CN102468897A - Digital signal synchronization method - Google Patents
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Abstract
The invention discloses a digital signal synchronization method, which comprises the following steps that: a first device samples analog quantity signals at an XkHz sampling rate through an AD chip of the first device, and converts the analog quantity signals into a first path of digital quantity signals, and a second device sends messages to the first device through an IEC60044-8 or IEC61850-9-2 point-to-point protocol, and the first device analyzes the messages to obtain a second path of digital quantity signals; the sampling moment when the first device samples the voltage analog quantity signals at the XkHz sampling rate through the AD chip is endowed with a time mark t1, and the moment when the first device receives the second path of digital signals through the IEC60044-8 or IEC61850-9-2point-to-point protocol is endowed with a time mark t2, so that values and time marks of the two paths of digital signals are obtained; and through a Lagrange's interpolation algorithm, the two paths of signals are respectively interpolated to a value corresponding to a time mark t at the interruption frequency of MkHz and are synchronized.
Description
Technical field
The present invention relates at signal synchronizing method, especially digital transformer substation digital signal method for synchronous relates to the work of electronic mutual inductor precision checking.
Background technology
Electronic mutual inductor in the digital transformer substation with respect to the instrument transformer of routine because its distinctive advantage; Such as, insulation is simple, no ferro resonance and magnetic saturation problem, Keep Clear-High Voltage, certainty of measurement high for no secondary coil open circuit, dynamic range is big, do not have because of oil-filled and potential danger such as inflammable, explosive, volume little, in light weight etc.Along with electric power system to big capacity, the voltage levels direction develops, thereby electronic mutual inductor is widely used.Along with the development of digital transformer substation, because electronic mutual inductor output is digital interface, traditional mutual-inductor tester and method of calibration have seemed unable to do what one wishes to checking electronic type transformers.And the precision of whole protecting, observing and controlling, kilowatt-hour meter, oscillograph etc. is different with conventional transformer station, and it depends on the precision of electronic mutual inductor fully.Therefore just need special-purpose testing tool to accomplish the accuracy test work of electronic mutual inductor, to understand the running status of whole transformer station.
In present digital transformer substation, exist the stipulations of these three kinds of national standards of IEC60044-8, IEC61850-9-1 and IEC61850-9-2 (point-to-point or networking).In the research of present stage, electronic transducer calibration instrument is basic only supports wherein one, and this has just caused to different stipulations need use different checking electronic type transformers devices.So the signal that how can these three kinds of stipulations be sent and the analog signal of AD chip sampling are the problem that needs solve synchronously.
In addition for occurring adopting dissimilar instrument transformers in the transformer station; Such as traditional electromagnetic transformer; Electronic mutual inductor; The optics instrument transformer receives electric current, voltage signal from dissimilar instrument transformers for the bus differential protecting device, has plenty of current signal and directly inserts; Pass through IEC60044-8, IEC61850-9-1 or the IEC61850-9-2 stipulations that have receive the signal from merge cells, and so how carrying out these various signals also is synchronously the problem that realizes that bus differential protection must solve.
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Summary of the invention
The object of the invention: the method for synchronous that the digital signal of using different communications protocol transmission in a kind of digital signal method for synchronous, the especially digital transformer substation is provided.Provide through the analog signal of these three digital signals that international standard transmitted of IEC60044-8, IEC61850-9-1 and IEC61850-9-2 (point-to-point or networking) and the sampling of AD chip and carry out synchronous method.
Technical scheme of the present invention: the digital signal method for synchronous to the message that different communication protocols is sent, has following two kinds of digital signal synchronization processing methods:
One, first via digital signal amount by first device through its AD chip with XkHz sample rate sampled analog amount signal and convert digital quantity signal to; The second road digital quantity signal is obtained through IEC60044-8 or IEC61850-9-2 (point-to-point) stipulations and after sending to the message of first device and passing through parsing by second device, it is characterized in that:
Give markers t1 via the AD chip with the sampling instant of XkHz sample rate sampled voltage analog signals with first device; Give markers t2 with the moment that first device receives the two paths of digital signals that receives through IEC60044-8 or IEC61850-9-2 (point-to-point) stipulations, so just obtained the numerical value and the markers of this two ways of digital signals respectively;
Through the Lagrange's interpolation algorithm, this two paths of signals is interpolated into the pairing numerical value of markers t that interruption frequency is MkHz respectively, two paths of signals is carried out synchronously:
The formula of Lagrange's interpolation algorithm is following:
is the interpolation calculation t value corresponding constantly of coming out.
Two, first via digital signal amount by first device through its AD chip with XkHz sample rate sampled analog amount signal and convert digital quantity signal to; The second road digital quantity signal sends to first device through IEC61850-9-1 or IEC61850-9-2 (networking) stipulations by second device after with XkHz sample rate sampled analog amount signal; And obtain after resolving by first device; First device and second device all receive the synchronizing signal from first device output, it is characterized in that:
First device will be given the counting of markers t1 and corresponding counter smpcnt1 via the AD chip with the sampling instant of XkHz sample rate sampled voltage analog signals; And first device receives the counting that contains the sampling instant counter smpcnt2 of second device in the Frame of digital signal from second device, and obtains sampling instant t2 according to this counter; The numerical value and the markers of this two ways of digital signals have been obtained so respectively.Said first and second device all is signal receiving/transmission devices of digital transformer substation or its sensing device.
The scope of X from individual position to hundred all can, not special the qualification.Interruption frequency generally is lower than X.
Lagrange's interpolation algorithm shown in the through type 1 is interpolated into the pairing numerical value of markers t that interruption frequency is MKHz respectively with this two paths of signals.
Beneficial effect of the present invention: adopt digital signal method for synchronous of the present invention, can the signal of the communication protocol of three kinds of international standards of IEC60044-8, IEC61850-9-1 and IEC61850-9-2 (point-to-point or networking) and the analog signal of AD chip sampling be carried out synchronously.
Description of drawings
The system construction figure of Fig. 1 electronic mutual inductor precision checking appearance
Device structure connection layout when Fig. 2 tries instrument transformer precision checking appearance verification electronic current mutual inductor for the electronics that adopts this method
Device structure connection layout when Fig. 3 tries instrument transformer precision checking appearance verification electronic type voltage transformer for the electronics that adopts this method.
Embodiment
Think example with the electronic mutual inductor precision checking, provide concrete implementation method.First device just is meant electronic mutual inductor precision checking appearance; Second device just is meant the electronic mutual inductor merge cells.
One, the structure of electronic mutual inductor precision checking appearance
Electronic mutual inductor precision checking appearance as shown in Figure 1 comprises power insert, CPU card and two blocks of DSP plug-in units:
DSP plug-in unit 1 is connected through the input of two pins on the DB terminal and external perimysium reference tunnels analogy small signal; Be connected to AD conversion chip input through operational amplifier then; Again AD conversion chip output is connected to the digital input end of dsp chip; Digital signal is connected to field programmable gate array chip FPGA through fiber optical transceiver simultaneously, and FPGA is connected to dsp chip after it is decoded;
The fiber optical transceiver output of the fiber optic Ethernet mouth of DSP plug-in unit 2 is connected to the high accuracy PHY chip, the output of high accuracy physical chip is connected to the mac controller of dsp chip again, and FPGA connects DSP plug-in unit 1 through speed serial communication bus;
The fpga chip of CPU card connects DSP plug-in unit 1 and DSP plug-in unit 2 through speed serial communication bus; Output after the data decode is connected to cpu chip; Cpu chip is connected to liquid crystal through 485 communication ports; The backstage is through netting twine access network based on ethernet controller simultaneously, and ethernet controller is connected to cpu chip with the message of resolving.
Two, the method that adopts electronic transducer calibration instrument as shown in Figure 1 that the electronic mutual inductor precision is tested:
1, this tester is when the current precision test of carrying out electronic current mutual inductor:
As shown in Figure 2, the Primary Conductor that feeds electric current is simultaneously through precision current instrument transformer
and the mutual current sensors ECT of tested electronic current.The precision current instrument transformer produces the analog quantity input interface entering AD sampling A of small voltage signal V1 through DSP plug-in unit 1 through current-to-voltage converter.Behind the process remote end module and merge cells of the mutual current transformer of tested electronic type, send digital signal through optical fiber and insert this tester DSP plug-in unit 1 or DSP plug-in unit 2.If the signal that merge cells sends is supported the IEC60044-8 stipulations, then this digital signal inserts the optical fiber interface of DSP plug-in unit 1; , merge cells inserts the optical fiber interface of the DSP plug-in unit 2 of electronic mutual inductor precision checking appearance if supporting IEC61850-9-1 or IEC61850-9-2 (point-to-point or networking) stipulations.After tester is received two paths of signals, just can carry out synchronous computing in real time.
2, this tester is when the voltage accuracy test of carrying out electronic type voltage transformer:
As shown in Figure 3, the EVT last (comprising on resistance, inductance, the capacitance partial pressure ring) that voltage is added in accurate voltage mutual inductor and tested electronic mutual inductor simultaneously falls.Accurate voltage mutual inductor produces the analog quantity input interface entering AD sampling A that small voltage signal V1 directly passes through the DSP plug-in unit 1 of electronic mutual inductor precision checking appearance through inductive voltage divider; Behind tested electronic type voltage transformer process remote end module and the merge cells, send digital signal through optical fiber and insert this tester DSP plug-in unit 1 or DSP plug-in unit 2.If the signal that merge cells sends is supported the IEC60044-8 stipulations, then this digital signal inserts the optical fiber interface of DSP plug-in unit 1; , merge cells inserts the optical fiber interface of DSP plug-in unit 2 if supporting IEC61850-9-1 or IEC61850-9-2 (point-to-point or networking) stipulations.After tester is received two paths of signals, just can carry out synchronous computing in real time.
Three, the synchronous method of two ways of digital signals of the present invention's employing
Electronic mutual inductor precision checking appearance receive the small voltage signal and via the AD chip with 4KHz sample rate sampled voltage analog signals and convert digital quantity signal to; Receive message through communication protocol simultaneously; Form the second road digital quantity signal through decoding back, need carry out carrying out accuracy computation after synchronous this two ways of digital signals.
Suppose that it is in the 50Hz electric power system that electronic mutual inductor operates in power frequency, electronic mutual inductor school precision is tested appearance and is converted into digital signal with the sample rate of 4kHz through A/D standard for manual sampling source voltage V1, and gives markers t1 with sampling instant; Receive the digital signal that tested electronic mutual inductor merge cells is come simultaneously, and the moment that will receive this Frame is given markers t2.Tester has just obtained the numerical value and the markers of this two ways of digital signals respectively like this.Then, through the Lagrange's interpolation algorithm, the pairing numerical value of markers t that this two paths of signals is interpolated into 1.2kHz respectively carries out synchronously.Tester calculates in real time according to the numerical value of the 1.2kHz that this interpolation obtains, compares the ratio and the angular difference of this two paths of signals, and comes out through liquid crystal display.The formula of Lagrange's interpolation algorithm is following:
Wherein:
is continuous 3 points of AD sampling or optical fiber acceptance;
Two interruptions need be set control sample rate 4kHz and interpolation interruption frequency 1.2kHz respectively.
If 1 electronic mutual inductor precision checking appearance receives message through IEC60044-8 or IEC61850-9-2 (point-to-point) stipulations and after decoding, forms the digital signal amount, interpolation is the obtaining value method of t2 constantly:
To give markers t1 with the sampling instant of 4KHz sample rate sampled voltage analog signals via the AD chip; The moment that will receive the digital signal 2 that receives through IEC60044-8 or IEC61850-9-2 (point-to-point) stipulations is given markers t2; Tester has just obtained the numerical value and the markers of this two ways of digital signals respectively like this, takes above-mentioned formula 1 that this two paths of signals is interpolated into the pairing numerical value of markers t that interruption frequency is 1.2kHz respectively then.
If 2 electronic mutual inductor precision checking appearance receive message through IEC61850-9-1 or IEC61850-9-2 (networking) stipulations and after decoding, form the digital signal amount, interpolation is the obtaining value method of t2 constantly:
Attention: the electronic mutual inductor merge cells sends to electronic mutual inductor precision checking appearance with the sample rate of 4kHz through IEC61850-9-1 or IEC61850-9-2 (networking) stipulations in this case.
To give markers t1 and corresponding counter smpcnt1 with the sampling instant of 4kHz sample rate sampled voltage analog signals via the AD chip; And first device receives the counting that contains the sampling instant counter smpcnt2 of second device in the digital data frames of digital signal from second device, and obtains sampling instant t2 according to this counter; The numerical value and the markers of this two ways of digital signals have been obtained so respectively.
Take above-mentioned formula 1 that this two paths of signals is interpolated into the pairing numerical value of markers t that interruption frequency is 1.2kHz respectively then.
Please note: in this case, the merge cells of electronic mutual inductor and electronic mutual inductor precision checking appearance all must receive the synchronizing signal from the unified clock source.
Claims (4)
1. digital signal method for synchronous; First via digital signal amount by first device through its AD chip with XkHz sample rate sampled analog amount signal and convert digital quantity signal to; The second road digital quantity signal sends to the message of first device by second device through IEC60044-8 or the point-to-point stipulations of IEC61850-9-2 and after resolving, obtains, and it is characterized in that:
Give markers t1 via the AD chip with the sampling instant of XkHz sample rate sampled voltage analog signals with first device; Give markers t2 with the moment that first device receives the two paths of digital signals that receives through IEC60044-8 or the point-to-point stipulations of IEC61850-9-2, so just obtained the numerical value and the markers of this two ways of digital signals respectively;
Through the Lagrange's interpolation algorithm, this two paths of signals is interpolated into the pairing numerical value of markers t that interruption frequency is MkHz respectively, two paths of signals is carried out synchronously:
The formula of Lagrange's interpolation algorithm is following:
Wherein:
is continuous 3 points of said any way word signal;
2. digital signal method for synchronous; First via digital signal amount by first device through its AD chip with XkHz sample rate sampled analog amount signal and convert digital quantity signal to; The second road digital quantity signal sends to first device through IEC61850-9-1 or IEC61850-9-2 networking stipulations by second device after with XkHz sample rate sampled analog amount signal; And obtain after resolving by first device; First device and second device all receive the synchronizing signal from first device output, it is characterized in that:
First device will be given the counting of markers t1 and corresponding counter smpcnt1 via the AD chip with the sampling instant of XkHz sample rate sampled voltage analog signals; And first device receives the counting that contains the sampling instant counter smpcnt2 of second device in the Frame of digital signal from second device, and obtains sampling instant t2 according to this counter; The numerical value and the markers of this two ways of digital signals have been obtained so respectively;
Lagrange's interpolation algorithm shown in the through type 1 is interpolated into the pairing numerical value of markers t that interruption frequency is MkHz respectively with this two paths of signals.
3. digital signal method for synchronous as claimed in claim 2 is characterized in that: first device output synchronizing signal is given second device.
4. digital signal method for synchronous as claimed in claim 1 is characterized in that: the first and second two interruptions are set control sample rate XkHz and interpolation interruption frequency MkHz respectively.
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Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102904663A (en) * | 2012-10-22 | 2013-01-30 | 华自科技股份有限公司 | IEC 61850-9-2 standard-based cross-interval point-to-point communication synchronous-sampling method |
| CN102944860A (en) * | 2012-10-31 | 2013-02-27 | 江苏省电力公司电力科学研究院 | Method and device for comparing running errors of optical current transformer and electromagnetic current transformer in real time |
| CN103324603A (en) * | 2013-06-07 | 2013-09-25 | 山东山大电力技术有限公司 | Interpolation transformation method with various sampling rates |
| CN103592616A (en) * | 2013-11-14 | 2014-02-19 | 江苏林洋电子股份有限公司 | Independent full-automatic concurrent single-point modification method |
| CN103763085A (en) * | 2014-01-17 | 2014-04-30 | 南京信息职业技术学院 | Method and device for high-speed acquisition and combination of multi-path data |
| CN108010301A (en) * | 2017-11-06 | 2018-05-08 | 国家电网公司 | A kind of digital transformer substation electric energy quality monitoring system and method |
| CN110535551A (en) * | 2019-09-26 | 2019-12-03 | 南京国电南自电网自动化有限公司 | The synchronous method and system of failure wave-recording sampled data in a kind of electric system |
| CN116338558A (en) * | 2023-05-31 | 2023-06-27 | 国网福建省电力有限公司 | DC voltage broadband digital quantity standard device and use method thereof |
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| US20020136316A1 (en) * | 1999-12-14 | 2002-09-26 | Bert Winkler | Method and system for detecting an digitally transmitting analog output measured quantities of a number of transducers |
| CN201589856U (en) * | 2009-12-11 | 2010-09-22 | 南京南瑞继保电气有限公司 | Precision checking instrument for electronic transformer |
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Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020136316A1 (en) * | 1999-12-14 | 2002-09-26 | Bert Winkler | Method and system for detecting an digitally transmitting analog output measured quantities of a number of transducers |
| CN201589856U (en) * | 2009-12-11 | 2010-09-22 | 南京南瑞继保电气有限公司 | Precision checking instrument for electronic transformer |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102904663A (en) * | 2012-10-22 | 2013-01-30 | 华自科技股份有限公司 | IEC 61850-9-2 standard-based cross-interval point-to-point communication synchronous-sampling method |
| CN102944860A (en) * | 2012-10-31 | 2013-02-27 | 江苏省电力公司电力科学研究院 | Method and device for comparing running errors of optical current transformer and electromagnetic current transformer in real time |
| CN103324603A (en) * | 2013-06-07 | 2013-09-25 | 山东山大电力技术有限公司 | Interpolation transformation method with various sampling rates |
| CN103324603B (en) * | 2013-06-07 | 2016-03-30 | 山东山大电力技术有限公司 | A kind of Interpolating transform method of different sampling rate |
| CN103592616A (en) * | 2013-11-14 | 2014-02-19 | 江苏林洋电子股份有限公司 | Independent full-automatic concurrent single-point modification method |
| CN103592616B (en) * | 2013-11-14 | 2016-05-04 | 江苏林洋能源股份有限公司 | One can the full-automatic concurrent type frog single-point of autonomous type modification method |
| CN103763085A (en) * | 2014-01-17 | 2014-04-30 | 南京信息职业技术学院 | Method and device for high-speed acquisition and combination of multi-path data |
| CN103763085B (en) * | 2014-01-17 | 2016-08-17 | 南京信息职业技术学院 | Method and device for high-speed acquisition and combination of multi-path data |
| CN108010301A (en) * | 2017-11-06 | 2018-05-08 | 国家电网公司 | A kind of digital transformer substation electric energy quality monitoring system and method |
| CN110535551A (en) * | 2019-09-26 | 2019-12-03 | 南京国电南自电网自动化有限公司 | The synchronous method and system of failure wave-recording sampled data in a kind of electric system |
| CN116338558A (en) * | 2023-05-31 | 2023-06-27 | 国网福建省电力有限公司 | DC voltage broadband digital quantity standard device and use method thereof |
| CN116338558B (en) * | 2023-05-31 | 2023-09-22 | 国网福建省电力有限公司 | DC voltage broadband digital quantity standard device and use method thereof |
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