CN109001504B - Generator frequency signal homologous device - Google Patents
Generator frequency signal homologous device Download PDFInfo
- Publication number
- CN109001504B CN109001504B CN201811118295.7A CN201811118295A CN109001504B CN 109001504 B CN109001504 B CN 109001504B CN 201811118295 A CN201811118295 A CN 201811118295A CN 109001504 B CN109001504 B CN 109001504B
- Authority
- CN
- China
- Prior art keywords
- signal
- frequency
- frequency signal
- generator
- module
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R1/00—Details of instruments or arrangements of the types included in groups G01R5/00 - G01R13/00 and G01R31/00
- G01R1/28—Provision in measuring instruments for reference values, e.g. standard voltage, standard waveform
Abstract
The invention discloses a generator frequency signal homologous device, which comprises a frequency signal conditioning module, a signal sampling and processing module, an input/output module and a human-computer interaction module, wherein the frequency signal conditioning module is used for processing a frequency signal; the generator output frequency signal is quickly and accurately measured and transmitted. The invention conditions sine waves into two paths of square wave signals with phase difference of 180 degrees, and combines the high-speed dual-channel input capturing capability of ARMF767, thereby shortening the frequency measurement response time by 10ms and ensuring the rapidity of the output frequency measurement of the generator set. The frequency measurement data processing algorithm adopts an improved filter coefficient self-adaptive first-order filter algorithm, so that the frequency measurement precision reaches 0.001Hz while the stability and the sensitivity of a frequency measurement result are ensured, and the accuracy of frequency measurement is ensured. The device has the advantages that the frequency measurement reliability is improved, the rapidness, the accuracy and the reliability of the output frequency measurement of the generator set can be greatly improved, and the economic and stable operation of the thermal power unit is ensured.
Description
Technical Field
The invention relates to the technical field of electric quantity measurement of generators, in particular to a generator frequency signal homologous device with high measurement precision and quick output response.
Background
Accurate measurement of the generator output voltage frequency is the basis for stable operation and control of the power system. At present, a large-scale assessment event often occurs to many thermal power generating units due to the shortage of primary frequency modulation response power grid load, wherein the asynchronization of frequency modulation load response, and the difference between a frequency signal adopted by power grid scheduling assessment and a frequency measurement signal adopted by thermal power generating unit adjustment are one of main reasons. The power grid requires the frequency modulation dead zone of the thermal power generating unit to be 2r/min, and the change trend of the power grid frequency signal adopted by power grid scheduling examination is theoretically ahead of the rotating speed signal of the thermal power generating unit. However, at present, a magneto-resistive probe is adopted for measuring the rotating speed of many thermal power generating units, the designed number of teeth is generally 60, and the problems of insufficient frequency modulation amplitude and delay frequently occur in the primary frequency modulation actual response of the thermal power generating units, so that the actual rotating speed feedback deviation is large and the delay time is long. While the frequency signals are often biased by interference. Therefore, a generator frequency signal homologous device with high measurement accuracy and fast output response is needed to solve the above-mentioned shortcomings.
At present, a single frequency measurement digital frequency transmitter is available in the market, but most of the transmitters adopt an A/D sampling circuit in a signal conditioning unit and calculate the frequency of a sampling signal by combining a corresponding data processing algorithm. The method is limited by the conversion precision, sampling rate and the like of the A/D converter, the frequency measurement precision is not high, the response time is long, and the homologous requirements of the generator frequency signal with high precision and fast response cannot be met.
Disclosure of Invention
The invention aims to provide a generator frequency signal homologous device with high measurement precision and high response speed. The device adopts a new method for rapidly and accurately measuring the frequency of the half-wave signal, not only can effectively filter power grid harmonic waves, but also has the characteristics of high frequency signal measurement precision (frequency measurement precision of 0.001Hz), short output response time (less than 40ms) and strong anti-interference capability. The generator output voltage frequency signal is measured and transmitted quickly and accurately.
In order to achieve the purpose, the invention adopts the following technical scheme:
a generator frequency signal homologous device comprises a frequency signal conditioning module, a signal sampling and processing module, an input/output module and a human-computer interaction module;
the frequency signal conditioning module comprises an input signal off-line switching circuit, a second-order low-pass filter circuit, a voltage amplitude limiting circuit, a zero-crossing hysteresis comparison circuit and an optical coupling isolation circuit, and is used for filtering higher harmonics of sinusoidal voltage signals output by the generator, conditioning the sinusoidal voltage signals into two paths of square wave signals with a phase difference of 180 degrees, and supplying the two paths of square wave signals to the signal sampling and processing module;
the signal sampling and processing module is combined with a high-speed dual-channel input capturing function of a main control chip STM32F767 and an improved filter coefficient self-adaptive first-order filter algorithm, so that the output frequency of the generator set is accurately and quickly measured;
the input and output module takes 0-3.3V voltage output by a main control chip STM32F767 frequency signal as an input signal and sends the input signal to the module through a transient suppression diode, and correspondingly outputs a corresponding 4-20mA current signal for an automatic generator adjusting system and a dispatching system, so that an accurate and reliable frequency measurement result is provided for power plant frequency modulation;
the man-machine interaction module is used for information exchange between the device and a user, and comprises measurement result display, system parameter setting and measurement calibration.
As a further scheme of the present invention, the input signal disconnection switching circuit of the frequency signal conditioning module includes a signal isolation circuit, two single-pole double-throw relays and a corresponding driving circuit, the single-pole double-throw relays are respectively connected to two different generator terminal voltages, and one of the signals is sent to the second-order low-pass filter circuit by a control signal sent by the main control chip, so as to implement the function of frequency input signal disconnection switching.
As a further scheme of the invention, the second-order low-pass filter circuit of the frequency signal conditioning module is used for filtering out higher harmonic interference in the input signal.
As a further scheme of the invention, the voltage amplitude limiting circuit and the zero-crossing hysteresis comparison circuit of the frequency signal conditioning module convert the input sinusoidal voltage signal into two paths of square wave signals with phase difference of 180 degrees, and the period and the zero-crossing point of the output square wave signal are equal to those of the input sinusoidal voltage signal in high precision.
As a further scheme of the invention, the optical coupling isolation circuit of the frequency signal conditioning module isolates and amplifies the square wave signal output by the zero-crossing hysteresis comparison circuit and outputs two paths of high and low level signals which can be captured by the main control chip STM32F 767.
As a further scheme of the invention, the frequency measurement data processing algorithm in the signal sampling and processing module adopts an improved filter coefficient self-adaptive first-order filter algorithm, and can automatically calculate the sensitivity coefficient according to the previous 3 times of historical data and the current data.
As a further aspect of the present invention, the signal input and output ends of the input and output module have an electromagnetic isolation function.
As a further scheme of the invention, the man-machine interaction module consists of a TFT liquid crystal color screen, an indicator light and a key.
A generator frequency signal homologous device, an improved filter coefficient self-adaptive first-order filter algorithm, before adjustment, the following judgment is carried out:
a) whether the previous 3 changes of the current data face the same direction or not;
b) whether the previous 3 changes of the current data are fast or not;
the improved filter coefficient self-adaptive first-order filtering algorithm realizes that:
a) when data change rapidly, the filtering result can follow up in time (sensitivity is first); and the faster the data changes, the higher the sensitivity should be;
b) the filtering results can tend to be smooth (smoothness takes precedence) as the data tends to stabilize and oscillate up and down at a fixed point.
The invention has the beneficial effects that: (1) the device provided by the invention is provided with a single-phase voltage waveform conditioning circuit, a second-order low-pass filter circuit for effectively filtering power grid harmonics, a voltage amplitude limiting circuit and a zero-crossing hysteresis comparison circuit, and is used for conditioning sine waves into two paths of square signals with a phase difference of 180 degrees, and combining the high-speed double-channel input capturing capability of STM32F767, so that the frequency measurement response time is shortened by 10ms, and the rapidity of measuring the output frequency of the generator set is ensured.
(2) The frequency measurement data processing algorithm of the device adopts an improved filter coefficient self-adaptive first-order filter algorithm, ensures the stability and sensitivity of a frequency measurement result, ensures the frequency measurement precision to reach 0.001Hz, ensures the accuracy of frequency measurement, and ensures that the frequency transmission output has very high industrial practical value.
(3) The device has the function of switching the frequency input signal in case of disconnection, automatically identifies, judges and switches the frequency input signal to another path of input signal after the frequency input signal is disconnected, and simultaneously sends out the input signal disconnection alarm information, thereby improving the reliability of frequency measurement of the device.
Drawings
FIG. 1 is a structural diagram of a generator frequency signal homologous device according to the present invention;
FIG. 2 is a circuit diagram of a single phase voltage waveform conditioning circuit of the present invention;
FIG. 3 is a logic diagram for determining whether a frequency signal is disconnected according to the present invention;
fig. 4 is a flow chart of a frequency measurement data processing algorithm of the present invention.
Detailed Description
The technical solution in the embodiments of the present invention will be clearly and completely explained below with reference to the drawings in the embodiments of the present invention.
As shown in fig. 1-2, a generator frequency signal homologous device includes a frequency signal conditioning module, a signal sampling and processing module, an input/output module, and a human-computer interaction module;
the frequency signal conditioning module comprises an input signal off-line switching circuit, a second-order low-pass filter circuit, a voltage amplitude limiting circuit, a zero-crossing hysteresis comparison circuit and an optical coupling isolation circuit, and is used for filtering higher harmonics of sinusoidal voltage signals output by the generator, conditioning the sinusoidal voltage signals into two paths of square wave signals with a phase difference of 180 degrees, and supplying the two paths of square wave signals to the signal sampling and processing module;
the signal sampling and processing module is combined with a high-speed dual-channel input capturing function of a main control chip STM32F767 and an improved filter coefficient self-adaptive first-order filter algorithm, so that the output frequency of the generator set is accurately and quickly measured;
the input and output module takes 0-3.3V voltage output by a main control chip STM32F767 frequency signal as an input signal and sends the input signal to the module through a transient suppression diode, and correspondingly outputs a corresponding 4-20mA current signal for an automatic generator adjusting system and a dispatching system, so that an accurate and reliable frequency measurement result is provided for power plant frequency modulation;
the man-machine interaction module is used for information exchange between the device and a user, and comprises measurement result display, system parameter setting and measurement calibration.
The input signal disconnection switching circuit of the frequency signal conditioning module comprises a signal isolation circuit, two single-pole double-throw relays and corresponding driving circuits, the single-pole double-throw relays are respectively connected to two different generator terminal voltages, one signal is sent to a second-order low-pass filter circuit through a control signal sent by a main control chip, and the function of frequency input signal disconnection switching is achieved. The reliability of the frequency measurement of the device is improved.
And the second-order low-pass filter circuit of the frequency signal conditioning module is used for filtering out higher harmonic interference in the input signal. The voltage amplitude limiting circuit and the zero-crossing hysteresis comparison circuit of the frequency signal conditioning module convert the input sinusoidal voltage signal into two paths of square wave signals with phase difference of 180 degrees, and the period and the zero-crossing point of the output square wave signal are equal to those of the input sinusoidal voltage signal in high precision.
The optical coupling isolation circuit of the frequency signal conditioning module isolates and amplifies the square wave signal output by the zero-crossing hysteresis comparison circuit and outputs two paths of high and low level signals which can be captured by the main control chip STM32F 767.
The frequency measurement data processing algorithm in the signal sampling and processing module adopts an improved filter coefficient self-adaptive first-order filter algorithm, and can automatically calculate the sensitivity coefficient according to the previous 3 times of historical data and the current data. The frequency signal output has high sensitivity when the frequency changes rapidly, and has good stability when the frequency fluctuates in a small range, so that the accuracy of frequency measurement is ensured, and the frequency measurement precision of the device reaches 0.001 Hz.
The signal input and output ends of the input and output module have electromagnetic isolation function. The man-machine interaction module is composed of a TFT liquid crystal color screen, an indicator light and a key.
As shown in fig. 3, the main control chip implements the function of switching the frequency input signal off through the input generator terminal voltage signal, so that the device can automatically identify, jump and alarm after one input signal fails, and can still correctly output the frequency measurement signal, thereby improving the reliability of the frequency measurement of the device.
As shown in fig. 4, the frequency measurement data processing algorithm of the present invention is a flow chart, and combines with the actual engineering requirements of the device for frequency measurement signal processing, and adopts an improved filter coefficient adaptive first-order filter algorithm, so that the sensitivity coefficient can be automatically calculated according to the previous 3 historical data and the current data. Before the adjustment, the following judgment is carried out:
a) whether the previous 3 changes of the current data face the same direction or not;
b) whether the previous 3 changes of the current data are fast or not;
the improved filter coefficient self-adaptive first-order filtering algorithm realizes that:
a) when data change rapidly, the filtering result can follow up in time (sensitivity is first); and the faster the data changes, the higher the sensitivity should be;
b) the filtering results can tend to be smooth (smoothness takes precedence) as the data tends to stabilize and oscillate up and down at a fixed point.
Therefore, the coefficient self-adaptive first-order filtering algorithm ensures that the frequency signal output has higher sensitivity when the frequency changes rapidly and has better stability when the frequency fluctuates in a small range. Practice proves that the frequency measurement precision of the algorithm reaches 0.001Hz, the accuracy of frequency measurement is guaranteed, and the algorithm has very high industrial practical value and innovation.
In summary, the generator frequency signal homology device of the present invention firstly sends two different generator terminal voltages to the input signal disconnection switching circuit, and sends one signal as output to the second-order low-pass filter circuit. After the harmonics are filtered, the fundamental wave component is sent to a voltage amplitude limiting circuit and a dual-channel zero-crossing hysteresis comparison circuit, and two paths of square wave signals with phase difference of 180 degrees are output. And the two paths of square signals are amplified and then sent into a high-speed optical coupling isolation circuit, and high and low level signals which can be identified by STM32F7 are output. Through the high-speed dual-channel input capturing and hardware filtering functions of the main control chip ARMF767, the periods of two paths of square wave signals with the phase difference of 180 degrees are respectively calculated, and frequency signal measurement data are output at the interval of 10 ms. The frequency measurement data is filtered by an improved filter coefficient self-adaptive first-order filter algorithm to obtain a frequency signal measurement result. The input and output module converts the frequency signal measurement result into a corresponding 4-20mA current signal for the automatic generator adjusting system to use, and provides an accurate and reliable frequency measurement result for power plant frequency modulation. The man-machine interaction module is used for displaying information exchange between devices such as measurement results and the like and a user.
The foregoing is a preferred embodiment of the present invention, and it will be apparent to those skilled in the art that variations, modifications, substitutions and alterations can be made in the embodiment without departing from the principles and spirit of the invention.
Claims (8)
1. A generator frequency signal homologous device is characterized by comprising a frequency signal conditioning module, a signal sampling and processing module, an input/output module and a man-machine interaction module;
the frequency signal conditioning module comprises an input signal off-line switching circuit, a second-order low-pass filter circuit, a voltage amplitude limiting circuit, a zero-crossing hysteresis comparison circuit and an optical coupling isolation circuit, and is used for filtering higher harmonics of sinusoidal voltage signals output by the generator, conditioning the sinusoidal voltage signals into two paths of square wave signals with a phase difference of 180 degrees, and supplying the two paths of square wave signals to the signal sampling and processing module;
the signal sampling and processing module is combined with a high-speed dual-channel input capturing function of a main control chip STM32F767 and an improved filter coefficient self-adaptive first-order filter algorithm, so that the output frequency of the generator set is accurately and quickly measured;
the input and output module takes 0-3.3V voltage output by a main control chip STM32F767 frequency signal as an input signal and sends the input signal to the module through a transient suppression diode, and correspondingly outputs a corresponding 4-20mA current signal for an automatic generator adjusting system and a dispatching system, so that an accurate and reliable frequency measurement result is provided for power plant frequency modulation;
the man-machine interaction module is used for information exchange between the device and a user, and comprises measurement result display, system parameter setting and measurement calibration.
2. The generator frequency signal homology device according to claim 1, wherein the input signal disconnection switching circuit of the frequency signal conditioning module comprises a signal isolation circuit, two single-pole double-throw relays and a corresponding driving circuit, the single-pole double-throw relays are respectively connected to two different generator terminal voltages, and one signal is sent to the second-order low-pass filter circuit through a control signal sent by the main control chip, so that the frequency input signal disconnection switching function is realized.
3. The generator frequency signal homology device according to claim 1, wherein the second-order low-pass filter circuit of the frequency signal conditioning module is configured to filter out higher harmonic interference in the input signal.
4. The generator frequency signal homology device according to claim 1, wherein the voltage amplitude limiting circuit and the zero-crossing hysteresis comparing circuit of the frequency signal conditioning module convert the input sinusoidal voltage signal into two square wave signals with a phase difference of 180 degrees, and the period and zero-crossing point of the output square wave signal are equal to those of the input sinusoidal voltage signal with high precision.
5. The generator frequency signal homology device according to claim 1, wherein an optical coupling isolation circuit of the frequency signal conditioning module isolates and amplifies a square wave signal output by a zero-crossing hysteresis comparison circuit, and outputs two paths of high and low level signals which can be captured by a main control chip STM32F 767.
6. The generator frequency signal homology device according to claim 1, wherein the frequency measurement data processing algorithm in the signal sampling and processing module adopts a modified filter coefficient adaptive first-order filter algorithm, and the sensitivity coefficient can be automatically calculated according to the previous 3 historical data and the current data.
7. The generator frequency signal homology device according to claim 1, wherein the signal input and output ends of the input and output module have electromagnetic isolation functions.
8. The generator frequency signal homology device according to claim 1, wherein the human-computer interaction module comprises a TFT liquid crystal color screen, an indicator light and a key.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811118295.7A CN109001504B (en) | 2018-09-26 | 2018-09-26 | Generator frequency signal homologous device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811118295.7A CN109001504B (en) | 2018-09-26 | 2018-09-26 | Generator frequency signal homologous device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109001504A CN109001504A (en) | 2018-12-14 |
| CN109001504B true CN109001504B (en) | 2020-12-18 |
Family
ID=64589204
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811118295.7A Active CN109001504B (en) | 2018-09-26 | 2018-09-26 | Generator frequency signal homologous device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109001504B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111579866A (en) * | 2020-05-10 | 2020-08-25 | 哈船光电(武汉)有限公司 | Signal frequency testing method and device |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2446299Y (en) * | 2000-09-28 | 2001-09-05 | 南海鹏 | Frequency detector of hydroturbine speed governor |
| US6944569B2 (en) * | 2003-04-01 | 2005-09-13 | Fluke Precision Measurement Ltd. | Method and apparatus for generating an electronic test signal |
| CN102155984A (en) * | 2010-12-30 | 2011-08-17 | 北京四方继保自动化股份有限公司 | General vibration signal measuring system of fan |
| CN104391176A (en) * | 2014-12-13 | 2015-03-04 | 华北电力大学 | Software and hardware frequency measurement circuit compatible with electric power system signals |
| CN108037359A (en) * | 2017-11-21 | 2018-05-15 | 北京智芯微电子科技有限公司 | A kind of grid frequency measurement circuit for eliminating flickering and m-Acetyl chlorophosphonazo interference |
-
2018
- 2018-09-26 CN CN201811118295.7A patent/CN109001504B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2446299Y (en) * | 2000-09-28 | 2001-09-05 | 南海鹏 | Frequency detector of hydroturbine speed governor |
| US6944569B2 (en) * | 2003-04-01 | 2005-09-13 | Fluke Precision Measurement Ltd. | Method and apparatus for generating an electronic test signal |
| CN102155984A (en) * | 2010-12-30 | 2011-08-17 | 北京四方继保自动化股份有限公司 | General vibration signal measuring system of fan |
| CN104391176A (en) * | 2014-12-13 | 2015-03-04 | 华北电力大学 | Software and hardware frequency measurement circuit compatible with electric power system signals |
| CN108037359A (en) * | 2017-11-21 | 2018-05-15 | 北京智芯微电子科技有限公司 | A kind of grid frequency measurement circuit for eliminating flickering and m-Acetyl chlorophosphonazo interference |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109001504A (en) | 2018-12-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109001580B (en) | Intelligent electric quantity transmission device of generator | |
| CN101881790A (en) | Intelligent electric power parameter tester | |
| CN109001504B (en) | Generator frequency signal homologous device | |
| CN103248058B (en) | A kind of Magnetically-controlreactor reactor control system | |
| CN110058100B (en) | Delay measurement method, device and system of direct current transmission system | |
| CN101350519A (en) | Real-time synchronization equipment for protecting optical fibre longitudinal difference | |
| CN104993576A (en) | Double power supply automatic change-over switch controller and method | |
| CN105425030A (en) | Three-phase digital electric quantity transmitter | |
| CN104914296A (en) | Multifunctional clamp meter | |
| Jebroni et al. | Remote calibration system of a smart electrical energy meter. | |
| CN105606147B (en) | A kind of portable trans calibrator | |
| CN106059547B (en) | Dead-zone compensation method and device in a kind of PWM | |
| CN210775648U (en) | Three-phase electric energy meter system | |
| CN111474414A (en) | Link delay testing method and system of flexible direct current control system | |
| CN202815644U (en) | High-power full-automatic intelligent alternative current (AC) voltage stabilized power supply | |
| CN200941550Y (en) | Motor protector | |
| CN213581078U (en) | Alternating current-direct current hybrid universal intelligent electric meter | |
| CN205561885U (en) | Portable changer check gauge | |
| CN212931520U (en) | Electromagnetic flowmeter | |
| CN213875844U (en) | Auxiliary system for measuring low-frequency output impedance of distributed power supply in microgrid | |
| CN109041311B (en) | Self-adaptive digital phase-locked controller | |
| CN205304252U (en) | Automatic switching protection device for compensation cabinet divides into groups | |
| CN106093842A (en) | three phase harmonic standard electric energy meter | |
| CN101097453B (en) | Constant-current controller capable of communicating | |
| CN202886461U (en) | An AC voltage detecting device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |