CN215677198U - Automatic detection device for insulation oil holding quantity of oil immersed transformer - Google Patents
Automatic detection device for insulation oil holding quantity of oil immersed transformer Download PDFInfo
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- CN215677198U CN215677198U CN202121862443.3U CN202121862443U CN215677198U CN 215677198 U CN215677198 U CN 215677198U CN 202121862443 U CN202121862443 U CN 202121862443U CN 215677198 U CN215677198 U CN 215677198U
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Abstract
The utility model belongs to the field of insulation and cooling of oil immersed transformers, and particularly relates to an automatic detection device for the insulation oil holding capacity of an oil immersed transformer. The utility model can realize the automatic detection of the insulating oil holding amount of the oil immersed transformer, and the monitoring center can know the dynamic change condition of the insulating oil holding amount in the oil immersed transformer on line in real time.
Description
Technical Field
The utility model belongs to the field of insulation and cooling of oil immersed transformers, and particularly relates to an automatic detection device for insulation oil holding amount of an oil immersed transformer.
Background
The transformers are classified according to cooling modes and can be classified into three categories, namely evaporation cooling transformers, oil immersed (self-cooling) transformers and dry-type (self-cooling) transformers, and the oil immersed transformers are widely applied to ultrahigh-voltage and extra-high-voltage transmission and transformation systems. The quality of the insulating oil as an important insulating material in the transformer and the profit and loss of the quality of the insulating oil are directly related to the insulating electrical life of the transformer. During the use and maintenance of the transformer, most of the damage is often caused by the damaged insulation; therefore, improving the quality of the insulating oil and ensuring a reasonable amount of insulating oil will be key factors in improving the level and quality of the transformer product. The simple measurement of the insulating oil retention in the oil-immersed transformer adopts a probe measurement method, a probe is vertically inserted into the transformer, and the probe is taken out to judge the quantity of the insulating oil in the transformer through a grease infiltration line. The method is easy to cause the pollution of the transformer insulating oil due to the opening of the oil tank cover of the transformer and the insertion and the extraction of the probe; and the oil-immersed line of the probe is used for judging the holding amount of the insulating oil in the transformer, which is only a rough estimation and cannot realize accurate measurement. There is also a method for detecting the amount of the insulating oil in the transformer by adopting an electric sensor, but the method is limited because the related physical parameters in the oil are detected by passing current and voltage, which easily brings about potential safety hazard.
Disclosure of Invention
The utility model aims to provide an automatic detection device for the oil-immersed transformer insulating oil holding capacity, which realizes remote real-time online detection of the transformer oil holding capacity.
The purpose of the utility model is realized by the following technical scheme:
the automatic detection device for the insulating oil holding quantity of the oil immersed transformer is characterized by comprising a plurality of measuring probes embedded in the oil immersed transformer, a shunt connected with the plurality of measuring probes, a filtering and demodulating device connected with the shunt, a data processor connected with the filtering and demodulating device, a computer connected with the data processor, a monitoring center connected with the computer,
each measuring probe comprises an outer cover, an oil seepage hole and an oil seepage net which are arranged at the bottom of the outer cover, an elastic diaphragm arranged in the outer cover, an optical fiber pressure sensor arranged in the outer cover and attached to the elastic diaphragm, an optical fiber arranged in the optical fiber pressure sensor, an optical fiber fastening mechanism connected with the optical fiber pressure sensor and an optical fiber protection connector.
The splitter is connected with the plurality of measuring probes through optical fibers, and distributed arrangement of the optical fiber pressure sensors is achieved.
The filtering and demodulating device comprises a light source, a signal filter and a signal demodulator.
The optical fiber is a single mode optical fiber, and the wavelength range is as follows: 1530-1570 nm; the wavelength resolution is: 1 pm; and (3) drift calibration: 10 pm; loss: 12 dB; scanning frequency: 50 HZ.
The utility model has the advantages that:
(1) the automatic detection device for the insulating oil retention of the oil immersed transformer can realize the automatic detection of the insulating oil retention of the oil immersed transformer, and a monitoring center can know the dynamic change condition of the insulating oil retention in the oil immersed transformer on line in real time; the change condition of the insulating oil liquid level in the oil-immersed transformer can be well recorded, and early warning information of the insulating oil holding amount can be given by combining the design parameters of the oil-immersed transformer, so that the method has very important significance on the safe operation of the oil-immersed transformer;
(2) compared with the traditional electric sensor, the automatic detection device for the insulating oil holding quantity of the oil immersed transformer has the advantages that the measurement signal is an optical signal transmitted out of an optical fiber, and no current or voltage is loaded on a sensor immersed in oil, so that the device is flame-proof and explosion-proof, and is absolutely safe in physical sense;
(3) the automatic detection device for the insulating oil holding amount of the oil immersed transformer has the advantages that the measuring probe is simple in structure, small in size, light in weight and variable in shape, and is particularly suitable for being embedded into large structures such as the oil immersed transformer to measure stress, strain, structural damage and the like in the structures;
(4) according to the automatic detection device for the insulating oil holding amount of the oil immersed transformer, natural compatibility exists between the measuring probe and the optical fiber, optical fiber linkage is easy, the spectral characteristic is good, the loss is small, and the reliability is high;
(5) according to the automatic detection device for the insulating oil holding amount of the oil immersed transformer, the probe shell is made of stainless steel materials, so that the corrosion resistance is good, and the device can meet the requirements of engineering structures on various complicated and severe working conditions.
Drawings
Fig. 1 is a block diagram of a fuel quantity monitoring system according to the present invention.
Fig. 2 is a block diagram of the fiber sensing system according to the present invention.
FIG. 3 is a graph of the hydraulic response of the present invention.
Fig. 4 is a view showing the structure of a measuring probe according to the present invention.
Detailed Description
The following further describes the embodiments of the present invention with reference to the drawings.
Referring to fig. 1-4, the automatic detection device for the insulation oil retention of oil-immersed transformer of the present invention is characterized in that it comprises a plurality of measuring probes embedded in the oil-immersed transformer, a shunt connected to the plurality of measuring probes, a filter and demodulator connected to the shunt, a data processor connected to the filter and demodulator, a computer connected to the data processor, a monitoring center connected to the computer,
each measuring probe comprises a housing 8, an oil penetration hole 1 and an oil penetration net 2 which are arranged at the bottom of the housing 8, an elastic diaphragm 3 which is arranged inside the housing 8, an optical fiber pressure sensor 4 which is arranged in the housing 8 and is attached to the elastic diaphragm 3, an optical fiber 7 which is arranged in the optical fiber pressure sensor 4, an optical fiber fastening mechanism 5 which is connected with the optical fiber pressure sensor 4 and an optical fiber protection connector 6.
The splitter is connected with a plurality of measuring probes through optical fibers 7, and distributed arrangement of the optical fiber pressure sensors 4 is achieved.
The filtering and demodulating device comprises a light source, a signal filter and a signal demodulator.
The optical fiber 7 is a single mode optical fiber, and the wavelength range is as follows: 1530-1570 nm; the wavelength resolution is: 1 pm; and (3) drift calibration: 10 pm; loss: 12 dB; scanning frequency: 50 HZ.
The transformer oil is mainly used for filling gaps inside or among poles of solid materials in the transformer, so that the dielectric property of the transformer is improved, and the heat dissipation capacity of equipment is improved. In order to keep the amount of insulating oil in the transformer within a certain reasonable interval, the transformer oil needs to be accurately detected in real time.
In order to realize real-time and accurate detection of the retention amount of insulating oil in the transformer, a certain amount of oil pressure measuring probes are vertically suspended at each detection point in an oil tank of the transformer according to the structural characteristics and the specified oil injection amount of the transformer; an optical fiber pressure sensor 4 is arranged in the oil pressure measuring probe, and the measuring principle is that one end of the optical fiber pressure sensor 4 is fixed with the elastic diaphragm 3, and the other end of the optical fiber pressure sensor is fixed with a mechanical structure in the measuring probe; when the elastic diaphragm 3 is subjected to the action of external force generated by oil pressure, the elastic diaphragm deforms to cause the wavelength change of the optical fiber pressure sensor 4, the oil pressure is measured by detecting the wavelength change, and the oil level can be calculated according to the oil pressure, so that the real-time accurate detection of the holding amount of the insulating oil at each point in the transformer is realized.
Referring to fig. 1, the oil quantity monitoring system is composed of a plurality of measuring probes, a shunt, a filter and demodulator, a data processor, a computer and a monitoring center. The splitter is connected with a plurality of measuring probes by optical fibers 7 to realize distributed arrangement of the sensors; the filtering and demodulating device filters and demodulates the oil pressure signal, and mainly comprises a light source, a signal filter, a signal demodulator and other main devices. The computer collects the information transmitted by the data processor, and displays the data of the insulating oil holding amount of each measuring point in real time, and the monitoring center can realize remote real-time online detection. The measuring signal is an optical signal transmitted through the optical fiber 7, no current or voltage is loaded in the measuring probe immersed in the oil, and the device is absolutely a flame-proof and explosion-proof detecting device. The oil pressure measurement adopts optical signal detection, no heat is generated, and the stainless steel outer cover 8 is used for protection and isolation; therefore, the transformer oil is not polluted, and the adverse effects of transformer oil aging and the like are not caused. The optical fiber sensing probe adopted by the utility model is a passive sensor, is not influenced by an electromagnetic field, is electrically insulated, corrosion-resistant, high-voltage-resistant and good in safety, and is suitable for the strong electromagnetic field environment of an oil immersed transformer. The front end of the optical fiber oil pressure measuring probe is provided with an oil seepage hole 1 and an oil penetration net 2, so that the optical fiber oil pressure measuring probe can be effectively prevented from being polluted by particulate matters in transformer oil.
Referring to fig. 2, the optical fiber sensing system is composed of a light source, an optical fiber pressure sensor 4, a coupler, a filter, a detector, an amplifier, a divider, and the like. The optical fiber pressure sensor 4 is a passive device in which the refractive index of a medium in the fiber core of the optical fiber is periodically modulated, and the wavelength of the wave peak of the reflected or transmitted light wave is related to the modulation period of the refractive index of the optical fiber pressure sensor 4 and the refractive index of the fiber core. The change of the external pressure directly affects the change of the reflected or transmitted wavelength of the optical fiber pressure sensor 4, and according to the optical fiber sensing coupling theory, when the phase matching condition is satisfied, the optical fiber sensing relationship is given by the formula (1):
λ＝2nA (1)
in the formula, λ is the central wavelength of the reflected light of the optical fiber pressure sensor 4, n is the effective refractive index of the fiber core, and a is the sensitive period of the optical fiber sensing. When the external pressure changes, the central wavelength is changed. The variation of the center wavelength of the optical fiber sensor obtained by differentiating the formula (1) is as follows:
Δλ＝2nΔA+2ΔnA (2)
wherein Δ a is the elastic deformation of the optical fiber under the action of external stress, and Δ n is the change caused by the elasto-optic effect of the optical fiber. The variation of the oil pressure to be measured can be obtained by detecting the offset of the central wavelength in real time and according to the linear relation between delta A and delta n and the oil pressure to be measured, and the key of the optical fiber pressure sensor 4 is to effectively detect the variation of the central wavelength.
The signal demodulation process of the optical fiber pressure sensor 4 is shown in fig. 2, light emitted by the optical fiber 7 enters the optical fiber sensing probe through the coupler I, light reflected by the optical fiber pressure sensor 4 is divided into two beams of light with equal intensity through the coupler II, wherein one beam of light passes through the filter and then is detected and amplified to form filtering signal light I1The other path of light is directly detected and amplified to become reference light I0(ii) a The filter function of the filter is:
F(λ)＝B(λ-λ0) (3)
wherein B is the slope of the filter curve of the filter, λ0Is F (lambda)0) Output wavelength at 0. The two paths of light are divided by a divider to eliminate the influence of optical power, and the obtained variable quantity output of the wavelength is as follows:
in the formula, λBIs the central wavelength, Delta lambda, of the optical fiber sensor in the natural elongation stateBIs the detected wavelength variation of the optical fiber sensor.
The method adopted by the utility model is suitable for dynamic and static oil pressure detection, the output signal and the wavelength offset are in a linear relation, and the influence of light source power fluctuation and additional loss of connection at each position is eliminated.
Referring to fig. 3, it can be seen from the oil pressure response graph that the sensor linear response is very good, with a 3.158nm wavelength change per 10m oil level, so with high accuracy demodulation up to 1pm, the oil level monitoring accuracy can be up to 0.5mm or less.
Referring to fig. 4, the optical fiber sensing oil pressure measuring probe is composed of an outer cover 8, an oil penetration hole 1, an oil penetration net 2, an elastic diaphragm 3, an optical fiber pressure sensor 4, an optical fiber 7, an optical fiber fastening mechanism 5 and an optical fiber protection connector 6. The stainless steel outer cover 8 has enough protection strength and corrosion resistance. The measuring probe is vertically placed into the oil-immersed transformer. The transformer oil gets into from oil leakage hole 1, acts on elastic diaphragm 3 with the oil pressure through oil leakage net 2, receives the exogenic action when elastic diaphragm 3 and produces deformation to arouse the change of pasting 4 wavelength of optical fiber pressure sensor on elastic diaphragm 3, realize the measurement of oil pressure through the change of detection wavelength.
The optical fiber used in the utility model is a single mode optical fiber, and the wavelength range is as follows: 1530-1570 nm; the wavelength resolution is: 1 pm; and (3) drift calibration: 10 pm; loss: 12 dB; scanning frequency: 50 HZ; a maximum of 30 fiber optic pressure sensors 4 can be formed. The utility model encapsulates the fiber pressure sensor 4 with the center wavelength of 1549nm in a 1mm metal sleeve by epoxy resin, then sticks the fiber pressure sensor on the elastic diaphragm 3 by acrylic acid, and sticks a strain gauge on the elastic diaphragm 3 which is close to the fiber pressure sensor.
The automatic detection device for the insulating oil retention of the oil immersed transformer can realize the automatic detection of the insulating oil retention of the oil immersed transformer, and a monitoring center can know the dynamic change condition of the insulating oil retention in the oil immersed transformer on line in real time; the change condition of the insulating oil liquid level in the oil-immersed transformer can be well recorded, and early warning information of the insulating oil holding amount can be given by combining the design parameters of the oil-immersed transformer, so that the method has very important significance on the safe operation of the oil-immersed transformer; compared with the traditional electric sensor, the measuring signal is an optical signal transmitted out of the optical fiber 7, and no current or voltage is loaded on the sensor immersed in oil, so that the sensor is flame-proof and explosion-proof, and is absolutely safe in physical sense; the measuring probe has simple structure, small volume, light weight and variable appearance, and is particularly suitable for being embedded into large structures such as oil immersed transformers to measure the stress, strain, structural damage and the like in the structures; the natural compatibility exists between the measuring probe and the optical fiber 7, the optical fiber is easy to link, the spectral characteristic is good, the loss is small, and the reliability is high; the shell of the probe is made of stainless steel material, has good corrosion resistance and can meet the requirements of engineering structures on various complex and severe working conditions.
Claims (4)
1. An automatic detection device for the quantity of insulating oil in oil immersed transformer is composed of several measuring probes embedded in oil immersed transformer, shunt connected to said probes, filter and demodulator connected to said shunt, data processor connected to said filter and demodulator, computer connected to said data processor, and monitor center connected to said computer,
each measuring probe comprises an outer cover, an oil seepage hole and an oil seepage net which are arranged at the bottom of the outer cover, an elastic diaphragm arranged in the outer cover, an optical fiber pressure sensor arranged in the outer cover and attached to the elastic diaphragm, an optical fiber arranged in the optical fiber pressure sensor, an optical fiber fastening mechanism connected with the optical fiber pressure sensor and an optical fiber protection connector.
2. The oil immersed transformer insulating oil holding amount automatic detection device according to claim 1, wherein the splitter is connected with a plurality of measurement probes through optical fibers, so that distributed arrangement of optical fiber pressure sensors is realized.
3. The automatic oil-filled transformer insulating oil remaining amount detection device according to claim 1, wherein the filter and demodulator comprises a light source, a signal filter and a signal demodulator.
4. The automatic detection device for the insulation oil retention of oil-immersed transformer according to claim 1, wherein the optical fiber is a single mode optical fiber, and the wavelength range is as follows: 1530-1570 nm; the wavelength resolution is: 1 pm; and (3) drift calibration: 10 pm; loss: 12 dB; scanning frequency: 50 HZ.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202121862443.3U CN215677198U (en) | 2021-08-11 | 2021-08-11 | Automatic detection device for insulation oil holding quantity of oil immersed transformer |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202121862443.3U CN215677198U (en) | 2021-08-11 | 2021-08-11 | Automatic detection device for insulation oil holding quantity of oil immersed transformer |
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| CN215677198U true CN215677198U (en) | 2022-01-28 |
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| CN202121862443.3U Active CN215677198U (en) | 2021-08-11 | 2021-08-11 | Automatic detection device for insulation oil holding quantity of oil immersed transformer |
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2021
- 2021-08-11 CN CN202121862443.3U patent/CN215677198U/en active Active
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