CN101726658A - Single-channel time-sharing multiplexing sampling method and sampling circuit thereof - Google Patents
Single-channel time-sharing multiplexing sampling method and sampling circuit thereof Download PDFInfo
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Abstract
The invention discloses a single-channel time-sharing multiplexing sampling method, which comprises the following steps that: 1, single-path primary signals are converted into single-channel signals through an analog switch controlled by a single chip; 2, a single-channel signal output end is connected with an amplification signal of an amplifying circuit; 3, the output end of the amplifying circuit is connected with a filtered high-frequency signal of a filter circuit; and 4, the output end of the filter circuit is connected with the single chip with A/D to sample and calculate the sampling signals. The method is implemented by means of a single-channel time-sharing multiplexing sampling circuit; and the sampling circuit consists of the analog switch, a programmable amplifying circuit, an anti-aliasing filter circuit and the single chip with the A/D which are connected in turn, wherein the single chip with the A/D controls the analog switch and the programmable amplifying circuit. The method overcomes multi-channelizing of the conventional sampling method and skillfully adopts a single channel to replace multiple channels, and the single-channel time-sharing multiplexing sampling circuit is designed according to the method; therefore, the instantaneity, accuracy and reliability of the sampling signals are improved.
Description
Technical field
The present invention relates to a kind of single-channel time-sharing multiplexing sampling method and sample circuit thereof, refer in particular to the alternating current sampling method and the sample circuit thereof that are applied to the three-phase alternating current system.
Background technology
At present, the distributing system of generally using at industrial control field generally is divided into three grades: procedure level, monitoring level and management information level.Distributing system is to be scattered in the system that on-the-spot the process monitoring unit based on microcomputer, process control unit, picture and text active station and main frame (host computer) integrate.It has adopted local area network technology, and a plurality of process monitorings, active station and host computer are interconnected, and communication function is strengthened, and information transfer rate is accelerated, and handling capacity strengthens, for the integrated management of information provides the foundation.In monitoring level, to main control equipment, install predetermined algorithm and handle, and sends control command to input-output apparatus by main control equipment by the control network transmission for the signal that on-the-spot input-output apparatus produces.The management information level is positioned at the upper strata, communicates by letter exchange message with field control station by system's net.
Ac sampling device is positioned at this one deck of input-output apparatus, and in the three-phase and four-line power transmission network, known sampling apparatus is made up of three-phase sampling resistor, amplifier, sampling hold circuit, waveform transformation circuit, A/D translation circuit and single-chip microcomputer.Need the original signal of the comprehensive electrical quantity of sampling to have 7: Ua, Ub, Uc, Ia, Ib, Ic, IO, can calculate a plurality of electrical quantitys in view of the above, wherein common as power (P/Q/S), electric energy (Wh/varh), power factor (cos), line voltage (Vab/Vbc/Vca) etc., these parameters are correlation signal, need two or more signals to carry out the association sampling.
There is following shortcoming in existing AC Data (hyperchannel): the first, and original signal has 7, just needs 7 passages, and each passage all needs amplifying circuit and anti-aliasing filter circuit correspondingly, can cause the input circuit complexity like this; The second, the measurement result out of true that asynchronous-sampling was caused when there was the discreteness that is difficult to eliminate in interchannel and measures the multichannel correlation signal all can be brought certain influence to AC sampling, makes measurement result occur than large deviation; The 3rd, input signal is many, and bigger variation often takes place the duty of components and parts, and a series of drifts can take place, and inevitably produces the error that is difficult to revise, and causes instrument can't continue normal use; The 4th, can realize the multistage amplification of signal, if hyperchannel will be realized such function, just need each passage all to add multistage amplifying circuit, make hardware circuit complicated more.
Summary of the invention
The object of the invention is to overcome the deficiencies in the prior art, and a kind of method of sampling and sample circuit thereof are provided, and guarantees that the signal of sampling is real-time, accurate, high, the good reliability of precision, and design is tending towards oversimplifying.
The technical scheme that the present invention solves prior art is a kind of single-channel time-sharing multiplexing sampling method, and its step is as follows:
Step 1, the multichannel original signal is by by becoming single channel signal behind the monolithic processor controlled analog switch;
Step 2, single channel signal output termination amplifying circuit amplifying signal;
Step 3, the output termination filtering circuit filtering high-frequency signal of amplifying circuit;
Step 4, the single-chip microcomputer of the output terminal tape splicing A/D of filtering circuit is sampled to sampled signal and is calculated.
In the step 4 single-chip microcomputer to sampled signal sample and Program for Calculation comprise sampling routine and calculation procedure.
The master routine of software program is: after signal enters single-chip microcomputer, start sampling routine, judge by program whether the acquisition time data finish, if sampling does not finish, then continue the acquisition time data, if sampling finishes, then according to the effective value of image data counting circuit voltage, and according to current/voltage value selection enlargement factor program, and then parameters such as rated output, power factor.In calculation procedure, single-chip microcomputer according to formula, calculates parameters such as electric current, voltage, power, frequency to sampled data, returns the time sharing sampling data program after calculating is finished and continues next group signal to be gathered calculating, so circulation.
Wherein, judge and to enable the T1 interrupt routine when whether the time sharing sampling program finishes.The T1 interrupt routine is triggered A/D and interrupted export procedure by interrupt routine inlet, timing successively to be formed, and the A/D interrupt routine is used for judging whether the time sharing sampling data finish.After single-chip microcomputer enters A/D interruption entry program, at first preserve sampled data, judge then whether this phase current voltage sample finishes, if, then put the sampling end mark, and select next phase voltage current channel, enter the master routine circulation by interrupting export procedure, if sampling does not finish, then judge it is voltage channel or electric current channel, if the voltage channel by program, then select the electric current channel and select enlargement factor, if the electric current channel is then selected the voltage channel and selected enlargement factor, finally enter the master routine circulation by interrupting export procedure end interrupt program.
A kind of single-channel time-sharing multiplexing sample circuit of using single-channel time-sharing multiplexing sampling method, single-chip microcomputer U5 by analog switch U1, pga circuit, anti-aliasing filter circuit and band A/D connects to form successively, single-chip microcomputer U5 control analog switch U1 and the pga circuit of band A/D.Multichannel current/voltage forceful electric power signal changes into weak electric signal by mutual inductor and enters analog switch U1, the scale-of-two input end A of analog switch U1, B, C are under the single-chip microcomputer U5 of band A/D control, make original signal Ua, Ub, Uc, Ia, Ib, Ic, IO the orderly conducting of each passage at analog switch U1, once only gather the in-phase current voltage signal, original signal becomes single channel signal and delivers to the pga circuit input port.Pga circuit is formed by connecting in turn by normal signal amplified current and weak signal amplifying circuit, the normal signal amplifying circuit comprises operational amplifier U3 and the peripheral circuit of being made up of resistance, and the weak signal amplifying circuit comprises operational amplifier U4, analog switch U2 and the peripheral circuit of being made up of resistance.After the multichannel weak signal entered pga circuit, the single-chip microcomputer U5 of band A/D selected enlargement factor according to sampled value control last time analog switch U2, realize that small-signal divides rank to amplify, and interference source does not obtain amplifying, and has improved the sampling precision of small-signal.Join the filtering high-frequency signal through classification amplifying signal output terminal and anti-aliasing filter circuit.The anti-aliasing filter circuit is made up of resistance R 7, capacitor C 5.Delivering to the A/D port of single-chip microcomputer U5 behind the signal of filtering high frequency samples.
Compared with prior art, beneficial effect of the present invention is: the first, and this method adopts single channel to replace hyperchannel, simplicity more; The second, a kind of single-channel time-sharing multiplexing circuit of being designed by this method changes the multi-channel circuit of original technology into the single channel circuit, and time-sharing multiplex has been simplified circuit greatly; The 3rd, after hyperchannel changes single channel into, avoided interchannel discrete type, the out of true that asynchronous-sampling is caused when having reduced owing to measurement multichannel correlation signal; The 4th, the acquisition time data program, calculate the current/voltage effective value and select parameter program such as enlargement factor, rated output, power factor, frequency according to the current/voltage value, improved the degree of accuracy of measuring.
Description of drawings
Fig. 1 is the master routine figure of sampling routine of the present invention;
Fig. 2 is the T1 interrupt routine figure of sampling routine of the present invention;
Fig. 3 is the A/D interrupt routine figure of sampling routine of the present invention
Fig. 4 is a theory diagram of the present invention;
Fig. 5 is circuit theory diagrams of the present invention;
Embodiment
Design proposal of the present invention is to overcome the deficiencies in the prior art, the multi-channel sampling method that provides a kind of single-channel time-sharing multiplexing sampling method to replace prior art, and design a kind of single-channel time-sharing multiplexing sample circuit according to this method, to guarantee that the signal of sampling is real-time, degree of accuracy is high, good reliability, make design be tending towards oversimplifying.Be elaborated with reference to accompanying drawing below in conjunction with embodiment, so that technical characterictic of the present invention and advantage are carried out more deep annotation.
A kind of single-channel time-sharing multiplexing sampling method, its step is as follows:
Step 1, the multichannel original signal is by by becoming single channel signal behind the monolithic processor controlled analog switch;
Step 2, single channel signal output termination amplifying circuit amplifying signal;
Step 3, the output termination filtering circuit filtering high-frequency signal of amplifying circuit;
Step 4, the single-chip microcomputer of the output terminal tape splicing A/D of filtering circuit is sampled to sampled signal and is calculated.
In the step 4 single-chip microcomputer to sampled signal sample and Program for Calculation comprise sampling routine and calculation procedure.
As shown in Figure 1, the master routine of software program is: after signal enters single-chip microcomputer, start sampling routine, judge by program whether the acquisition time data finish,, then continue the acquisition time data if sampling does not finish, if sampling finishes, select the enlargement factor program then according to the effective value of image data counting circuit voltage, and according to the current/voltage value, and then parameters such as rated output, power factor.In calculation procedure, single-chip microcomputer according to formula, calculates parameters such as electric current, voltage, power, frequency to sampled data, returns the time sharing sampling data program after calculating is finished and continues next group signal to be gathered calculating, so circulation.
Wherein, judge and to enable the T1 interrupt routine when whether the time sharing sampling program finishes.As Fig. 2, interrupt routine is triggered A/D and interrupted export procedure by interrupt routine inlet, timing successively to be formed.A/D interrupt routine as shown in Figure 3, judge whether the time sharing sampling data finish, enter the interruption entry program, at first preserve sampled data, judge then whether this phase current voltage sample finishes, if then put the sampling end mark, and select next phase voltage current channel, enter the master routine circulation to interrupting export procedure, if sampling does not finish, then judge it is voltage channel or electric current channel, if the voltage channel by program, then select the electric current channel and select enlargement factor, if the electric current channel is then selected the voltage channel and selected enlargement factor, finally enter the master routine circulation by interrupting export procedure end interrupt program.
Below calculation procedure is further specified.After sampling finishes, according to the effective value of image data counting circuit voltage, and according to current/voltage value selection enlargement factor program, and then parameters such as rated output, power factor.In calculation procedure, single-chip microcomputer according to following formula, calculates parameters such as electric current, voltage, power, frequency to sampled data.
1, effective value calculates:
In the formula, N---uniform sampling number of each cycle
u
i---the voltage sample value that i is ordered
i
i---the current sampling data that i is ordered
The comprehensive conversion coefficient of Ku---voltage effective value is a definite value
K
I---the comprehensive conversion coefficient of current effective value is a definite value
2, power calculation:
In the formula, i is an i+N/4 primary current sampled value.As i+N/4 during greater than N, i is taken as i-3N/4.Can prove when N 〉=3, calculate by formula (1), (2), (3), (4) formula and will not produce the discretize error of calculation.
When sampling, because be not to sample simultaneously, thus can not directly multiply each other, according to the trapezoidal algorithm of complexification
Sampling Ui current value I i=(Ii+I (i+1))/2 constantly, just Ui electric current constantly equals the average of adjacent twice current value.In like manner, the formula of three phase power P, Q is as follows:
The current/voltage effective value of calculating sampling signal has more real-time, accuracy, reliability with respect to the multi-channel sampling signal thus.
A kind of theory diagram of the single-channel time-sharing multiplexing sample circuit of using single-channel time-sharing multiplexing sampling method as shown in Figure 4, circuit is connected to form by the single-chip microcomputer U5 of analog switch U1, pga circuit, anti-aliasing filter circuit, band A/D successively, single-chip microcomputer U5 control analog switch U1 and the pga circuit of band A/D.Single-chip microcomputer U5 control analog switch U1 and the pga circuit of band A/D, the conducting in order under the control of the single-chip microcomputer U5 of band A/D of each channel switch of analog switch U1, once only gather the in-phase current voltage signal, changing original signal is single channel signal, single channel signal enters the pga circuit amplifying signal, by anti-aliasing filter circuit filtering high-frequency signal, deliver to the single-chip microcomputer U5 sampling of band A/D then, finish signals sampling.
Further specify below in conjunction with circuit theory diagrams, as Fig. 5.Plurality of voltages electric current forceful electric power signal changes into weak electric signal by mutual inductor, scale-of-two input end A, B, the C of the single-chip microcomputer U5 control of band A/D, make original signal Ua, Ub, Uc, Ia, Ib, Ic, IO the orderly conducting of each passage at analog switch U1, once only gather the in-phase current voltage signal, in-phase current voltage signal 64 points of sampling respectively, original signal becomes single channel signal and delivers to the pga circuit input port.Single-chip microcomputer timer T1 makes this phase voltage, current signal alternately enter pga circuit through analog switch U1 every analog switch U1 of (electrical network cycle/128) time control.
Pga circuit is formed by connecting in turn by normal signal amplified current and weak signal amplifying circuit, the normal signal amplifying circuit comprises operational amplifier U3 and the peripheral circuit of being made up of resistance, and the weak signal amplifying circuit comprises operational amplifier U4, analog switch U2 and the peripheral circuit of being made up of resistance.After the multichannel weak signal enters pga circuit, because Chip Microcomputer A/D precision is limited, it is low to measure the small-signal precision, in order to improve precision, single-chip microcomputer is selected suitable enlargement factor according to the effective value control U2 of electric current and voltage last time, realize that small-signal divides rank to amplify, and interference source does not obtain amplifying, and has improved the sampling precision of small-signal.
Join the filtering high-frequency signal through classification amplifying signal output terminal and anti-aliasing filter circuit.The anti-aliasing filter circuit is made up of resistance R 7, capacitor C 5.This circuit major function is the above high-frequency signal of filtering sample frequency, avoids high-frequency signal that effective measuring-signal is influenced.
The A/D port of delivering to single-chip microcomputer U5 behind the current and voltage signals filtering high-frequency signal is sampled and the effective value of calculating voltage electric current.
Claims (9)
1. single-channel time-sharing multiplexing sampling method, its step is as follows:
Step 1, the multichannel original signal is by by becoming single channel signal behind the monolithic processor controlled analog switch;
Step 2, single channel signal output termination amplifying circuit amplifying signal;
Step 3, the output termination filtering circuit filtering high-frequency signal of amplifying circuit;
Step 4, the single-chip microcomputer of the output terminal tape splicing A/D of filtering circuit is sampled to sampled signal and is calculated.
2. a kind of single-channel time-sharing multiplexing sampling method according to claim 1 is characterized in that: the described single-chip microcomputer of step 4 is sampled by sampled signal and Program for Calculation comprises sampling routine and calculation procedure.
3. a kind of single-channel time-sharing multiplexing sampling method according to claim 2, it is characterized in that: described sampling routine is made up of master routine, T1 interrupt routine and A/D interrupt routine, judge in the master routine image data enters the T1 interrupt routine when whether finishing, and the T1 interrupt routine comprises the A/D interrupt routine.
4. a kind of single-channel time-sharing multiplexing sampling method according to claim 2, it is characterized in that: described calculation procedure calculates the effective value of current/voltage according to image data, and according to current/voltage value selection enlargement factor program, and then parameters such as rated output, power factor.
5. the single-channel time-sharing multiplexing sample circuit of each described method among the application rights 1-4, it is characterized in that: by the analog switch that connects successively, pga circuit, the anti-aliasing filter circuit, the single-chip microcomputer of band A/D port is formed, single-chip microcomputer U5 control analog switch U1 and the pga circuit of band A/D, the conducting in order under the control of the single-chip microcomputer U5 of band A/D of each channel switch of analog switch U1, once only gather the in-phase current voltage signal, changing original signal is single channel signal, single channel signal enters the pga circuit amplifying signal, then by anti-aliasing filter circuit filtering high-frequency signal, deliver to the single-chip microcomputer U5 sampling of band A/D, finish signals sampling.
6. a kind of single-channel time-sharing multiplexing sample circuit according to claim 5, it is characterized in that: analog switch U1 is made up of chip IC 1, scale-of-two input end A, B, the C of the single-chip microcomputer U5 control analog switch U1 of band A/D, make original signal Ua, Ub, Uc, Ia, Ib, Ic, IO the orderly conducting of each passage at analog switch U1, once only gather the in-phase current voltage signal, original signal becomes single channel signal.
7. a kind of single-channel time-sharing multiplexing sample circuit according to claim 6, it is characterized in that: described single channel signal output termination pga circuit is realized the classification amplification, pga circuit is formed by connecting in turn by normal signal amplified current and weak signal amplifying circuit, the normal signal amplifying circuit comprises operational amplifier U3 and the peripheral circuit of being made up of resistance, and the weak signal amplifying circuit comprises operational amplifier U4, analog switch U2 and the peripheral circuit of being made up of resistance.
8. a kind of single-channel time-sharing multiplexing sample circuit according to claim 7, it is characterized in that: described process classification amplifying signal output terminal is connected with the anti-aliasing filter circuit, the filtering high-frequency signal, the anti-aliasing filter signal circuit is made up of resistance R 7, capacitor C 5.
9. a kind of single-channel time-sharing multiplexing sample circuit according to claim 8 is characterized in that: described signal output part through filtering is connected with band A/D single-chip microcomputer U5, realizes signals sampling and calculating.
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102368667A (en) * | 2011-03-25 | 2012-03-07 | 杭州士兰微电子股份有限公司 | Offline type AC-DC (Alternating Current-Direct Current) control circuit and converting circuit comprising same |
| CN102914691A (en) * | 2012-10-19 | 2013-02-06 | 冶金自动化研究设计院 | Device with adaptive function and method for detecting three-phase alternating current voltage and current |
| CN105738725A (en) * | 2016-01-29 | 2016-07-06 | 山东鲁能智能技术有限公司 | Multipath alternating current split-phase synchronous sampling method and circuit |
| CN106713703A (en) * | 2017-02-17 | 2017-05-24 | 深圳东昇射频技术有限公司 | Amplification system and amplification method for video output signal of radio frequency power probe |
| CN109752986A (en) * | 2017-11-08 | 2019-05-14 | 南京天擎汽车电子有限公司 | Sampling control method and sampling control mechanism, electronic equipment and storage medium |
| CN110221559A (en) * | 2019-06-11 | 2019-09-10 | 珠海格力电器股份有限公司 | Pin multiplexing circuit and its control method |
| CN111464093A (en) * | 2020-04-11 | 2020-07-28 | 常州瑞创电器科技有限公司 | Sampling method of air conditioner permanent magnet synchronous motor |
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2010
- 2010-01-12 CN CN201010019359A patent/CN101726658A/en active Pending
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102368667A (en) * | 2011-03-25 | 2012-03-07 | 杭州士兰微电子股份有限公司 | Offline type AC-DC (Alternating Current-Direct Current) control circuit and converting circuit comprising same |
| CN102368667B (en) * | 2011-03-25 | 2013-10-16 | 杭州士兰微电子股份有限公司 | Offline type AC-DC (Alternating Current-Direct Current) control circuit and converting circuit comprising same |
| CN102914691A (en) * | 2012-10-19 | 2013-02-06 | 冶金自动化研究设计院 | Device with adaptive function and method for detecting three-phase alternating current voltage and current |
| CN102914691B (en) * | 2012-10-19 | 2014-12-03 | 冶金自动化研究设计院 | Device with adaptive function and method for detecting three-phase alternating current voltage and current |
| CN105738725A (en) * | 2016-01-29 | 2016-07-06 | 山东鲁能智能技术有限公司 | Multipath alternating current split-phase synchronous sampling method and circuit |
| CN105738725B (en) * | 2016-01-29 | 2018-11-13 | 山东鲁能智能技术有限公司 | Multichannel AC split-phase synchronous sampling method and circuit |
| CN106713703A (en) * | 2017-02-17 | 2017-05-24 | 深圳东昇射频技术有限公司 | Amplification system and amplification method for video output signal of radio frequency power probe |
| CN106713703B (en) * | 2017-02-17 | 2019-09-03 | 深圳东昇射频技术有限公司 | A kind of radio-frequency power probe video output signals amplification system and amplification method |
| CN109752986A (en) * | 2017-11-08 | 2019-05-14 | 南京天擎汽车电子有限公司 | Sampling control method and sampling control mechanism, electronic equipment and storage medium |
| CN110221559A (en) * | 2019-06-11 | 2019-09-10 | 珠海格力电器股份有限公司 | Pin multiplexing circuit and its control method |
| CN111464093A (en) * | 2020-04-11 | 2020-07-28 | 常州瑞创电器科技有限公司 | Sampling method of air conditioner permanent magnet synchronous motor |
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Application publication date: 20100609 |