CN202083463U - Eddy-current transducer capable of resisting shaft vibration caused by magnetic flux leakage interference of excitation lead wire - Google Patents
Eddy-current transducer capable of resisting shaft vibration caused by magnetic flux leakage interference of excitation lead wire Download PDFInfo
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- CN202083463U CN202083463U CN2011201957036U CN201120195703U CN202083463U CN 202083463 U CN202083463 U CN 202083463U CN 2011201957036 U CN2011201957036 U CN 2011201957036U CN 201120195703 U CN201120195703 U CN 201120195703U CN 202083463 U CN202083463 U CN 202083463U
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- pass filter
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- eddy
- current transducer
- excitation lead
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Abstract
The utility model discloses an eddy-current transducer capable of resisting shaft vibration caused by the magnetic flux leakage interference of an excitation lead wire. The eddy-current transducer comprises a front-mounted device, wherein the front-mounted device is provided with an oscillator, a geophone, a low-pass filter, an output amplifier and a high-pass filter, wherein the output end of the oscillator is connected with the high-pass filter, and the output end of the high-pass filter is connected with the geophone. The eddy-current transducer has the advantages of simple and reasonable design, practicability and wider application range; excitation lead wire-based leakage magnetic field interference resistance of the eddy-current transducer is well improved as the high-pass filter is provided; the requirement on monitoring the vibration of an excitation-side shaft of an electric generator of a double water-cooling type steam turbine generator unit is met; and the problem of excitation interference is solved.
Description
Technical field
The utility model relates to the current vortex sensor field, particularly relates to a kind of anti-excitation lead leakage field and disturbs the axle current vortex sensor that shakes.
Background technology
In the rotating machinery monitoring system, current vortex sensor is widely used in the fields of measurement of displacement, mechanical vibration amplitude and metal material thickness etc. owing to have advantages such as measurement range is big, highly sensitive, antijamming capability by force, is not subjected to the greasy dirt medium influence, simple in structure, easy for installation, untouchable measurement.
At present, Turbo-generator Set generally adopts Water Cooling Technology.And water-cooled generator is owing to be connected with chilled water in the macro-axis center pit, so excitation lead passes through from the eccentric orfice of center pit both sides, exciting current can produce magnetic field on diameter of axle surface, and the induction electromotive force of probe is caused in this magnetic field, thereby makes the output valve of current vortex sensor produce big offset error.When being installed near the vortex sensor measuring shaft vibration the excitation electromotor, the axle value of shaking is generally bigger than normal, and the axle of a lot of units monitor value that shakes has surpassed the protection working value of stipulating, makes that the generator protection system can't operate as normal.Related experiment data through the inventor draw, the output voltage swing trend that vibration causes roughly is sinusoidal wave tendency, and on this basis each cycle about twice tangible spike appearred, and this spike just in time with the unit electric current correspondence that puts into excitation.Like this, the situation that excitation is disturbed is more serious, is badly in need of design a solution and solves this problem.
The utility model content
The technical problems to be solved in the utility model provides a kind of anti-excitation lead leakage field and disturbs the axle current vortex sensor that shakes, purpose is to improve the anti-excitation lead stray field of eddy current sensor interference capability, to satisfy the monitoring requirement to two water-cooled turbogenerator group generator excitation side shaft vibrations.
For solving the problems of the technologies described above, the utility model is achieved through the following technical solutions: a kind of anti-excitation lead leakage field disturbs the axle current vortex sensor that shakes, comprise fore-lying device, this fore-lying device is provided with oscillator, wave detector, low-pass filter, output amplifier and Hi-pass filter, the output terminal of described oscillator connects described Hi-pass filter, and the output terminal of described Hi-pass filter connects described wave detector.
Further technical scheme, the output terminal of described wave detector connects described low-pass filter.
Technical scheme further, the output terminal of described low-pass filter connects described output amplifier.
Compared with prior art, the beneficial effects of the utility model are: simplicity of design is reasonable, add Hi-pass filter and improved the anti-excitation lead stray field of eddy current sensor interference capability well, satisfied monitoring requirement two water-cooled turbogenerator group generator excitation side shaft vibrations; Current vortex sensor after the improvement, filtering the induction electromotive force composition that superposes in the oscillator signal, the spacing of probe coil and tested metal surface changes the amplitude modulation(PAM) that oscillator signal is realized then can pass through Hi-pass filter, carry out demodulation by detecting circuit again through the oscillator signal after the high pass filter, processes, thereby obtain directly to reflect the voltage signal of mechanical vibration, the excitation interference problem that the utility model solves is very practical, and range of application is also relatively wider.
Description of drawings
Fig. 1 disturbs the shake functional-block diagram of current vortex sensor of axle for the anti-excitation lead leakage field of the utility model;
Fig. 2 is the functional-block diagram of current vortex sensor in the prior art;
Output waveform figure when Fig. 3 experimentizes for Beijing Hao Ruisi MLW330104 eddy current sensor;
Fig. 4 disturbs axle current vortex sensor and Beijing Hao Ruisi MLW330104 eddy current sensor output waveform figure when carrying out control experiment that shakes for the anti-excitation lead leakage field of the utility model.
Embodiment
The utility model is described in further detail below in conjunction with drawings and the specific embodiments.
As shown in Figure 1, a kind of anti-excitation lead leakage field disturbs the axle current vortex sensor that shakes, and comprises fore-lying device, and this fore-lying device is provided with oscillator, wave detector, low-pass filter, output amplifier and Hi-pass filter.The output terminal of described oscillator connects described Hi-pass filter, and the output terminal of described Hi-pass filter connects described wave detector.The output terminal of described wave detector connects described low-pass filter, and the output terminal of described low-pass filter connects described output amplifier.
Compare with prior art shown in Figure 2, the utility model has added Hi-pass filter, has improved the anti-excitation lead stray field of eddy current sensor interference capability well, has satisfied the monitoring requirement to two water-cooled turbogenerator group generator excitation side shaft vibrations; Current vortex sensor after the improvement, filtering the induction electromotive force composition that superposes in the oscillator signal, the spacing of probe coil and tested metal surface changes the amplitude modulation(PAM) that oscillator signal is realized then can pass through Hi-pass filter, carry out demodulation by detecting circuit again through the oscillator signal after the high pass filter, processes, thereby obtain voltage signal.
The current vortex sensor of the foregoing description is made up of probe and fore-lying device, fore-lying device drives probe coil and produces high frequency magnetic field, this high frequency magnetic field produces current vortex in the metal surface, current vortex conversely can be to probe coil generation effect, the fore-lying device circuit can be handled this counteractive power, output voltage signal representing the spacing between tested metal surface and the coil, thereby is realized non-cpntact measurement to the measured surface vibration.If there is magnetic field in tested metal surface, moving that the magnetic induction density variation in this magnetic field or magnetic field are relative with probe all can produce induction electromotive force in the probe coil of current vortex sensor, thereby has influence on the output voltage of sensor.
The inventor has adopted the mode of contrast test to verify diamagnetic validity of disturbing design of the utility model.The mode of experiment is as follows:
Be used as tested metal surface with a fine aluminium matter target disc.During the aluminium disc spins, its card has certain circle to beat, and the inventor beats with this and simulates the vibration of metal surface.(target disc thickness 3mm) bonding two magnet steel at the target disc back side, the penetrable target disc in the magnetic field of its generation impacts the probe of current vortex sensor.When rotating speed rotation that the aluminum target disc changes with per minute 3000, probe coil is streaked in the magnetic field that magnet steel produces fast, produces induction electromotive force on probe coil, and restore the waveform characteristic of this alternating magnetic field on the fore-lying device output signal.
The inventor is that anti-excitation lead leakage field of the present utility model disturbs the shake 8mm bore current vortex sensor of current vortex sensor and Beijing Hao Ruisi of axle in order to contrast test.The sensitivity of two sensors is 8V/mm, and output voltage range is-and 2V is to-18V.
As shown in Figure 3, Fig. 3 is the output waveform figure of Beijing Hao Ruisi MLW330104 eddy current sensor.Among Fig. 3, the waveform in the dashed rectangle square frame is exactly the spike waveform that excitation is disturbed, and the peak-to-peak value of this waveform reaches 3V.Waveform in the solid-line rectangle frame is exactly that target disc is beated at the imbalance circle that high speed rotating is, peak-to-peak value is about 300mV.Other experimental data is as follows:
Sensor gap voltage :-13.8V
The sensitivity of sensor and fore-lying device combination: 8V/mm
Target disc rotating speed: 3000 rev/mins
Fore-lying device output peak value: 3.02V
Fore-lying device output frequency: 100Hz
As shown in Figure 4, Fig. 4 disturbs axle current vortex sensor and Beijing Hao Ruisi MLW330104 eddy current sensor output waveform figure when carrying out control experiment that shakes for the anti-excitation lead leakage field of the utility model.Other experimental data is as follows:
Sensor gap voltage :-15.4V
The sensitivity of sensor and fore-lying device combination: 7.9V/mm
Target disc rotating speed: 3000 rev/mins
Fore-lying device output peak value: 330mV
Fore-lying device output frequency: 50Hz
From above experimental result parameter, measure same target disc, the anti-excitation lead leakage field of the utility model disturbs the axle current vortex sensor output of shaking not have the excitation interference, and the excitation spike of the 3V peak-to-peak value of the fore-lying device of Beijing Hao Ruisi current vortex sensor output has been filtered fully, output be the circle of target disc under the high speed rotating waveform of beating.
This experimental result confirms: the utility model has solved the problem that excitation is disturbed well.
Need to prove at last; the above only is preferred embodiment of the present utility model; rather than to the qualification of technical solutions of the utility model, any the utility model technical characterictic being equal to of being done replaced or corresponding improvement, still within protection domain of the present utility model.
Claims (3)
1. an anti-excitation lead leakage field disturbs the axle current vortex sensor that shakes, comprise fore-lying device, this fore-lying device is provided with oscillator, wave detector, low-pass filter and output amplifier, it is characterized in that: described fore-lying device also is provided with Hi-pass filter, the output terminal of described oscillator connects described Hi-pass filter, and the output terminal of described Hi-pass filter connects described wave detector.
2. anti-excitation lead leakage field according to claim 1 disturbs the axle current vortex sensor that shakes, and it is characterized in that: the output terminal of described wave detector connects described low-pass filter.
3. anti-excitation lead leakage field according to claim 1 disturbs the axle current vortex sensor that shakes, and it is characterized in that: the output terminal of described low-pass filter connects described output amplifier.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011201957036U CN202083463U (en) | 2011-06-10 | 2011-06-10 | Eddy-current transducer capable of resisting shaft vibration caused by magnetic flux leakage interference of excitation lead wire |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011201957036U CN202083463U (en) | 2011-06-10 | 2011-06-10 | Eddy-current transducer capable of resisting shaft vibration caused by magnetic flux leakage interference of excitation lead wire |
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| Publication Number | Publication Date |
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| CN202083463U true CN202083463U (en) | 2011-12-21 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN2011201957036U Expired - Fee Related CN202083463U (en) | 2011-06-10 | 2011-06-10 | Eddy-current transducer capable of resisting shaft vibration caused by magnetic flux leakage interference of excitation lead wire |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111537112A (en) * | 2020-05-07 | 2020-08-14 | 上海工业自动化仪表研究院有限公司 | Excitation signal generator for magnetoelastic sensor |
| CN111669171A (en) * | 2020-05-21 | 2020-09-15 | 深圳市知用电子有限公司 | Signal isolation transmission device |
| CN112130067A (en) * | 2020-09-02 | 2020-12-25 | 国网天津市电力公司电力科学研究院 | Online monitoring system and monitoring identification method for magnetic leakage fault of large generator |
| CN117110417A (en) * | 2022-11-22 | 2023-11-24 | 北华航天工业学院 | Eddy current probe circuit system during magnetic leakage-eddy current composite detection |
-
2011
- 2011-06-10 CN CN2011201957036U patent/CN202083463U/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111537112A (en) * | 2020-05-07 | 2020-08-14 | 上海工业自动化仪表研究院有限公司 | Excitation signal generator for magnetoelastic sensor |
| CN111669171A (en) * | 2020-05-21 | 2020-09-15 | 深圳市知用电子有限公司 | Signal isolation transmission device |
| CN112130067A (en) * | 2020-09-02 | 2020-12-25 | 国网天津市电力公司电力科学研究院 | Online monitoring system and monitoring identification method for magnetic leakage fault of large generator |
| CN112130067B (en) * | 2020-09-02 | 2024-04-23 | 国网天津市电力公司电力科学研究院 | Large-scale generator magnetic flux leakage fault on-line monitoring system and monitoring identification method |
| CN117110417A (en) * | 2022-11-22 | 2023-11-24 | 北华航天工业学院 | Eddy current probe circuit system during magnetic leakage-eddy current composite detection |
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| Date | Code | Title | Description |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20111221 Termination date: 20140610 |