JPH0465657A - Device for detecting adhesion density of salt component - Google Patents

Abstract

PURPOSE:To detect only the salt component among the contaminating materials sticking to an insulator and to measure the adhesion density of the salt component by using a 1st optical waveguide for detecting the salt component by using a 1st optical waveguide for detecting the salt component and the contaminating materials of dust (calcium sulfate and kaolinite, etc.) and using a 2nd optical waveguide for detecting the dust. CONSTITUTION:The light emitted from a light source section 1 is introduced through optical fibers 6 to an optical branching filter 2 and is bisected by the optical branching filter 2. The respective branched beams are respectively passed through the optical fibers 6 to a detecting section 3 and is introduced to the 1st and 2nd optical waveguides 3a, 3b. The light beams experiencing the change in the light loss by the adhesion of the salt component and dust in the detecting section 3 are respectively introduced through the optical fibers 6 to photodetectors 4a, 4b constituting a photodetecting section 4 and are converted to the electrical outputs corresponding to the intensity of the transmitted light. A computing section 5 calculates the adhesion (adhesion density of the salt component) of only the salt component from the relational equation between the change rate of the intensity of the transmitted light and the adhesion of the contaminant per unit area which is previously known with the optical waveguides 3a, 3b in accordance with the change rate of the intensity of the transmitted light (i.e. the intensity of the transmitted light based on the case there is no adhesion in the detecting section 3) obtd. from the photodetectors 4a, 4b through signal cables 7, 7.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an apparatus for detecting the amount of salt adhering to the surface of an insulator and detecting the amount using an optical method.

[Prior Art] Insulators are widely used to ensure electrical insulation between high-voltage power transmission lines and support towers, but the environments in which lead is placed are harsh, such as in industrial areas. In coastal areas and other areas, the surface of the insulator is easily contaminated by salt (NaCl) and other inorganic dust, which can lower the dielectric strength of the insulator and cause flashover accidents. There is.

In order to prevent such a situation from occurring, it has been conventional practice to periodically quantitatively analyze the contaminants adhering to the surface of the insulator to determine the amount of contamination of the insulator.

By the way, in addition to salt, other contaminants that adhere to insulators include
It is said that there are 11 different substances, of which there are only 11 types, and among these, salt is a factor that significantly deteriorates the dielectric strength of insulators. Therefore, when displaying the amount of insulator fouling, it is convenient to use the amount of salt per unit area (equivalent salt adhesion amount) assuming that all of the fouling substances are made of salt.

Specific conventional methods are listed below.

(1) Brush washing method: A pilot insulator, which is made of the same material and shape as the insulator in actual use, is installed at the location where you want to measure the amount of contamination, and after a predetermined period of time, it is removed and the insulator is cleaned using a brush. The equivalent amount of salt deposited is determined by cleaning the contaminated material and measuring the electrical conductivity of the cleaning solution.

(2) Dew point type contamination measurement method: An electronic cooling element is incorporated into the pilot insulator, which is cooled to below the dew point temperature to collect moisture in the air and forcibly remove contaminants adhering to the insulator. The leakage resistance is measured in a wet state.Next, the leakage resistance obtained separately is calculated from the relationship with the equivalent salt deposition amount.

(3) Ultrasonic cleaning method for measuring the amount of contamination...The pilot insulator is placed in a cleaning tank containing distilled water, and while the insulator is rotated, the contaminants are washed away by ultrasonic cleaning, and the cleaning solution containing the contaminants is dissolved. Measure the electrical conductivity of and find the equivalent base quantity.

(4) Spherical simulated insulator method: A spherical simulated IIi insulator that slowly rotates on its own axis is always installed, and any contaminants adhering to it are wiped off with a wiper brush.

Contaminants adhering to the wiper brush are washed away by the circulating cleaning fluid. Measuring the electrical conductivity of this cleaning solution,
Find the accumulated equivalent salt adhesion amount.

[Problem to be solved by the invention] The problem with the conventional technology is (1) the brush washing method.

(2) Dew point method for measuring the amount of contamination and C3) Ultrasonic cleaning method for measuring the amount of contamination are both currently in use for insulators and materials.

It is necessary to separately prepare a pilot insulator with the same shape and install it under the same conditions as the insulator in operation, and if the insulator is installed at a high place or at multiple points, it will take a lot of effort and time to make measurements. It was uneconomical. In addition, in the spherical simulated hook method (4), there is inevitably a difference in adhesion between the spherical simulated insulator and the actual insulator, so this needs to be corrected, which takes time and effort to determine the amount of contamination. .

Next, considering each method in terms of accuracy, the brush washing method (1) requires skill and time for measurement.

The dew point method for measuring the amount of contamination (2) requires a calibration device to convert the wetting resistance into the equivalent amount of salt deposited, and this needs to be created for each measurement location.

In (3), the ultrasonic cleaning method for measuring the amount of contamination, the insulator is updated each time the measurement is performed, so there is a problem with how to estimate the amount of contamination on the insulator during actual operation, which depends on the exposure period. In the spherical model N'iR child method of (4), there is nothing that can be done,
There were drawbacks such as the rain-washing effect caused by rainfall which easily caused errors in the integrated value.

Under these circumstances, it is necessary to develop more advanced measurement methods, such as measuring the amount of contaminants adhering to insulators during actual operation in real time rather than periodically, or measuring the distribution of contaminants on the surface of insulators. It was wanted.

For this reason, as method (5), an optical waveguide that causes optical loss when salt adheres to the surface is exposed and mounted on the insulator surface.
There is a method for measuring a tolerable amount of contamination in which transmitted light is received from one end of the optical waveguide and exits from the other end, and the amount of salt adhering to the insulator is determined from a change in the intensity of the transmitted light.

This method (5) is an excellent method that suits the purpose, but
Even when substances other than salt, such as dust in the air, adhere to the surface of the optical waveguide, optical loss occurs, and as a result, there is a risk that salt adhesion may be overestimated.

Taking a closer look at this point, dust floating in the air generally contains silicon dioxide (SiO2) as a main component, as well as calcium sulfate (CaSOa H2H2).
0>, Kaolinite (AJ 2 S tos (OH
) 4) etc. are included.

In addition to salt (Nacj), powder is commonly used to simulate artificial dust in glass staining tests, and its main component is kaolinite. When using pure quartz (refractive index -1.46), when silicon dioxide (refractive index -1.46) adheres to the surface of the pure quartz, the light that travels inside the quartz will be reflected once at the place of attachment. Although it passes into the interior, it is reflected at the interface between silicon dioxide and air and returns to the interior of the quartz, so its effect can be almost ignored, whereas calcium sulfate (refractive index = 1.58) and kaolin When night (refractive index = 1.56) adheres, salt (refractive index -1,
Optical loss occurs due to the same principle as 54).

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art and to provide a novel device that can detect only salt among the contaminants adhering to an insulator and measure the density of salt adhesion.

[Means for Solving the Problems] The salt adhesion density detecting device of the present invention includes a first leading wavepath having a refractive index value smaller than that of NaCj';
greater than the refractive index value of Cl and AJ 2 SiOs
(OH) The detection unit has a second waveguide having a refractive index value smaller than the refractive index of 4, and transmits transmitted light that is input from one end of the first and second optical waveguides and exits from the other end. The light is received by each optical waveguide, and the amount of salt per unit area adhering to the detection portion is determined from the difference in the amount of change in transmitted light intensity generated from the first and second optical waveguides.

[Operation] The first optical waveguide is for detecting contaminants such as salt and dust (calcium sulfate, kaolinite, etc.), and the second optical waveguide is for detecting the dust. If there is no contaminant attached to the leading waveguide, there is air around the optical waveguide, so the propagating light does not suffer any loss.

Now, assume that a mixture of salt and dust has adhered to the first and second optical waveguides.

Since the first optical waveguide has a smaller refractive index than salt and dust, optical loss occurs due to salt and dust. On the other hand, in the second optical waveguide, since its refractive index is greater than that of salt and smaller than that of dust, optical loss due to dust occurs but no optical loss due to salt occurs.

Therefore, by determining the difference between the amount of change in the intensity of transmitted light generated from the first optical waveguide and the amount of change in the intensity of transmitted light generated from the second optical waveguide, it is possible to determine the amount of adhesion (salt adhesion) only related to salt adhering to the detection part. Density) can be found.

[Example] Hereinafter, the present invention will be explained based on illustrated embodiments.

Figure 1 shows the configuration of the salt adhesion density detection device.

This device includes a light source section 1. Optical splitter 2. Detection unit 3. Light receiving section 4
．． Arithmetic unit 5. It is composed of an optical fiber 6 and a signal cable 7.

The detection section 3 consists of two optical waveguides 3a and 3b.

The first optical waveguide 3a is a leading waveguide having a refractive index value smaller than the refractive index value of NaCl, which is 1.54, and in this embodiment is made of a quartz rod made of pure quartz (refractive index 1.46). Ru. The second optical waveguide 3b has a refractive index value of AJ 2 S i Os (OH) 4 greater than 1.
It is an optical waveguide having a refractive index value smaller than 56, and in this embodiment, it is composed of a quartz rod using quartz crystal (refractive index 1.55).

Light emitted from the light source section 1 is guided to the optical splitter 2 via the optical fiber 6, and is split into two by the optical splitter 2. It is possible to consider a configuration that does not use the optical splitter 2, but in that case, not only would it be necessary to add the light source unit 1, but it would also be necessary to perform temperature correction for the optical output, making it impractical in terms of cost. Each of the detected lights reaches the detection unit 3 via the optical fiber 6, and the first . Second optical waveguide 3a, 3b
guided by. The light that has experienced optical loss changes due to the adhesion of salt and dust in the detection unit 3 is guided to the light receivers 4a and 4b that constitute the light receiving unit 4 via the optical fiber 6, respectively, and is changed depending on the intensity of the transmitted light. converted into electrical output.

Incidentally, the detection section 3 has the first. second optical waveguide, 3a+
The input end side and the output end side of 3b are connected to optical fibers 6, respectively.
Since the light source unit 1. is connected to the light source unit 1. Light receiving section 4. The calculation unit 5 can be isolated from this strong electromagnetic field to safely perform measurements.

The arithmetic unit 5 connects the light receiver 4a to the light receiver 4a through the signal gaple 7.7.
+ 4 The amount of change in transmitted light intensity obtained from b (that is, the transmitted light intensity based on the case where there is no adhesion on the detection part 3)
Based on this, the amount of salt only (salt adhesion density) is calculated from the relational expression between the amount of transmitted light intensity change known in advance for the optical waveguides 3a and 3b and the amount of contaminant adhesion per unit area. In this embodiment, the salt adhesion amount is calculated by calculating the difference between the amount of contaminant adhesion per unit area determined by the light receiver 4a and the amount of contaminant adhesion per unit area determined by the light receiving section 4b. Depends on processing.

Let me explain in detail.

First, NaCl and AJ2SiOs(OH)
The amount of change in transmitted light intensity determined from the light intensity detected by the light receiving part 4 and the sample plate placed near the detecting part 3 are determined by the amount of change in transmitted light intensity determined from the light intensity detected by the light receiving part 4. The relationship between the amount of contaminants adhering to (single area plate) (the weight of contaminants divided by the sample area) was investigated. The results of this experiment are shown in FIG. FIG. 2(a) shows the relationship between the amount of change in transmitted light intensity □ and the amount of contaminants attached in the first optical waveguide 3a made of a quartz rod, and FIG.
3b shows the relationship between the amount of change in transmitted light intensity and the amount of contaminants attached Next, we tried changing the above mixing ratio of contaminants, but the light source 1 used this time was a laser diode with a wavelength of 0.85 μm. In the case of LEDs, even when the mixing ratio of contaminants is changed, the relationship between the amount of change in transmitted light intensity and the amount of contaminants is
It is almost the same as the figure.

The function of detecting only salinity under the above-mentioned pre-trapping will be explained. As already mentioned, the first optical waveguide 3a includes a quartz rod (refractive index 1.46), and the second leading waveguide 3b includes a quartz rod (refractive index: 1.46).
It is assumed that a refractive index of 1.55> is used.

Now, in the detection unit 3, the salt content NaCj' (refractive index value 1.54)
Also, kaolinite Aj2SiO is present as dust.

Consider the case where (OH) is mixed and deposited. Here, considering kaolinite Aj2stos (OH) (refractive index 1.56) as dust is equivalent to considering calcium sulfate (refractive index 1.58), which has a larger trend index value. .

When light enters the quartz rod (3a) and the quartz rod (3b) from one end of each, the propagating light is almost lost because there is air around both rods in the absence of contaminants as described above. Without reaching the other end of the quartz rod and the crystal rod. However, if kaolinite adheres to the detection part 3e along with the above salt, the quartz rod (3a), which has a refractive index smaller than NaCl and Aj2Sin, (OH)4, will cause optical loss due to the adhered salt and kaolinite. . On the other hand, NaCl
Greater AJ x Si Os (OH)-
In the quartz crystal rod (3b) having a smaller refractive index, light loss occurs due to kaolinite, but no light loss occurs due to salt.

In short, the transmitted light intensity obtained from the quartz rod (3a) includes the influence of optical loss due to both salt and dust, but the transmitted light intensity obtained from the quartz rod (3b) includes the influence of optical loss due to dust. Receivers 4a and 4b that only include effects
converts these into electrical output.

The calculation unit 5 first converts the amount of change in the transmitted light intensity, which is the electrical output, into the amount of contaminant adhesion per unit area using the relational expressions representing the characteristic curves shown in FIGS. 2(a) and 2(b). As is already clear, the amount of contaminant adhesion determined from the characteristic curve of FIG. 2(a) is
It is a mixture of s (OH) 4, and is shown in Figure 2 (b).
) The amount of contaminant adhesion determined from the characteristic curve of AJ
2S i Os (OH)-.

Next, the calculation unit 5 calculates the Na
The difference between the amount of contaminants attached to the mixture of Cl and Aj 2sios (OH) and the amount of contaminants attached to AN 2 S i Os '(OH) 4 is determined. In this way, the amount of NaCl attached per unit area is determined.

Next, a specific example of the configuration of the detection section 3 will be shown.

The optical waveguides 3a and 3b are basically (1) mounted exposed on a thin film, (2) installed by adhering to the surface of the insulator, or (3) installed with a jig installed on the surface of the insulator. It can be configured to be fixed.

FIG. 3 shows an embodiment in which both ends of rod-shaped optical waveguides 3a and 3b are fixed with an L-shaped stand-shaped jig 8. The detection unit 3 can be directly bonded to the measurement surface (for example, the surface of an insulator) without using such a stand-type jig 8, but in this case, the adhesive should have a refractive index value that is Optical waveguide (having a refractive index value smaller than that of NaC)
A smaller one is preferable.

FIG. 4(a) shows an example of a configuration in which the optical waveguides 3a and 3b are circular and installed in circular grooves 10 of the folds on the lower surface of the insulator 9, and the amount of salt in the folds is determined.

In order to maintain the mechanical strength of the detection unit 3, the optical waveguides 3a, 3
It is preferable that the periphery of b is fixedly supported by a ring-shaped jig 81.

FIG. 4(b) shows an optical waveguide 3a in which a substrate 11 is installed on the lower surface of the glass 9, a detection unit 3 is installed on this substrate, and the amount of salt adhering to the entire lower surface is determined.

The measurement range can be expanded by changing the length of the optical waveguides 3a and 3b, as shown in FIG.
If they are made concentric, II determination can be performed without being affected by the installation position of the detection unit 3.

In this case as well, in order to maintain the mechanical strength of the detection section 3, it is preferable that the optical waveguides 3a, 3b are fixedly supported around the circumference by a ring-shaped jig 82.

In both of the configuration examples shown in FIG. 3 and FIG. etc.) is desirable.

[Effects of the Invention] As described above, according to the present invention, the following excellent effects are exhibited. ＼ (1) Among the contaminating substances adhering to the insulator surface, only the amount of salt can be determined separately, excluding the dust component of the shell.

(2) Measurements can be made in a high electromagnetic field environment.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram showing an embodiment of the salt adhesion density detecting device of the present invention, Fig. 2 is a diagram showing the relationship between the amount of change in transmitted light loss of the detection part and the amount of contaminant adhesion obtained by experiment. FIG. 3 is a schematic diagram showing a specific example of the configuration of the detection section, and FIG. 4 is a schematic diagram showing another example of the configuration of the detection section. In the figure, 1 is a light source section, 2 is an optical splitter, 3 is a detection section, 3a is a first optical waveguide, 3b is a second optical waveguide, 4 is a light receiving section,
4a, 4b are light receivers, 5 is a calculation unit, 6 is an optical fiber, 7
is a signal cable, 8.81°82 is a jig, 9 is an insulator, 1
0 indicates clear and 11 indicates substrate. Patent applicant: Hitachi Cable Co., Ltd. Representative Patent Attorney Nobuo Kinutani (a) (b) Figure 2

Claims (1)

[Claims] 1. A first optical waveguide having a refractive index value smaller than the refractive index value of NaCl, and a first optical waveguide having a refractive index value larger than the refractive index value of NaCl;
The detection unit has a second waveguide having a refractive index value smaller than the refractive index of l_2SiO_5(OH)_4, and transmitted light enters from one end of the first and second optical waveguides and exits from the other end. A salt adhesion density detecting device, characterized in that the salt adhesion density detecting device receives each light and determines the amount of salt per unit area of the salt adhering to the detection part from the difference in the amount of change in transmitted light intensity generated from the first and second optical waveguides. .