CN114371398A - Partial discharge optical sensor external system and method based on one-to-many optical fibers - Google Patents

Abstract

The application discloses an external system and a method of a partial discharge optical sensor based on one-to-many optical fibers, which comprises the following steps: the front-end optical fiber probe is provided with a multi-core optical fiber and collects discharge beams of partial discharge in the gas insulated switchgear; the optical splitter equally divides the multi-core optical fiber into a plurality of groups of multi-core optical fibers so as to evenly divide the discharge light beam into a plurality of groups of light beams; the transmission light path module encapsulates a plurality of groups of sub-multi-core optical fibers equally divided by the optical splitter into a plurality of groups of transmission light paths, and the plurality of groups of transmission light paths respectively transmit a plurality of groups of light beams evenly divided by the discharge light beams; filtering out the light beam with the specific spectral band by the filter coating film to obtain a multispectral signal; the optical sensor converts the multispectral signal into a photocurrent signal. The invention realizes the external arrangement of the partial discharge optical sensor aiming at the gas insulated switchgear, avoids the influence of high air pressure and high field intensity environment inside the GIS equipment on the working performance of the optical sensor, and simultaneously avoids the reduction of the GIS equipment insulation performance caused by the arrangement of the sensors.

Description

A partial discharge optical sensor external system and method based on one-point multi-fiber

technical field

The invention belongs to the technical field of electric equipment detection, and relates to a partial discharge optical sensor external system and method based on one-point multi-fiber.

Background technique

Gas Insulated Switchgear (GIS, Gas lnsulated Switchgear) seals the main equipment in the substation such as isolating switches, circuit breakers, earthing switches, transformers, arresters and busbars in a metal shell, and fills the shell with high-pressure gas. Sulfur hexafluoride gas realizes gas-insulated switchgear, which has the advantages of good insulation performance, small footprint, low maintenance cost, and strong environmental adaptability, and is currently widely used in power systems.

However, during assembly, transportation or long-term operation of GIS equipment, it is inevitable that there will be faults and defects and the occurrence of partial discharge. Long-term partial discharge will damage the insulation performance of the equipment, shorten the life of the equipment, and even lead to electrical accidents. Therefore, the partial discharge monitoring of GIS equipment can avoid the occurrence of serious accidents and maintain the safe and stable operation of the power system.

At present, four mainstream monitoring methods have been derived for the accompanying phenomenon of partial discharge in GIS equipment, namely pulse current method, ultra-high frequency method, ultrasonic method and optical measurement method. Among them, the optical measurement method has been gradually applied and promoted in the partial discharge monitoring of power equipment because of its strong anti-interference ability and the advantages of reflecting the essential characteristics of partial discharge.

In photometry, there are three main types of analysis methods for photoelectric signals. One is the direct method, which directly analyzes the amplitude and peak time characteristics of the photocurrent signal, and uses the photocurrent amplitude to correspond to the relative intensity of partial discharge light radiation; The sensor performance is affected, so this method is often used in the qualitative analysis of partial discharge optical signals. Another method is the photocurrent signal statistical feature analysis method, which is similar to the traditional monitoring method. This method superimposes the photocurrent signals collected over a period of time to generate a PRPD spectrum according to the device voltage information, and performs statistical feature analysis on it. Extraction and analysis, the results can be used for partial discharge fault type judgment and severity analysis; but this method must be analyzed based on the voltage phase signal, so it cannot be applied when the voltage phase or DC equipment cannot be obtained, so it is difficult to promote in actual power equipment . The three-spectroscopy method is an emerging photocurrent analysis method. This method collects the partial discharge optical signals in the ultraviolet, visible, and near-infrared bands and the photocurrent signals output by the corresponding sensors, and analyzes the photocurrent in the three bands. The signal is analyzed by optical pulse intensity, intensity ratio and statistical feature quantity, which can realize the degree of partial discharge type analysis; this method gets rid of the voltage phase dependence of the traditional statistical analysis method, and by analyzing the spectral information, it increases the sensitivity of the optical signal. Utilization rate, and can quantitatively analyze the partial discharge signal of power equipment, which further promotes the popularization of optical measurement method in actual power equipment.

However, although the photometric method has great advantages over other partial discharge detection methods, and there are miniature sensitive optical sensors that can be applied to partial discharge detection of individual power equipment, it is difficult to popularize and apply in GIS equipment. The reason is that the interior of the GIS equipment shell is filled with sulfur hexafluoride gas, forming a high-pressure environment, and the existing partial discharge optical sensors cannot withstand the standard pressure level of GIS equipment; in addition, due to the compact structure of GIS equipment, During its normal operation, a high field strength environment will be formed in the space, which may affect the normal operation of the partial discharge optical sensor, and the built-in sensor may affect the distribution of the electric field of the GIS equipment, resulting in the decline of the insulation performance.

Therefore, in order to meet the requirements of partial discharge optical sensors for location detection and multi-spectral signal acquisition in GIS equipment, a new arrangement of external optical sensors for gas-insulated switchgear is urgently needed.

SUMMARY OF THE INVENTION

In order to solve the deficiencies in the prior art, the present application provides a partial discharge optical sensor external system and method based on one-point multi-fiber, the front-end optical fiber probe is installed in the gas-insulated switchgear to collect partial discharge optical signals, The multi-core optical fiber in the front-end fiber probe is divided into multiple groups of multi-core optical fibers by the optical splitter, and multiple transmission optical paths are drawn out. Each transmission optical path is processed by the filter coating of different wavelength bands at the back end and connected to the optical sensor, and finally realizes gas insulation. External placement of partial discharge optical sensors in switchgear and acquisition of multispectral signals.

In order to achieve the above goals, the present invention adopts the following technical solutions:

A partial discharge optical sensor external system based on one-point multi-fiber, comprising:

Front-end fiber optic probe, which is equipped with multi-core fiber, used for the collection and extraction of the discharge beam of partial discharge in gas-insulated switchgear;

an optical splitter, which is connected to the front-end fiber probe, and is used for dividing the multi-core optical fibers into multiple groups of multi-core optical fibers so as to divide the discharge beam into multiple groups of beams evenly;

A transmission optical path module, which is connected to the optical splitter, and is used to encapsulate multiple groups of sub-multi-core optical fibers equally divided by the optical splitter into multiple groups of transmission optical paths, and the multiple groups of transmission optical paths respectively transmit multiple groups of uniformly divided discharge beams. beam;

filter coating, which is arranged at the output ends of the multiple groups of transmission optical paths, and is used to filter out the beams of specific spectral bands to obtain multi-spectral signals;

An optical sensor with multiple independent signal channels connected to a filter coating for converting multispectral signals into photocurrent signals.

The present invention further includes the following preferred solutions:

Preferably, the front-end fiber optic probe is installed in the casing of the gas-insulated switchgear through a prefabricated opening or a prefabricated flange.

Preferably, the outer layer of the front-end fiber optic probe is provided with a shell to ensure the firmness of the front-end fiber optic probe, and the shell is equipped with a sealing ring to ensure the air-tightness of the gas-insulated switchgear after the front-end fiber optic probe is installed.

Preferably, the multi-core optical fiber configured by the front-end fiber optic probe is provided with a separate cladding, and the plane of the multi-core optical fiber matches the front end of the housing.

Preferably, the front end of the optical splitter is matched with the casing of the optical fiber probe, and the rear end of the optical splitter is matched with multiple groups of transmission optical paths of the transmission optical path module.

Preferably, in the transmission optical path module, each group of multi-core optical fibers is packaged with a separate cladding and then an outer sheath is provided on the outermost layer.

Preferably, the wavelength coverage of the filter coating is 300 nm to 750 nm and the transmittance is not lower than 90%.

Preferably, the multiple independent signal channels of the optical sensor correspond to the multiple groups of transmission optical paths in one-to-one correspondence to realize synchronous acquisition of multi-spectral signals.

Preferably, the optical sensor is a silicon photomultiplier linear array.

Preferably, the spectral response coverage of the silicon photomultiplier linear array is 300 nm to 750 nm, the single-photon detection efficiency is not lower than 90%, and the gain is not lower than 10 ⁶ .

The present invention also provides a partial discharge optical sensor external method based on one-point multi-fiber, including:

Step 1: The front-end fiber optic probe is installed in the gas-insulated switchgear through prefabricated openings or prefabricated flanges, and its airtightness is maintained by a sealing ring;

Step 2: The front end of the optical fiber probe is connected to the optical splitter, and the partial discharge beam generated by the partial discharge inside the gas-insulated switchgear is led out to the optical splitter by the front optical fiber probe;

Step 3: The beam splitter divides the partial discharge beam into multiple groups of beams and exports the partial discharge beam through multiple groups of transmission optical paths;

Step 4: by setting filter coatings of different wavelength bands at the output ends of different transmission optical paths respectively, so that only the optical signal of the corresponding wavelength band is allowed to be output by a single said transmission optical path;

Step 5: The optical signal of the transmission optical path is filtered by the filter coating and transmitted to the optical sensor;

Step 6: The multiple groups of signal channels of the optical sensor correspond one-to-one with the multiple groups of transmission optical paths, and the optical sensor processes the optical signals and outputs photocurrent signals, so as to realize the external placement of the optical sensor and the acquisition of multi-spectral signals.

The beneficial effects achieved by this application:

The invention realizes the external installation of the partial discharge optical sensor for gas-insulated switchgear, and extracts the partial discharge multi-path optical signal through the front-end optical fiber probe, the optical splitter and the transmission optical path, which is different from the traditional optical fiber probe. The synchronous export of road optical signals provides conditions for the acquisition of subsequent multi-spectral signals. In addition, the installation design considers the air tightness of the fiber probe in the high pressure environment of GIS, and considers the aging characteristics of the fiber probe in the high voltage environment. As well as insulation compatibility, it avoids air leakage and insulation performance degradation of GIS equipment caused by the built-in probe, and realizes the simultaneous output of multiple optical signals while maintaining the safe and stable operation of GIS equipment.

On the basis of the external optical sensor, the present invention further realizes the collection of partial discharge multi-spectral data, and performs filter coating processing of different wavelength bands on different transmission optical paths, so that a single transmission optical path only allows the optical signal of the corresponding wavelength band Output, realizes the further improvement of the one-point multi-fiber, which is different from the all-optical signal output of the traditional fiber. The improved one-point multi-fiber realizes the output of multi-spectral signals, and combines multiple transmission optical paths with multiple independent optical sensors. The acquisition channels are in one-to-one correspondence, and finally the acquisition of multi-spectral data is realized, which increases the utilization rate of the partial discharge optical signal.

Description of drawings

Fig. 1 is the system structure schematic diagram of the present invention;

Fig. 2 is the system structure block diagram of the present invention;

3 is a schematic diagram of a front-end optical fiber probe of the present invention;

4 is a schematic diagram of a transmission optical path module of the present invention;

5 is a schematic diagram of the internal structure of the optical splitter of the present invention;

Fig. 6 is the front-end optical fiber probe installation schematic diagram of the present invention;

The reference numerals are: 1- front-end fiber probe, 2- optical splitter, 3- transmission optical path, 4- filter coating, 5- optical sensor, 6- multi-core fiber, 7- cladding, 8- shell, 9- each Group of multi-core fibers, 10-individual cladding, 11-outer sheath, 12-sealing ring, 13-flange.

Detailed ways

The present application will be further described below with reference to the accompanying drawings. The following examples are only used to more clearly illustrate the technical solutions of the present invention, and cannot be used to limit the protection scope of the present application.

As shown in Figures 1 and 2, a partial discharge optical sensor external system based on one-point multi-fiber of the present invention includes:

The front-end fiber probe 1, which is equipped with a multi-core fiber 6, is used for the collection and extraction of the discharge beam of the partial discharge in the gas-insulated switchgear;

During specific implementation, the front-end fiber optic probe 1 is installed in the casing of the gas-insulated switchgear through a prefabricated opening or a prefabricated flange 13 .

The outer layer of the front-end fiber optic probe 1 is provided with a casing 8 to ensure the firmness of the front-end fiber optic probe 1, and the casing 8 is equipped with a sealing ring 12 to ensure the air-tightness of the gas-insulated switchgear after the front-end fiber optic probe 1 is installed.

The multi-core fiber 6 configured in the front-end fiber probe 1 is provided with a separate cladding 7, and the plane of the multi-core fiber 6 is matched with the front end of the housing 8, as shown in FIG. 3 .

The optical splitter 2, which is connected to the front-end fiber probe 1, is used to divide the multi-core optical fiber 6 into multiple groups of multi-core optical fibers to evenly divide the discharge beam into multiple groups of beams, as shown in Figure 5;

The front end of the optical splitter 2 is matched with the casing 8 of the front end fiber probe 1, and the rear end of the optical splitter 2 is matched with the multiple groups of transmission optical paths 3 of the transmission optical path module.

A transmission optical path module, which is connected to the optical splitter 2, and is used to encapsulate the multiple groups of sub-multi-core fibers equally divided by the optical splitter 2 into multiple groups of transmission optical paths 3, and the multiple groups of transmission optical paths 3 transmit the discharge beams and evenly divide them multiple sets of beams;

In the transmission optical path module, each group of multi-core optical fibers 9 is packaged with a separate cladding 10 and an outer sheath 11 is provided on the outermost layer, as shown in FIG. 4 .

filter coating 4, which is arranged at the output ends of the multiple groups of transmission optical paths 3, and is used to filter out the light beams of a specific spectral band to obtain multi-spectral signals;

By disposing different wavelength band filter coatings 4 on different transmission optical paths 3 respectively, a single said transmission optical path 3 only allows the output of optical signals of corresponding wavelength bands.

The filter wavelength range of the filter coating 4 includes ultraviolet to near-infrared wavelengths.

The wavelength coverage of the filter coating 4 is 300nm to 750nm and the transmittance is not less than 90%.

The optical sensor 5 has a plurality of independent signal channels and is connected to the filter coating 4 for converting the multispectral signal into a photocurrent signal.

The sizes of the multiple independent signal channels of the optical sensor 5 are in one-to-one correspondence with the multiple groups of transmission optical paths 3 to realize synchronous acquisition of multi-spectral signals.

The optical sensor 5 performs independent and synchronous acquisition of optical signals on the multiplex transmission optical paths.

The optical sensor 5 is a silicon photomultiplier linear array, the spectral response coverage of the silicon photomultiplier linear array is 300 nm to 750 nm, the single photon detection efficiency is not lower than 90%, and the gain is not lower than 10 ⁶ .

A one-point multi-fiber partial discharge optical sensor external method of the present invention includes:

Step 1: The front-end fiber optic probe 1 is installed in the gas-insulated switchgear through prefabricated openings or prefabricated flanges 13, and the outer casing 8 of the front-end fiber optic probe 1 and the flange 13 are kept airtight by the sealing ring 12. The installation diagram is shown in Figure 6 shown.

Step 2: The rear end of the front-end fiber probe 1 is connected to the optical splitter 2, and the partial discharge beam generated by the partial discharge inside the gas-insulated switchgear is led out by the front-end optical fiber probe 1 to the optical splitter 2;

Step 3: The beam splitter 2 divides the partial discharge beam into multiple groups of beams and exports the partial discharge beam through multiple groups of transmission optical paths 3;

Step 4: by setting the filter coatings 4 of different wavelength bands at the output ends of different transmission optical paths 3 respectively, so that the single transmission optical path 33 only allows the output of optical signals of the corresponding wavelength band;

Step 5: The optical signal of the transmission optical path 3 is filtered by the filter coating 4 and then transmitted to the optical sensor 5;

Step 6: The multiple groups of signal channels of the optical sensor 5 correspond to the multiple groups of transmission optical paths 3 one-to-one. The optical sensor 5 processes the optical signals and outputs photocurrent signals to realize the external placement of the optical sensor 5 and the acquisition of multi-spectral signals.

The invention realizes the external installation of the partial discharge optical sensor for the gas-insulated switchgear, and extracts the partial discharge multi-channel optical signal through the front-end fiber probe, the optical splitter and the transmission optical path, so as to avoid the high pressure and high field intensity inside the GIS equipment. The influence of the optical sensor's working performance also avoids the degradation of the insulation performance of the GIS equipment caused by the sensor arrangement.

On the basis of the external optical sensor, the present invention further realizes the collection of partial discharge multi-spectral data, and performs filter coating processing of different wavelength bands on different transmission optical paths, so that a single transmission optical path only allows the optical signal of the corresponding wavelength band output, and one-to-one correspondence between multiple transmission optical paths and multiple independent acquisition channels on the optical sensor, and finally realizes the acquisition of multi-spectral data, which increases the utilization rate of partial discharge optical signals.

The applicant of the present invention has described and described the embodiments of the present invention in detail with reference to the accompanying drawings, but those skilled in the art should understand that the above embodiments are only preferred embodiments of the present invention, and the detailed description is only to help readers better It should be understood that the spirit of the present invention is not limited to the protection scope of the present invention. On the contrary, any improvement or modification made based on the spirit of the present invention should fall within the protection scope of the present invention.

Claims (11)

1. a partial discharge optical sensor external system based on one point of multi-fiber, is characterized in that: The system includes: Front-end fiber optic probe, which is equipped with multi-core fiber, used for the collection and extraction of the discharge beam of partial discharge in gas-insulated switchgear; an optical splitter, which is connected to the front-end fiber probe, and is used for dividing the multi-core optical fibers into multiple groups of multi-core optical fibers so as to divide the discharge beam into multiple groups of beams evenly; A transmission optical path module, which is connected to the optical splitter, and is used to encapsulate multiple groups of sub-multi-core optical fibers equally divided by the optical splitter into multiple groups of transmission optical paths, and the multiple groups of transmission optical paths respectively transmit multiple groups of uniformly divided discharge beams. beam; filter coating, which is arranged at the output ends of the multiple groups of transmission optical paths, and is used to filter out the beams of specific spectral bands to obtain multi-spectral signals; An optical sensor with multiple independent signal channels connected to a filter coating for converting multispectral signals into photocurrent signals. 2. a kind of partial discharge optical sensor external system based on one-point multi-fiber according to claim 1, is characterized in that: The front-end fiber optic probe is installed in the casing of the gas-insulated switchgear through prefabricated openings or prefabricated flanges. 3. a kind of partial discharge optical sensor external system based on one-point multi-fiber according to claim 2, is characterized in that: The outer layer of the front-end optical fiber probe is provided with a casing to ensure the firmness of the front-end optical fiber probe, and the casing is equipped with a sealing ring to ensure the air-tightness of the gas-insulated switchgear after the front-end optical fiber probe is installed. 4. a kind of partial discharge optical sensor external system based on one-point multi-fiber according to claim 3, is characterized in that: The multi-core optical fiber configured by the front-end fiber probe is provided with a separate cladding, and the plane of the multi-core optical fiber matches the front end of the housing. 5. a kind of partial discharge optical sensor external system based on one-point multi-fiber according to claim 3, is characterized in that: The front end of the optical splitter is matched with the casing of the optical fiber probe, and the rear end of the optical splitter is matched with multiple groups of transmission optical paths of the transmission optical path module. 6. A kind of partial discharge optical sensor external system based on one-point multi-fiber according to claim 1, is characterized in that: In the transmission optical path module, each group of multi-core optical fibers is encapsulated with a separate cladding and then an outer sheath is arranged on the outermost layer. 7. A kind of partial discharge optical sensor external system based on one-point multi-fiber according to claim 1, is characterized in that: The wavelength coverage of the filter coating is 300nm to 750nm and the transmittance is not less than 90%. 8. A kind of partial discharge optical sensor external system based on one-point multi-fiber according to claim 1, is characterized in that: The multiple independent signal channels of the optical sensor are in one-to-one correspondence with the multiple groups of transmission optical paths to achieve synchronous acquisition of multi-spectral signals. 9. A kind of partial discharge optical sensor external system based on one-point multi-fiber according to claim 1, is characterized in that: The optical sensor is a silicon photomultiplier linear array. 10. A partial discharge optical sensor external system based on one-point multi-fiber according to claim 9, characterized in that: The spectral response coverage of the silicon photomultiplier linear array is 300 nm to 750 nm, the single-photon detection efficiency is not less than 90%, and the gain is not less than 10 ⁶ . 11. An external method for a partial discharge optical sensor based on a one-point multi-fiber using the one-point multi-fiber-based partial discharge optical sensor external system according to any one of claims 1-10, characterized in that: The method includes: Step 1: The front-end fiber optic probe is installed in the gas-insulated switchgear through prefabricated openings or prefabricated flanges, and its airtightness is maintained by a sealing ring; Step 2: The front end of the optical fiber probe is connected to the optical splitter, and the partial discharge beam generated by the partial discharge inside the gas-insulated switchgear is led out to the optical splitter by the front optical fiber probe; Step 3: The beam splitter divides the partial discharge beam into multiple groups of beams and exports the partial discharge beam through multiple groups of transmission optical paths; Step 4: by setting filter coatings of different wavelength bands at the output ends of different transmission optical paths respectively, so that a single said transmission optical path only allows the output of optical signals of the corresponding wavelength band; Step 5: The optical signal of the transmission optical path is filtered by the filter coating and transmitted to the optical sensor; Step 6: The multiple groups of signal channels of the optical sensor correspond one-to-one with the multiple groups of transmission optical paths, and the optical sensor processes the optical signals and outputs photocurrent signals, so as to realize the external placement of the optical sensor and the acquisition of multi-spectral signals.

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