arm side as a sensitive insulator group, and by measuring the spatial axial electric field change rate of these three insulators, it can be judged whether there are zero-value insulators in the insulator string. Therefore, for the 220kV line suspension insulator string, it is only necessary to analyze the spatial axial electric field change rate of the three insulators at the low-voltage end to determine whether the insulator string contains zero-value insulators.

The present invention proposes a method for detecting degraded insulators by using a photoelectric field sensor to measure the axial electric field distribution on the surface of the insulator string on the basis of the fact that degraded insulators have a great influence on the spatial axial electric field component. Changes can identify degraded insulators and their location. The method of the present invention uses relatively simple instruments, has very low requirements on the external environment such as weather, and has many measurement points; at the same time, the method of the present invention has the advantages of no need to touch insulator strings, no need to climb towers, and short detection time. Partial measurement work, so the workload is small, which is beneficial to the use of operation and maintenance personnel; in addition, in the method of the present invention, the change of ambient temperature does not affect the judgment of insulator deterioration, and in dry conditions, the pollution on the surface of the insulator does not affect the insulator Judgment of deterioration.

Finally, it should be pointed out that the above embodiments are only representative examples of the present invention. Obviously, the present invention is not limited to the above-mentioned embodiments, and many variations are possible. All simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention shall be deemed to belong to the protection scope of the present invention.

Claims (10)

1. a kind of utilization photoelectricity field sensor detects the detecting system of defects of insulator, it is characterised in that：Including optical electric field sensing Device (1), hoistable platform (2) and electric field measuring apparatus (3), the photoelectricity field sensor (1) on the hoistable platform (2) simultaneously It is connected with the electric field measuring apparatus (3), and the photoelectricity field sensor (1) is arranged in around insulator chain (4).

2. a kind of utilization photoelectricity field sensor according to claim 1 detects the detecting system of defects of insulator, its feature It is：The hoistable platform (2) includes dead ring (5), insulating bar (6) and insulating cord (7), and the dead ring (5) is fixed on institute State the top of insulating bar (6), one end of the insulating cord (7) through the dead ring (5) and with the photoelectricity field sensor (1) Connection.

3. a kind of utilization photoelectricity field sensor according to claim 2 detects the detecting system of defects of insulator, its feature It is：The distance at probe to each insulator umbrella edge in insulator chain (4) of the photoelectricity field sensor (1) is identical.

4. a kind of utilization photoelectricity field sensor according to any one in claims 1 to 3 detects the inspection of defects of insulator Examining system, it is characterised in that：The photoelectricity field sensor (1) is while measure around insulator chain (4) in tri- directions of X, Y and Z Electric field value and synthesis tri- electric field values in direction of X, Y and Z.

5. a kind of method that utilization photoelectricity field sensor detects defects of insulator, it is characterised in that：Comprise the following steps：

1) photoelectricity field sensor (1) is arranged around insulator chain (4)；

2) along insulator chain (4) moving photoconductor field sensor (1), and recording light electric-field sensor (1) is around insulator chain (4) The electric field value that multiple presets measure；

3) electric field value according to multiple presets judges the defect situation of insulator in insulator chain (4).

6. the method that a kind of utilization photoelectricity field sensor according to claim 5 detects defects of insulator, it is characterised in that： The step 2 specifically,

2.1) confirm that photoelectricity field sensor (1) arranges errorless around insulator chain (4)；

2.2) by the first insulator full skirt of alignment probe insulator chain (4) high-pressure side of photoelectricity field sensor (1), and along exhausted The high-pressure side of edge substring (4) to low-pressure end moving photoconductor field sensor (1), and successively recording light electric-field sensor (1) in multiple First electric field value of preset measurement；

2.3) along the low-pressure end of insulator chain (4) to high-pressure side moving photoconductor field sensor (1), and recording light electric field sensing successively The second electric field value that device (1) is measured in multiple presets；

2.4) the first electric field value of multiple presets is carried out into average computation with the second electric field value of corresponding preset respectively, is obtained The electric field value of multiple presets.

7. the method that one kind according to claim 6 detects defects of insulator using photoelectricity field sensor (1), its feature exists In：The step 2.1 is specially：

2.1) photoelectricity field sensor (1) is moved at the high-pressure side of insulator chain (4), the high-pressure side of observation insulator chain (4) Whether electric discharge or abnormal corona phenomenon are had, if not discharging or abnormal corona phenomenon, photoelectricity field sensor (1) is in insulation Arrange errorless around substring (4).

8. the one kind according to any one of claim 5~7 detects the side of defects of insulator using photoelectricity field sensor (1) Method, it is characterised in that：The step 3 is specially：

3) electric field value according to multiple presets draws insulator chain (4) surrounding electric field strength distribution curve, judges insulator chain (4) defect situation of insulator in, insulator chain (4) the surrounding electric field strength distribution curve is insulator chain (4) spatial axes To electric field change rate curve.

9. the method that the one kind according to claim 8 detects defects of insulator using photoelectricity field sensor (1), its feature It is：The step 3 is specially：

3) electric field value according to multiple presets draws insulator chain (4) surrounding electric field strength distribution curve, judges insulator chain (4) defect situation of insulator in, insulator chain (4) the surrounding electric field strength distribution curve is insulator chain (4) spatial axes To electric field change rate curve, by the electric field value of multiple presets using finite element stimulation method to insulator chain (4) Electric field distribution law carries out simulation analysis, judges the defect situation of insulator in insulator chain (4).

10. the method that the one kind according to claim 9 detects defects of insulator using photoelectricity field sensor (1), it is special Levy and be：The number of the preset is 13.