CN111682887B - Power carrier communication method - Google Patents
Power carrier communication method Download PDFInfo
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- CN111682887B CN111682887B CN202010687570.8A CN202010687570A CN111682887B CN 111682887 B CN111682887 B CN 111682887B CN 202010687570 A CN202010687570 A CN 202010687570A CN 111682887 B CN111682887 B CN 111682887B
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B3/00—Line transmission systems
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B3/00—Line transmission systems
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- H04B3/04—Control of transmission; Equalising
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Abstract
A power line carrier communication method belongs to the field of power line carrier communication. It includes: the voltage of a communication signal of a metering device loaded on a power line and the voltage of a communication signal of a non-metering device loaded on the power line are respectively positioned at two sides of a reference voltage, the communication signal of the metering device in 1 information element period and any one or more communication signals of the non-metering device with the same time length cannot be completely neutralized, the communication signal of the non-metering device in 1 information element period and any one or more communication signals of the metering device with the same time length cannot be completely neutralized, and the period of the communication signal of the metering device and the period of the communication signal of the non-metering device are obviously different from the power frequency loaded on the power line. The power carrier communication method can reduce mutual interference among power frequency alternating current, the communication signals of the metering device and the communication signals of the non-metering device, and is beneficial to separating the communication signals of the metering device and the communication signals of the non-metering device from a power line.
Description
Technical Field
The invention relates to the technical field of power line carrier communication, in particular to a power line carrier communication method.
Background
In communication technology, a carrier wave (carrier signal or carrier) is an electric wave generated by an oscillator and transmitted over a communication channel, and is modulated to transmit voice or other information. The carrier frequency is usually higher than the frequency of the input signal, which is a high frequency signal that is modulated onto a high frequency carrier as if it were riding a train of high-speed rails or an airplane, and then transmitted and received. A carrier wave is the physical basis and vehicle upon which information (voice and data) is conveyed. The unmodulated periodic oscillating signal is referred to as a carrier wave, which may be a sine wave or a non-sine wave (e.g., a periodic pulse train), and the carrier wave is modulated and referred to as a modulated signal, which contains the full-wave characteristics of the modulated signal. The frequency of the sinusoidal carrier is generally required to be much higher than the bandwidth of the modulated signal, otherwise aliasing occurs, distorting the transmitted signal.
Power Line Communication (PLC) is a special Communication method for voice or data transmission using a Power Line as an information transmission medium. Because the power carrier technology can utilize the existing power line, the laying cost is extremely low. The signals to be transmitted in the power system comprise a communication signal of a metering device and a communication signal of a non-metering device, wherein the communication signal of the metering device has extremely high requirement on the accuracy of data transmission, and the communication signal of the non-metering device needs to be prevented from interfering with the communication signal of the metering device.
Disclosure of Invention
The invention aims to provide a power carrier communication method to reduce mutual interference among power frequency alternating current, communication signals of a metering device and communication signals of a non-metering device.
In order to solve the technical problems, the following technical scheme can be selected according to the needs:
a power carrier communication method includes: the voltage of a metering device communication signal loaded on a power line and the voltage of a non-metering device communication signal loaded on the power line are respectively positioned on two sides of a reference voltage, the metering device communication signal in 1 information element period and any one or more non-metering device communication signals with the same time length cannot be completely neutralized, the non-metering device communication signal in 1 information element period and any one or more metering device communication signals with the same time length cannot be completely neutralized, and the period of the metering device communication signal and the period of the non-metering device communication signal are obviously different from the power frequency loaded on the power line.
Preferably, the power supply frequency of the power line is fGModulating a metering device communication signal for a power line carrier and loading the metering device communication signal on a power line, wherein the metering device communication signal comprises a first polarity high level signal and a first polarity low level signal; the voltage interval of the first polarity high level signal is
The voltage interval of the first polarity low level signal is
Voltage interval
Can be distinguished from voltage interval
And using a filter to obtain the metering device communication signal consisting of the first polarity high level signal and the first polarity low level signal from the power line.
Preferably, the first polarity high level signal has a frequency interval of
The first polarity low level signal has a frequency interval of
A periodic signal of
Set of notes
The filter is used for obtaining the frequency belonging to the set f from the power line+The first polarity high level signal and the first polarity low level signal form the metering device communication signal.
Preferably, the power supply frequency of the power line is fGModulating a non-metering device communication signal for a power line carrier and loading the non-metering device communication signal on a power line, wherein the non-metering device communication signal comprises a second polarity high level signal and a second polarity low level signal; the voltage interval of the second polarity high level signal is
The voltage interval of the second polarity low level signal is
Voltage interval
Can be distinguished from voltage interval
And using a filter to obtain the non-metering device communication signal consisting of the second polarity high level signal and the second polarity low level signal from the power line.
Preferably, the second polarity high level signal using frequency interval is
The second polarity low level signal has a frequency interval of
A periodic signal of
Set of notes
The filter is used for obtaining the frequency belonging to the set f from the power line-The second polarity high level signal and the second polarity low level signal.
Preferably, the metering device communication signal includes a first polarity sine wave signal, the first polarity sine wave signal includes a first polarity high level signal and a first polarity low level signal, the first polarity high level signal is an integral of the first polarity high amplitude signal in N periods, the first polarity low level signal is an integral of the first polarity low amplitude signal in N periods, N is an even number, and N is greater than or equal to 2; the non-metering device communication signals adopt second polarity sine wave signals, the second polarity sine wave signals comprise second polarity high level signals and second polarity low level signals, the second polarity high level signals are integrals of the second polarity high amplitude signals in M periods, the second polarity low level signals are integrals of the second polarity low amplitude signals in M periods, M is an even number, and M is larger than or equal to 2.
Preferably, the frequency of the metering device communication signal is significantly different from the frequency of the non-metering device communication signal.
Compared with the prior art, the invention has the beneficial effects that:
1. according to the invention, the frequencies of the communication signal of the metering device and the communication signal of the non-metering device are obviously different from the power frequency on the power line, so that the communication signal of the metering device and the communication signal of the non-metering device can be taken out from the power line through the filter; by distinguishing the polarities of the metering device communication signal and the non-metering device communication signal loaded on the power line, the metering communication signal and the non-metering device communication signal can be distinguished obviously under the condition that the current of the metering device communication signal and the current of the non-metering device communication signal cannot be completely neutralized. Therefore, the power carrier communication method can reduce the mutual interference among the power frequency alternating current, the communication signals of the metering device and the communication signals of the non-metering device, and is beneficial to separating the communication signals of the metering device and the communication signals of the non-metering device from the power line.
2. By obviously distinguishing the voltage interval of the first polarity high-level signal from the voltage interval of the first polarity low-level signal, the information carried by the communication signal of the metering device can be obtained through decoding.
3. By obviously distinguishing the voltage interval of the second polarity high-level signal from the voltage interval of the second polarity low-level signal, the information carried by the communication signal of the non-metering device can be obtained through decoding.
4. In even cycles, the integral of the unipolar sine wave type signal is a gradually increasing curve; in even cycles, the integral difference between the unipolar sine wave type high-amplitude signal and the unipolar sine small-group type low-amplitude signal is gradually increased in the even cycles, so that the unipolar sine wave type high-amplitude signal and the unipolar sine small-group type low-amplitude signal are favorably distinguished; for instantaneous fluctuations of the frequency within the filter pass frequency in an even number of cycles, the integral is generally sinusoidal, i.e. the integral value is substantially 0, so that interference of the instantaneous fluctuations with the signal is excluded.
Drawings
Fig. 1 is a schematic diagram of a power carrier encoding module and a power carrier decoding module for communication by applying the power carrier communication method of the present invention.
Fig. 2 is a structural diagram of a metering carrier communication signal and a non-metering carrier communication signal transmitted by applying the power carrier communication method of the present invention.
Detailed Description
The present invention is described below in terms of embodiments in conjunction with the accompanying drawings to assist those skilled in the art in understanding and implementing the present invention. Unless otherwise indicated, the following embodiments and technical terms therein should not be understood to depart from the background of the technical knowledge in the technical field.
In the present invention, a significant distinction means that the relevant signals can be separated using electronic devices or electronic components. For example, the filters may separate waves of different frequencies; the difference in amplitude can be separated by means of integration or by means of a combination of fourier transformation and inverse fourier transformation.
The invention discloses a power carrier communication method, which comprises the following steps: the voltage of a metering device communication signal loaded on a power line and the voltage of a non-metering device communication signal loaded on the power line are respectively positioned on two sides of a reference voltage, the metering device communication signal in 1 information element period and any one or more non-metering device communication signals with the same time length cannot be completely neutralized, the non-metering device communication signal in 1 information element period and any one or more metering device communication signals with the same time length cannot be completely neutralized, and the period of the metering device communication signal and the period of the non-metering device communication signal are obviously different from the power frequency loaded on the power line. The voltage of the communication signal of the metering device loaded on the power line is different from the voltage of the communication signal of the non-metering device loaded on the power line, so that the communication signal of the metering device and the communication signal of the non-metering device can be distinguished through the difference of the voltages; the communication signal of the metering device in 1 information element period and any one or more communication signals of non-metering devices with the same time length cannot be completely neutralized, and the communication signal of the non-metering device in 1 information element period and any one or more communication signals of the metering device with the same time length cannot be completely neutralized, so that the problem that the communication signal of the metering device and the communication signal of the non-metering devices can only be theoretically distinguished when the current of the communication signal of the metering device and the current of the communication signal of the non-metering devices are completely neutralized, but actually, the communication signal of the metering device and the communication signal of the non-metering devices have no influence on a power line is solved; the frequencies of the communication signals of the metering device and the communication signals of the non-metering device are obviously different from the power frequency on the power line, so that the communication signals of the metering device and the communication signals of the non-metering device can be taken out from the power line.
Preferably, the power supply frequency of the power line is fGModulating a metering device communication signal for a power line carrier and loading the metering device communication signal on a power line, wherein the metering device communication signal comprises a first polarity high level signal and a first polarity low level signal; the voltage interval of the first polarity high level signal is
The voltage interval of the first polarity low level signal is
Voltage interval
Can be distinguished from voltage interval
A meter communication signal consisting of a first polarity high level signal and a first polarity low level signal is taken from the power line using a filter. The electrodes have two polarities, positive and negative. The first polarity is for distinguishing from a second polarity described later, and if the first polarity is positive, the second polarity is negative; if the first polarity is negative, the second polarity is positive. Wherein the voltage interval
Can be distinguished from voltage interval
The significant distinction here means that significant distinction can be realized by amplitude in a period corresponding to the same bit signal; or, in the period corresponding to the same bit signal, significant distinction can be realized by an integration mode in the same period. Of course, in other possible embodiments, the first polarity high level signal and the first polarity low level signal may be significantly distinguished by frequency, phase, and the like.
More preferably, the frequency interval for using the first polarity high level signal is
The frequency interval of the first polarity low level signal is
A periodic signal of
Set of notes
Filters for deriving frequency content from power linesAnd f+The first polarity high level signal and the first polarity low level signal. Wherein when
When using a set f that can be taken out+The filter of the internal frequency can take out the communication signal of the metering device from the power line. Theoretically, the first polarity high level signal can be accurate to a frequency point, but actually, the frequency thereof is usually within a range. Preferably, the frequency interval is
And frequency interval
There is a wide overlap interval.
Further preferably, the communication signal of the metering device comprises a first polarity sine wave signal, the first polarity sine wave signal comprises a first polarity high level signal and a first polarity low level signal, the first polarity high level signal is an integral of the first polarity high amplitude signal in N periods, the first polarity low level signal is an integral of the first polarity low amplitude signal in N periods, N is an even number, and N is greater than or equal to 2. The sine wave signal can be distinguished from the pulse signal caused by the on-off of the load of the power grid, and the adverse effect of the pulse signal of the type on the communication signal of the metering device is avoided. Generally, when a sine wave signal is modulated and the sine wave signal within one period forms a single-polarity sine wave signal, taking the positive polarity sine wave signal as an example, the negative polarity portion of the sine wave signal is filtered out, which results in one positive polarity half-wave plus one blank segment, or the negative polarity portion of the sine wave is rectified into a positive polarity portion, which results in two positive polarity sine wave half-waves.
Preferably, the power supply frequency of the power line is fGModulating a non-metering device communication signal for a power line carrier and loading the non-metering device communication signal on a power line, wherein the non-metering device communication signal comprises a second polarity high level signal and a second polarity low level signal;the voltage interval of the second polarity high level signal is
The voltage interval of the second polarity low level signal is
Voltage interval
Can be distinguished from voltage interval
And using a filter to obtain the non-metering device communication signal consisting of the second polarity high level signal and the second polarity low level signal from the power line.
More preferably, the second polarity high level signal use frequency interval is
The second polarity low level signal has a frequency interval of
A periodic signal of
Set of notes
The filter is used for obtaining the frequency belonging to the set f from the power line-The second polarity high level signal and the second polarity low level signal.
Further preferably, the non-metering device communication signal is a second polarity sine wave signal, the second polarity sine wave signal includes a second polarity high level signal and a second polarity low level signal, the second polarity high level signal is an integral of the second polarity high amplitude signal in M periods, the second polarity low level signal is an integral of the second polarity low amplitude signal in M periods, M is an even number, and M ≧ 2.
Preferably, the frequency of the metering device communication signal is significantly different from the frequency of the non-metering device communication signal. When the frequency of the communication signal of the metering device is obviously different from that of the communication signal of the non-metering device, the situation that a certain bit of the communication signal of the metering device is completely neutralized with a certain bit of the communication signal of the non-metering device when the amplitude of the communication signal of the metering device is close to that of the communication signal of the non-metering device can be avoided.
FIG. 1 is a schematic diagram of a power carrier encoding module and a power carrier decoding module for communication using the power carrier communication method of the present invention, in which a voltage U is showninFor voltage at input end of power line, voltage UoutFor the output terminal voltage of the power line, the frequency f is the power frequency of the power line, the frequency f1Is the frequency of the first carrier signal encoder A11, frequency f2Is the frequency, voltage U, of the second carrier signal encoder A210Is a reference voltage, voltage
Voltage is the conduction voltage difference of diode D21
Is the conduction voltage difference of the diode D22.
Fig. 2 shows a power line carrier communication device of the present invention transmitting a metering carrier communication signal and transmitting a non-metering carrier communication signal. In the figure, the signal representing the first information element of the measurement carrier signal is a positive double-half sine wave, the signal representing the second information element of the measurement carrier signal is null, and the frequency of the signal representing the first information element is the same as the frequency of the signal representing the second information element. The signal representing the third information element of the unmeasured carrier signal is a negative double-half sine wave, the signal representing the fourth information element of the unmeasured carrier signal is null, and the frequency of the signal representing the third information element is the same as the frequency of the signal representing the fourth information element. Overall, the signal representing the first information element differs significantly in both frequency and amplitude from the signal representing the third information element.
The metering device communication signal corresponds to a positive polarity signal, the first polarity high-amplitude signal is a positive polarity double-half-wave sine signal, and the first polarity low-amplitude signal is a 0-level blank signal. Therefore, when constructing the communication signal of the metering device, it is necessary to control the number of bits of the communication signal, for example, n +3 bits. The start bit (i.e., bit 1) is a positive polarity double half-wave sine signal, and the end bit (i.e., bit n + 3) is a bipolar double half-wave sine signal. In order to avoid decoding errors caused by interference of a 0-level blank signal or a bipolar double-half-wave sine signal, a check bit can be set between the start bit and the end bit, and the check bit can be 1 bit or 2 bits or more.
The non-metering device communication signal corresponds to a negative polarity signal, the second polarity high-amplitude signal is a negative polarity double half-wave sine signal, and the second polarity low-amplitude signal is a 0-level blank signal. Therefore, when constructing the communication signal of the metering device, it is necessary to control the number of bits of the communication signal, for example, m +3 bits. The start bit (i.e., bit 1) is a positive polarity double half-wave sine signal, and the end bit (i.e., bit m + 3) is a bipolar double half-wave sine signal. In order to avoid decoding errors caused by interference of a 0-level blank signal or a bipolar double-half-wave sine signal, a check bit can be set between the start bit and the end bit, and the check bit can be 1 bit or 2 bits or more.
The amplitude and the frequency of the first polarity high-amplitude signal are different from those of the second polarity high-amplitude signal.
The invention is described in detail above with reference to the figures and examples. It should be understood that in practice it is not intended to be exhaustive of all possible embodiments, and the inventive concepts of the present invention are presented herein by way of illustration. Without departing from the inventive concept of the present invention and without any creative work, a person skilled in the art should, in all of the embodiments, make optional combinations of technical features and experimental changes of specific parameters, or make a routine replacement of the disclosed technical means by using the prior art in the technical field to form specific embodiments, which belong to the content implicitly disclosed by the present invention.
Claims (7)
1. A power carrier communication method, comprising: the voltage of a communication signal of a metering device loaded on a power line and the voltage of a communication signal of a non-metering device loaded on the power line are respectively positioned at two sides of a reference voltage, the current of the communication signal of the metering device in 1 information element period and the current of any one or more communication signals of the non-metering device with the same time length cannot be completely neutralized, the current of the communication signal of the non-metering device in 1 information element period and the current of any one or more communication signals of the metering device with the same time length cannot be completely neutralized, and the period of the communication signal of the metering device and the period of the communication signal of the non-metering device are obviously different from the power frequency loaded on the power line; a significant difference means that the relevant signals can be separated using electronic devices or components.
2. The power carrier communication method of claim 1, wherein the power line is powered at a frequency fGModulating a metering device communication signal for a power line carrier and loading the metering device communication signal on a power line, wherein the metering device communication signal comprises a first polarity high level signal and a first polarity low level signal; the voltage interval of the first polarity high level signal is
The voltage interval of the first polarity low level signal is
Voltage interval
Can be distinguished significantlyIn the voltage interval
And using a filter to obtain the metering device communication signal consisting of the first polarity high level signal and the first polarity low level signal from the power line.
3. The method according to claim 2, wherein the first polarity high level signal is used in a frequency range of
The first polarity low level signal has a frequency interval of
A periodic signal of
Set of notes
The filter is used for obtaining the frequency belonging to the set f from the power line+The first polarity high level signal and the first polarity low level signal form the metering device communication signal.
4. The power carrier communication method of claim 1, wherein the power line is powered at a frequency fGModulating a non-metering device communication signal for a power line carrier and loading the non-metering device communication signal on a power line, wherein the non-metering device communication signal comprises a second polarity high level signal and a second polarity low level signal; the voltage interval of the second polarity high level signal is
The voltage interval of the second polarity low level signal is
Voltage interval
Can be obviously distinguished from a voltage interval
And using a filter to obtain the non-metering device communication signal consisting of the second polarity high level signal and the second polarity low level signal from the power line.
5. The method according to claim 4, wherein the second polarity high level signal is used in a frequency interval of
The second polarity low level signal has a frequency interval of
A periodic signal of
Set of notes
The filter is used for obtaining the frequency belonging to the set f from the power line-The second polarity high level signal and the second polarity low level signal.
6. The power carrier communication method of claim 1, wherein the metering device communication signal comprises a first polarity sine wave signal, the first polarity sine wave signal comprises a first polarity high signal and a first polarity low signal, the first polarity high signal is an integral of the first polarity high amplitude signal over N cycles, the first polarity low signal is an integral of the first polarity low amplitude signal over N cycles, N is an even number, and N ≧ 2; the non-metering device communication signals adopt second polarity sine wave signals, the second polarity sine wave signals comprise second polarity high level signals and second polarity low level signals, the second polarity high level signals are integrals of the second polarity high amplitude signals in M periods, the second polarity low level signals are integrals of the second polarity low amplitude signals in M periods, M is an even number, and M is larger than or equal to 2.
7. The method of claim 6, wherein the frequencies of the metrology device communication signals are substantially different from the frequencies of the non-metrology device communication signals.
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| EP1677270A1 (en) * | 2004-12-31 | 2006-07-05 | Hejl Tomas | Method of automatic meter reading |
| CN202929819U (en) * | 2012-11-12 | 2013-05-08 | 河南开启电力实业有限公司 | Simple low-pressure metering and remote meter reading system |
| CN210323193U (en) * | 2019-04-16 | 2020-04-14 | 杨胜锋 | Intelligent electric energy remote metering system |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8831077B2 (en) * | 2010-07-01 | 2014-09-09 | Texas Instruments Incorporated | Communication on a pilot wire |
| WO2014128725A1 (en) * | 2013-02-20 | 2014-08-28 | Sunil Gopinath | A system for measuring and reporting resource usage |
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2020
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1677270A1 (en) * | 2004-12-31 | 2006-07-05 | Hejl Tomas | Method of automatic meter reading |
| CN202929819U (en) * | 2012-11-12 | 2013-05-08 | 河南开启电力实业有限公司 | Simple low-pressure metering and remote meter reading system |
| CN210323193U (en) * | 2019-04-16 | 2020-04-14 | 杨胜锋 | Intelligent electric energy remote metering system |
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