CN101762715B - Method for measuring rotor speed of turbo generator and device thereof - Google Patents
Method for measuring rotor speed of turbo generator and device thereof Download PDFInfo
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- CN101762715B CN101762715B CN2009102144800A CN200910214480A CN101762715B CN 101762715 B CN101762715 B CN 101762715B CN 2009102144800 A CN2009102144800 A CN 2009102144800A CN 200910214480 A CN200910214480 A CN 200910214480A CN 101762715 B CN101762715 B CN 101762715B
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Abstract
The invention discloses a method for measuring the rotor speed of a turbo generator and a device thereof. The method comprises the following steps: converting the rotor speed into a pulse electrical signal through a sensor; carrying out F/V conversion on the pulse electrical signal, wherein U(f) refers to the converted voltage signal, f refers to the pulse electrical signal, f1 and f2 refer to two predetermined pulse electrical signal values, Umax refers to a predetermined voltage value; carrying digital-to-analogue conversion on the voltage signal after the F/V conversion; and converting the voltage signal after the F/V conversion into digital quantity through a data acquisition unit. In the method, F/V conversion is carried out on the pulse electrical signals by stages, with respect to the voltage signal which is converted according to the U(f) = f*k1 linear form in prior art 2, because k is more than k1, the frequency range corresponding to the converted voltage signal in the predetermined scope is small, and the caused linear error is also small, the measurement is insusceptible to interference wave, and the measurement error of the rotor speed is small.
Description
Technical field
The present invention relates to turbodynamo, relate in particular to a kind of measuring method and device thereof of rotor speed of turbo generator.
Background technology
The measurement mechanism of many rotor speed of turbo generator is to adopt sensor, F/V (frequency/voltage, frequency/voltage) converting unit, data acquisition unit to realize.During rotor rotation, sensor changes rotor speed into pulse electrical signal, changes voltage signal into through the F/V converting unit, changes voltage signal into digital quantity by data acquisition unit again, finishes the measurement of rotor speed of turbo generator.
In Load Rejecting Test of Turbine-generator Units, rotor speed changes very fast, the raising speed rate can reach 280～400r/min in the initial 40～110ms that ascends to heaven of rotor, measuring accuracy and response speed to rotor speed have higher requirement, the analysis showed that if getting raising speed rate tangential length is 40ms, corresponding change in rotational speed amount is 12～15r/min, if measuring error is ± 1r/min that the error that then causes can reach ± 6.25-8.33%.So the F/V converting unit plays very important effect.
F/V converting unit in the measurement mechanism of prior art one adopts mimic channel, and the little and anti-space electric field interference of power supply noise is poor.Fig. 1 is the data that the measurement mechanism of use the prior art one in the Load Rejecting Test of Turbine-generator Units measures, and wherein ordinate is represented rotor speed, and unit is r/min, and horizontal ordinate express time, unit are s; Fig. 2 is the measurement data in the preceding 0.4s, and wherein ordinate is represented rotor speed, and unit is r/min, and horizontal ordinate express time, unit are s.The measurement range of the measurement mechanism of the prior art one is 0～5000r/min, is output as 0～10V.By analysis, measurement mechanism is subjected to the influence of electromagnetic field (50Hz), and the interference wave of 80mv is arranged, and is equivalent to 40r/min, for Load Rejecting Test of Turbine-generator Units (2750～3250Hz) frequency range, its signal to noise ratio (S/N ratio) is little, measuring error is big.
F/V converting unit in the measurement mechanism of prior art two adopts digital circuit, is the improvement to prior art one, and the big and anti-space electric field interference of its power supply noise is good.Fig. 3 is data of using the measurement mechanism measurement of the prior art two in the Load Rejecting Test of Turbine-generator Units, and wherein ordinate is represented rotor speed, and unit is r/min, and horizontal ordinate express time, unit are s; Fig. 4 is the measurement data in the preceding 0.4s, and wherein ordinate is represented rotor speed, and unit is r/min, and horizontal ordinate express time, unit are s.The measurement range of the measurement mechanism of the prior art two is 0～5000Hz, be output as 0～5V, by analysis, measurement mechanism is subjected to the influence of white noise, the interference wave of 20mv is arranged, be equivalent to 20r/min, for Load Rejecting Test of Turbine-generator Units (2750～3250Hz) frequency range, its signal to noise ratio (S/N ratio) is general, and measuring error is bigger.
Summary of the invention
The invention provides a kind of measuring method and device thereof of rotor speed of turbo generator, its rotor speed measuring error is less.
Technical scheme of the present invention is:
A kind of measuring method of rotor speed of turbo generator comprises step:
Change rotor speed into pulse electrical signal by sensor;
Described pulse electrical signal is pressed
Carry out the F/V conversion,
Wherein
The magnitude of voltage of the voltage signal after U (f) the expression conversion, the frequency values of f indicating impulse electric signal, f
1, f
2Be the frequency values of two predetermined pulse electrical signals, U
MaxBe scheduled voltage;
Voltage signal after the described F/V conversion is carried out digital-to-analog conversion;
Be converted to digital quantity by the voltage signal of data acquisition unit after with described digital-to-analog conversion.
A kind of measurement mechanism of rotor speed of turbo generator, comprise sensor, F/V converting unit, D/A conversion unit and data acquisition unit, the output terminal of described sensor is connected by described F/V converting unit, D/A conversion unit and described data acquisition unit successively;
Described sensor outputs to described F/V converting unit after rotor speed is converted to pulse electrical signal, and described F/V converting unit is pressed described pulse electrical signal
Carry out the F/V conversion, wherein
The magnitude of voltage of the voltage signal after U (f) the expression conversion, the frequency values of f indicating impulse electric signal, f
1, f
2Be the frequency values of two predetermined pulse electrical signals, U
MaxBe scheduled voltage; The voltage signal of described D/A conversion unit after to described F/V conversion carries out outputing to described data acquisition unit after the digital-to-analog conversion, and the voltage signal of described data acquisition unit after with described digital-to-analog conversion is converted to digital quantity.
The measuring method of rotor speed of turbo generator of the present invention and device thereof, the paired pulses electric signal is pressed
Carry out the F/V conversion, promptly the paired pulses electric signal carries out the F/V conversion stage by stage, with respect to pressing U (f)=f * k in the prior art two
1The voltage signal that form of straight lines is changed (as Figure 11) is because slope k＞k
1, then the frequency range of the voltage signal correspondence in the preset range after the conversion is smaller, and the linear error that causes is also just smaller, is not subject to the influence of interference wave, and the tachometric survey error ratio is less.
Description of drawings
Fig. 1 is the schematic diagram data that uses measurement mechanism to measure in the Load Rejecting Test of Turbine-generator Units in the prior art one;
Fig. 2 is the local measurement data in the preceding 0.4s among Fig. 1;
Fig. 3 is the schematic diagram data that uses measurement mechanism to measure in the Load Rejecting Test of Turbine-generator Units in the prior art two;
Fig. 4 is the local measurement data in the preceding 0.4s among Fig. 3;
Fig. 5 is the measuring method process flow diagram in one embodiment of rotor speed of turbo generator of the present invention;
Fig. 6 is the measuring method process flow diagram in another embodiment of rotor speed of turbo generator of the present invention;
Fig. 7 is the measurement mechanism structured flowchart in one embodiment of rotor speed of turbo generator of the present invention;
Fig. 8 is the measurement mechanism structured flowchart in another embodiment of rotor speed of turbo generator of the present invention;
Fig. 9 is the schematic diagram data that uses method of the present invention or measurement device in the Load Rejecting Test of Turbine-generator Units;
Figure 10 is the local measurement data in the preceding 0.4s among Fig. 9;
Figure 11 is that F/V converting unit of the present invention is carried out F/V data converted synoptic diagram in one embodiment;
Figure 12 is the noiseproof feature test pattern to F/V converting unit of the present invention.
Embodiment
The measuring method of rotor speed of turbo generator of the present invention and device thereof, the paired pulses electric signal is pressed
Carry out the F/V conversion, promptly the paired pulses electric signal carries out the F/V conversion stage by stage, with respect to pressing U (f)=f * k in the prior art two
1The voltage signal that form of straight lines is changed (as Figure 11) is because slope k＞k
1, then the frequency range of the voltage signal correspondence in the preset range after the conversion is smaller, and the linear error that causes is also just smaller, is not subject to the influence of interference wave, and the tachometric survey error ratio is less.
Below in conjunction with accompanying drawing specific embodiments of the invention are done a detailed elaboration.
The measuring method of rotor speed of turbo generator of the present invention as Fig. 5, comprises step:
S101, change rotor speed into pulse electrical signal by sensor;
S102, described pulse electrical signal is pressed
Carry out the F/V conversion, promptly frequency is to the conversion of voltage signal; Wherein
The magnitude of voltage of the voltage signal after U (f) the expression conversion, the frequency values of f indicating impulse electric signal, f
1, f
2Be the frequency values of two predetermined pulse electrical signals, U
MaxBe scheduled voltage; This step is to adopt the scheme paired pulses electric signal of conversion stage by stage to change, and the phase one voltage signal of conversion is 0, and voltage signal is a straight line, and the shape of the voltage signal of subordinate phase conversion is an oblique line, and the voltage signal of phase III is U
Max, voltage signal also is a straight line;
S103, the voltage signal after the described F/V conversion is carried out digital-to-analog conversion;
S104, be converted to digital quantity by the voltage signal of data acquisition unit after, to finish the measurement of rotor speed with described digital-to-analog conversion.
In a preferred embodiment, between step S101 and step S102, promptly before described pulse electrical signal being carried out the F/V conversion,, also comprise step S1010 as Fig. 6:
Described pulse electrical signal is carried out differential operational handle,, and the signal waveform after the differential operational processing is carried out shaping handle with the interference of minimizing common mode input signal.Signal waveform after this differential operational processing is carried out shaping handle, can reduce the influence of spiking, so that better described pulse electrical signal is carried out the F/V conversion.
Described pulse electrical signal among the step S102 is updated to the signal after described shaping is handled at this moment.
In a preferred embodiment, between step S103 and step S104, promptly before being converted to digital quantity,, also comprise step as Fig. 6 by the voltage signal of data acquisition unit after with described digital-to-analog conversion:
Voltage signal after the described digital-to-analog conversion is carried out low-pass filtering treatment, can be so that the voltage signal curve of digital-to-analog conversion be smoother, and interference that can the filtering spiking.
Voltage signal after the described digital-to-analog conversion among this moment step S104 is updated to the signal after the described low-pass filtering treatment.
Measuring method of the present invention especially can be applied in the rotor speed measurement of load dump test, can improve the accuracy of the rotor characteristic values such as rotor initial acceleration of load dump test measurement, because load dump test rotor tachometer value is at 2750～3250r/min, so can be with f in load dump test
1, f
2And U
MaxBe set at f respectively
1=2500Hz, f
2=3500Hz, U
Max=5V (certain f
1, f
2And U
MaxSetting also can set according to actual needs), as Figure 11, horizontal ordinate indicating impulse electric signal, unit is Hz, ordinate is represented voltage signal, unit is V, A is a F/V transformation curve of the prior art, and B is for using the present invention's curve of F/V conversion stage by stage, as we can see from the figure the present invention stage by stage the curve of F/V conversion be divided into for three stages, the phase one voltage signal of conversion is 0, be a horizontal linear, the voltage signal of subordinate phase conversion be shaped as oblique line, the slope of this oblique line is (5-0)/(3500-2500)=0.005, the phase III voltage signal of conversion is 5V, also is a horizontal linear.Voltage signal in the prior art after the conversion be shaped as oblique line, the slope of this oblique line is 5/5000=0.001.If measuring method of the present invention and measuring method of the prior art are all exported the interference wave of 50mv, the error (1000Hz/V) that then is equivalent to 50Hz in the prior art, the present invention only is equivalent to the error (200Hz/V) of 10Hz, the linear error that this shows measuring method of the present invention is much smaller, promptly be because the present invention adopts the technical scheme of conversion stage by stage, make in the slope ratio of the oblique line of the voltage signal of load dump test 2750～3250Hz internal conversion bigger, the frequency range of the voltage signal correspondence in the preset range will be fewer like this, the linear error that causes is also just smaller, is not subject to the influence of interference wave.
Corresponding with measuring method of the present invention, the present invention has also disclosed a kind of measurement mechanism of rotor speed of turbo generator, as Fig. 7, comprise sensor, F/V converting unit, D/A conversion unit and data acquisition unit, the output terminal of described sensor is connected by described F/V converting unit, D/A conversion unit and described data acquisition unit successively;
Described sensor outputs to described F/V converting unit after rotor speed is converted to pulse electrical signal, and described F/V converting unit is pressed described pulse electrical signal
Carry out the F/V conversion, wherein
The magnitude of voltage of the voltage signal after U (f) the expression conversion, the frequency values of f indicating impulse electric signal, f
1, f
2Be the frequency values of two predetermined pulse electrical signals, U
MaxBe scheduled voltage; The voltage signal of described D/A conversion unit after to described F/V conversion carries out outputing to described data acquisition unit after the digital-to-analog conversion, and the voltage signal of described data acquisition unit after with described digital-to-analog conversion is converted to digital quantity.
In a preferred embodiment, as Fig. 8, measurement mechanism of the present invention also comprises: differential input block and signal reshape unit, the input end of described differential input block is connected with the output terminal of described sensor, and the output terminal of described differential input block is connected by the input end of described signal reshape unit with described F/V converting unit;
Described differential input block carries out outputing to described signal reshape unit after differential operational is handled to the pulse electrical signal of described sensor output, and the signal waveform after described signal reshape unit is handled this differential operational carries out outputing to described F/V converting unit after shaping is handled.Differential operational is handled the interference that can reduce common mode input signal, and the signal waveform after this differential operational is handled is carried out the shaping processing, can reduce the influence of spiking, so that better described pulse electrical signal is carried out the F/V conversion.
In this preferred embodiment, measurement mechanism of the present invention, as Fig. 8, also comprise: low-pass filter unit, be connected between the input end of the output terminal of described D/A conversion unit and described data acquisition unit, the voltage signal after the described D/A conversion unit digital-to-analog conversion is carried out outputing to described data acquisition unit after the low-pass filtering treatment.Voltage signal after the described digital-to-analog conversion is carried out low-pass filtering treatment, can be so that the voltage signal curve of digital-to-analog conversion be smoother, and interference that can the filtering spiking.
Measurement mechanism of the present invention especially is suitable for use in the rotor speed measurement of load dump test, can improve the accuracy of the rotor characteristic values such as rotor initial acceleration of load dump test measurement, because load dump test rotor tachometer value is at 2750～3250r/min, so the F/V converting unit can be with f in load dump test
1, f
2And U
MaxBe set at f respectively
1=2500Hz, f
2=3500Hz, U
Max=5V (certain f
1, f
2And U
MaxAlso can set other values as required).
As Fig. 9 is the rotor speed synoptic diagram that adopts measuring method of the present invention or measurement mechanism to measure, and wherein ordinate is represented rotor speed, and unit is r/min, and horizontal ordinate express time, unit are s; Figure 10 is the interior local measurement data of preceding 0.4s among Fig. 9, and wherein ordinate is represented rotor speed, and unit is r/min, and horizontal ordinate express time, unit are s.Rotor speed curve map of the present invention as can be seen from Figure is smoother, and the interference ratio of spiking is less, and the linear error of rotating speed is smaller.
In order to illustrate that measuring error of the present invention is smaller, to improve measuring accuracy, and can effectively reduce interference, noise, noiseproof feature to F/V converting unit of the present invention is tested, adopt DG1022 digital signal generator, DS5102MA oscillograph, DAQ1602 capture card, measurement range is 2.5KHz～3.5KHz, the DG1022 digital signal generator is the frequency sweep mode, and the frequency sweep frequency is 3000～3200Hz, and the signal frequency sweep time is 100ms.Observing noise with the DS5102MA oscillograph is that power supply causes 20KHz, about 6mVp-p, the 50ns spike, Figure 12 is 16 capture card data readbacks of DAQ1602, acquisition rate 10KHz/s, measuring method as can be seen from the figure of the present invention or device have effectively reduced interference, noise, have improved the tachometric survey precision.
Above-described embodiment of the present invention does not constitute the qualification to protection domain of the present invention.Any modification of being done within the spirit and principles in the present invention, be equal to and replace and improvement etc., all should be included within the claim protection domain of the present invention.
Claims (8)
1. the measuring method of a rotor speed of turbo generator is characterized in that, comprises step:
Change rotor speed into pulse electrical signal by sensor;
Described pulse electrical signal is pressed
Carry out the F/V conversion,
Wherein
The magnitude of voltage of the voltage signal after U (f) the expression conversion, the frequency values of f indicating impulse electric signal, f
1, f
2Be the frequency values of two predetermined pulse electrical signals, U
MaxBe scheduled voltage;
Voltage signal after the described F/V conversion is carried out digital-to-analog conversion;
Be converted to digital quantity by the voltage signal of data acquisition unit after with described digital-to-analog conversion.
2. the measuring method of rotor speed of turbo generator according to claim 1 is characterized in that: before described pulse electrical signal being carried out the F/V conversion, also comprise step:
Described pulse electrical signal is carried out differential operational handle, and the signal waveform after the differential operational processing is carried out shaping handle.
3. the measuring method of rotor speed of turbo generator according to claim 2 is characterized in that: before being converted to digital quantity by the voltage signal of data acquisition unit after with described digital-to-analog conversion, also comprise step:
Voltage signal after the described digital-to-analog conversion is carried out low-pass filtering treatment.
4. according to the measuring method of the described rotor speed of turbo generator of the arbitrary claim of claim 1 to 3, it is characterized in that:
f
1＝2500Hz，f
2＝3500Hz，U
max＝5V。
5. the measurement mechanism of a rotor speed of turbo generator, comprise sensor, F/V converting unit, D/A conversion unit and data acquisition unit, it is characterized in that: the output terminal of described sensor is connected by described F/V converting unit, D/A conversion unit and described data acquisition unit successively;
Described sensor outputs to described F/V converting unit after rotor speed is converted to pulse electrical signal, and described F/V converting unit is pressed described pulse electrical signal
Carry out the F/V conversion, wherein
The magnitude of voltage of the voltage signal after U (f) the expression conversion, the frequency values of f indicating impulse electric signal, f
1, f
2Be the frequency values of two predetermined pulse electrical signals, U
MaxBe scheduled voltage; The voltage signal of described D/A conversion unit after to described F/V conversion carries out outputing to described data acquisition unit after the digital-to-analog conversion, and the voltage signal of described data acquisition unit after with described digital-to-analog conversion is converted to digital quantity.
6. the measurement mechanism of rotor speed of turbo generator according to claim 5, it is characterized in that, also comprise: differential input block and signal reshape unit, the input end of described differential input block is connected with the output terminal of described sensor, and the output terminal of described differential input block is connected by the input end of described signal reshape unit with described F/V converting unit;
Described differential input block carries out outputing to described signal reshape unit after differential operational is handled to the pulse electrical signal of described sensor output, and the signal waveform after described signal reshape unit is handled this differential operational carries out outputing to described F/V converting unit after shaping is handled.
7. the measurement mechanism of rotor speed of turbo generator according to claim 6, it is characterized in that, also comprise: low-pass filter unit, be connected between the input end of the output terminal of described D/A conversion unit and described data acquisition unit, the voltage signal after the described D/A conversion unit digital-to-analog conversion is carried out outputing to described data acquisition unit after the low-pass filtering treatment.
8. according to the measurement mechanism of the described rotor speed of turbo generator of the arbitrary claim of claim 5 to 7, it is characterized in that:
f
1＝2500Hz，f
2＝3500Hz，U
max＝5V。
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009102144800A CN101762715B (en) | 2009-12-31 | 2009-12-31 | Method for measuring rotor speed of turbo generator and device thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009102144800A CN101762715B (en) | 2009-12-31 | 2009-12-31 | Method for measuring rotor speed of turbo generator and device thereof |
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|---|---|
| CN101762715A CN101762715A (en) | 2010-06-30 |
| CN101762715B true CN101762715B (en) | 2011-09-07 |
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| CN102004165B (en) * | 2010-09-13 | 2013-03-27 | 中国北车集团大连机车车辆有限公司 | Method for measuring instantaneous rotation speed of synchronous generator |
| CN102032867B (en) * | 2010-12-24 | 2012-07-18 | 哈尔滨工业大学 | Method for measuring relative rotation angle and relative rotation speed of two rotors of coaxial dual rotor motor and sensor for implementing same |
| CN102621345B (en) * | 2012-04-10 | 2013-08-14 | 西北工业大学 | Detection method and device of rotation speed of generator |
| CN105699683A (en) * | 2016-03-29 | 2016-06-22 | 杭州和利时自动化有限公司 | Steam turbine rotation speed measurement method and steam turbine rotation speed measurement system |
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Address after: 510080 Dongfeng East Road, Dongfeng, Guangdong, Guangzhou, Zhejiang Province, No. 8 Patentee after: Electric Power Research Institute of Guangdong Power Grid Co.,Ltd. Address before: 510600 No. 73 Meihua Road, Guangzhou, Guangdong, Yuexiu District Patentee before: ELECTRIC POWER RESEARCH INSTITUTE OF GUANGDONG POWER GRID Corp. |